Nigeria like most developing nations still faced with a higher rate of short birth interval (SBI), and its associated consequences, such as adverse maternal and child health outcomes. This study aimed to determine the distribution and factors associated with SBI in rural and urban Nigeria. The data for this study were extracted from the 2018 Nigeria Demographic and Health Survey (2018 NDHS). Statistical analyses were descriptive analysis and binary logistic model. The proportions of SBI in rural and urban Nigeria were 20.7% and 20.3% respectively. Women’s age, geopolitical region, education level, and the number of children ever born were significantly associated with SBI in rural and urban Nigeria. Maternal Wealth index and antenatal care visits were only significant in rural while working status was only significant in urban Nigeria after controlling for other factors. Higher odds of SBI for middle class women than poor women , and increase in ANC visits reduces the odds of having SBI: 4–7 visits  and > 7visits . There were slight disparities in the prevalence of short birth intervals in rural and urban areas. Wealth index and ANC visits were only significant in rural Nigeria. Public health awareness campaigns should be strengthened to drive the importance of birth spacing techniques such as the utilization of modern contraceptives and breastfeeding in all the geo-political regions and across all age strata. Women particularly those residing in the rural areas should be encouraged to advance their education to at least a secondary level and enlightened on the importance of ANC. The World Health Organization (WHO) currently recommends an interval between the last live birth and the next pregnancy of at least 24 months4, and any birth less than this is considered a short birth interval (SBI). Short birth intervals lead to adverse maternal, perinatal, neonatal, and child health outcomes6. Short birth interval is associated with under-five mortality and low birth weight8. Globally, it is estimated that 25% of births still occur less than 24 months, and most of these births were observed in Central Asia (33%) and Sub-Saharan Africa (20%)9.Birth spacing, also known as an inter-birth interval (IBI), or inter-pregnancy interval refers to how soon after a prior pregnancy a woman becomes pregnant or gives birth again. Optimal birth spacing  is incontrovertibly linked to better health outcomes for both mothers and babies10. This suggests that Nigeria, like other developing nations, still is faced with a high rate of short birth intervals. Other African countries with similar rates include Rwanda: 20%, Uganda: 25.3%, Cameroon: 21.3% and Ethiopia: 24.9%, and these high rates were attributed to a lack of access to family planning options11. A study in Abuja, the capital city of Nigeria reported that 50% of women had birth to pregnancy intervals of fewer than 24 months, while 14 (3.5%) had birth to pregnancy intervals of greater than 60 months1. A similar study in Enugu, Nigeria also reported that the median inter-birth interval was 21.5 months2.In Nigeria according to the 2018 Nigeria Demographic and Health Survey stood at 25% with a median birth interval of 30.9 months13. Interbirth interval is also influenced by sociodemographic, economic, and birth history6. Fayehun et al. reported that the type of contraceptives used, living in rural or urban settings, wealth index, husbands’ occupation, and sex of preceding children determined birth intervals14. Having more female children and the last birth been a female significantly reduced birth intervals in the quest for a male child14. The use of contraceptives for birth spacing was also seen to be affected by male child preference where the last child is a female, a woman would like to use a short-acting contraceptive in order not to wait too long to get a male child6.Few factors have been associated with birth intervals. Some of these are direct factors such as frequency of sexual activity, use of contraceptives, postpartum in fecundability, abortion, and sterility while indirect factors include socioeconomic and cultural factors11, inadequate birth spacing was rated as the highest risk faced by African women during pregnancy compared to other pregnancy-related outcomes15. Some studies in Nigeria and elsewhere have also shown a significant association between preceding birth intervals and under-five mortality20. However, studies on the determinants of the short birth interval using nationally representative data such as Nigeria Demographic and Health Survey (NDHS) are sparse in Nigeria. Existing studies were Hospital-based23, and each of them was only limited to the city or town in which the Hospital is located. This study bridged the gap by estimating the determinants of short birth intervals at the national level using NDHS data.While adequate birth spacing is considered as a very significant factor for the health of women and their childrenGiven the above, it is important to gain a deeper understanding of the disparities existing among women living in rural and urban Nigerians in terms of interbirth interval. This study, therefore, aimed to determine the distribution and factors associated with short birth intervals in rural and urban Nigeria.The data for this study were extracted from the 2018 Nigeria Demographic and Health Survey (NDHS) conducted by the National Population Commission (NPC) and ICF international. Being a national survey, it elicits information from women and men of reproductive age across the 36 states and the Federal Capital Territory (FCT) Abuja, nominated through a stratified two-stage cluster sampling technique. The NDHS, like other Demographic and Health Surveys (DHS) is conducted every five years in the consenting low- and middle-income countries.The data involved 41,821 women residing in rural and urban Nigeria, extracted from women data of 2018 NDHS.4. The explanatory variables were sociodemographic and health care-seeking characteristics.The outcome variable in this study was preceding birth interval which was recoded as < 24 months and ≥ 24 months. This is based on the definition of the World Health OrganizationThe explanatory variables and their categories were:Mother’s age: < 20/20–29/30–39/ ≥ 40 years.Child’s sex: Male/female.Mother’s Religion: Christianity/Islam/Others.Current Region of residence: North-central/North-east/ North-west/South-east/South-south/South-west.Current place of residence: Urban/rural.Mother’s educational level: None/primary/secondary/higher.Marital status: Never married/married.Employment status: Unemployed/employed.Wealth index: Poor/middle/rich.Number of children ever born: 0–2/ 3–4/ > 4.Antenatal care visits: None/1–3/4–7/ > 7 visits.We analyzed the data using univariate, bivariate and multivariate techniques. At the univariate level, proportion was used to describe the characteristics of the respondents; at the bivariate technique level, chi-square was utilized to assess the association between the characteristics and the birth interval; while binary logistic regression was fitted at the multivariate level to determine the influence of these factors on birth interval to explain the disparities in the birth interval between rural and urban women.P-value < 0.05. Analysis was arried out using Stata version 15.0 s.The outcome variable, the birth interval, was categorized and coded as (≥ 24 months = 0 and < 24 months = 1) and used in the logistic regression. Firstly, we described the characteristics. Secondly, we assessed the association between the explanatory variables and the birth interval; and lastly, only the significant variables were included in the multiple binary logistic regression model. Three logistic regression models were fitted for the study: the entire country, rural Nigeria, and urban Nigeria. To account for the complex nature of the DHS data, we adjusted for sampling weight, clustering, and stratification. The measure of associations was the odds ratio, and its statistical significance was assessed at 95% confidence interval excluding unit and p is the probability of an event to occur  and 1-p is the probability of the event not occurring , The logistic regression model is expressed as:All methods were carried out in accordance with relevant guidelines and regulations. In addition, all experimental protocols and ethical approval were obtained from the National Health Research. Ethics Committee of Nigeria (NHREC) (ref. no. NHREC/01/01/2017). Written informed consent was obtained from all subjects and/or their legal guardian(s).P < 0.05), except the sex of the child (P = 0.749), and so was excluded in further analysis. The proportion of < 24 months and ≥ 24 months birth intervals were respectively 20.6% vs 79.4% for Nigeria, 20.3% vs 79.7% for urban Nigeria and 20.7% vs 79.3% for rural Nigeria, as shown in Fig. The distributions of the characteristics and their association with birth interval are shown in Table Table There was significantly higher odds of having a short birth interval among rural women living in only the South-east  and South-south . While among women residing in the urban areas, living in the North-east , South-east  and South-south  were significantly more likely to have short birth interval compared with those living in the North-central; whereas living in south-west urban Nigeria was significantly less likely to have short birth interval compared with those living in the North-central .Whereas women who had no formal education were 61% and 58% significantly higher odds of having short birth interval than women with higher education in urban Nigeria  and rural Nigeria  respectively. Furthermore, employed women residing in the rural areas had lower odds of having short birth interval than unemployed women , though not statistically significant. Whereas, in urban areas employed women had significantly lower odds of having short birth interval than unemployed women . Regarding the household wealth index, middle wealth index women living in rural areas were 1.19 times more likely to have short birth intervals compared to poor women . But in the urban areas, middle wealth index women had a lower odds of having short birth intervals than the poor women, though not statistically significant .Women in rural Nigeria who have had three to four deliveries and above were less likely to have a short birth interval  and  respectively than those with two deliveries or less. In urban Nigerian only women who had more than 4 children were significantly less likely to have a short birth interval than women who had two children or fewer . But those who had 3–4 children had lower odds of having short birth intervals compared with women who had two children or less, though not statistically significant. Women who attended antenatal care at least four times during pregnancy had lower odds of having short birth intervals in only rural Nigeria than those who did not attend: Four to seven ANC visits  and more than seven ANC visits .11 as well as in Brazil12. The observed differences could be attributed to the prevalent socio-geographical and cultural differences in the studied areas. These results indeed call for urgent action considering the adverse consequences of a short birth interval to mothers and children. Though all the variables were significantly associated with short birth intervals at the bivariate level, the multivariate analysis showed that maternal age at childbirth, geopolitical region, number of children ever born, and ANC visits were all statistically associated with short birth intervals. Although we found the sex of the child not be significant in the current study, the quest for male children or children in the Africa context, Nigeria inclusive, could affect birth interval among women.This study was designed to assess short birth interval and its determinant with a focus on rural–urban variation in Nigeria. We defined a short birth interval as having another birth before 24 months of having a preceding birth. The overall prevalence of short birth intervals in Nigeria was 20.6%. While rural and urban areas of Nigeria were 20.7% and 20.3% respectively. This result is higher than the SBI reported in Rwanda, but lower compared to findings in some other African countriesWhile the educational level was significant in urban areas, the household wealth index was significantly associated with short birth intervals in rural areas at a multivariate level. Though, both variables were significant in Nigeria.24. Fecundity could be a possible explanation for this, as younger women are highly fecund than older women and the likelihood of younger women using contraceptives is less compared to older women because they have a high desire to bear children24. More so, younger women are likely to be less privileged and as such may not afford more birth spacing techniques compared to older women as shown in a study conducted in Finland25.This study showed that the odds of having a short birth interval decrease as the mother’s age at birth of the child increases. In the other words, the odds of having the next child within 24 months is reduced as women get older, and this result agreed with previous studies27. This could be attributed to the relatively lower information on birth intervals and the nonavailability of modern contraceptives in rural areas compared to urban areas. Women who have information about short birth intervals through any media channel are expected to have a better understanding of the negative impact of short birth intervals on maternal and children’s health. As a result, women who have no exposure to any media are more likely to experience short birth intervals than those who have media exposure29.The study revealed that women residing in rural Nigeria were more likely to have short birth intervals compared with those residents in urban areas. This again substantiates the essence of this study, as it is believed that contributing factors to short birth interval is dependent on the place of residence, and as such could not be the same. This is consistent with reports of similar studies which indicate a relatively higher occurrence of short birth intervals in rural areas compared to urban areas30.Whereas all the zones in the country except North-west were associated with high odds of having a short birth interval at the national level and rural areas, only south-east and south-south were significantly associated with high odds of having short birth interval among urban residents. This could be because of the under-utilization of contraceptives in all the regions in rural and urban Nigeria by both men and women3.The study also revealed that women that attended the WHO minimum of four antenatal care visits were less likely to have a short birth interval than those that attended less than the minimum visits in rural Nigeria. This is because ANC attendees have access to health education that explains the consequences of short birth intervals and information and materials that will enable them to prolong pregnancy to their desired time. Having more than two children was less likely to have a short birth interval than having less for women residing in both rural and urban areas of Nigeria. This is true because these women that had more children may have achieved their desired family size and may feel less pressure or be in less of a hurry to get pregnant again33. The explanation might be attributed to the fact that better-educated women are more likely to use contraception to delay their inter-birth intervals and may also be exposed to more health education. Furthermore, there is a likelihood that literate women may be engaged in careers that are not well-suited to childbearing34.This study has observed that Maternal education is protective of short birth intervals as an increase in educational attainment leads to a decrease in the likelihood of experiencing short birth intervals. This implies that educated women were more likely to have spaced births than non-educated women. This finding is consistent with other studies in Ethiopia and Pakistan35. The possible explanation for this could be that privileged women may have more access to health care education and information and could afford health care services that apply logically enhanced short interbirth interval31. Furthermore, there was a disparity in the association between working status and short birth in rural and urban Nigeria. Whereas in urban areas, working-class women had significantly lower odds of having short birth interval, it was not significant in rural areas. The insignificance of working status in rural areas could be that in rural Nigeria it is difficult to distinguish between working and non-working women because all women are involved in one activity to other. The significant association between employment status to short birth interval found in this study was consistent with other studies done abroad37. The reason has been that working-class women can afford modern contraceptives that could be used to delay pregnancy to enable them to put in some months in their job after maternity leave. Married women have higher odds of experiencing short birth intervals than never-married women. The reason may be that married women are less likely to use contraceptives than never-married women38.The household wealth index was also identified as a significant determinant of short birth interval in rural Nigeria. This study revealed that the odds of experiencing short birth intervals were less common in households in the rich and middle wealth index than in the poor wealth index. This is consistent with studies carried out in Ethiopia, Saudi ArabiaThe major strength of this study was the fact that it utilized nationally representative data collected through standardized questionnaires and valid sampling procedures. While the limitation was on the ground that the design was cross-sectional which involves some missing information on reproductive indicators. Our findings should be interpreted with caution as we could not establish causation.This study has demonstrated disparities in short birth interval in rural and urban Nigeria, by estimating prevalence and identifying factors influencing short birth intervals in these areas. There were slight disparities in the prevalence of short birth intervals in rural and urban areas. This is evident in the contributing factors as almost all the same factors such as maternal age at childbirth, geopolitical regions, educational attainment, and the number of children ever born were significantly associated with short birth intervals in both areas. It only differed in wealth index and the ANC visits for rural areas. Thus, policymakers and the relevant stakeholders should intensify existing strategies geared toward maintaining optimal birth spacing to ensure the well-being of mothers and children in rural and urban areas of Nigeria. Public health awareness campaigns should be strengthened to drive the importance of birth spacing techniques such as the utilization of modern contraceptives and breastfeeding in all the geo-political regions and across age strata. Finally, women, particularly in rural areas should be encouraged to advance their education to at least a secondary level and enlightened on the importance of ANC.


Background: Gender incongruent children report lower self-perceptioncompared to the norm population. This study explored differences inself-perception between children living in their gender role assigned at birthand children living in their experienced gender role.Method: The self-perception questionnaire was administered to 312children referred to the Center of Expertise on Gender Dysphoria ‘AmsterdamUMC’. Social transition status was determined by parental interviews. 2  by 2 (sex assigned at birth) ANCOVA’s were conducted.Results: Children living in their assigned gender role reportedcomparable self-perception to children living in their experienced gender role.Birth assigned girls living in their assigned gender role reported poorerself-perception on ‘athletic competence’, compared to girls living in theirexperienced gender role. Birth assigned boys living in their assigned genderrole reported poorer on ‘scholastic competence’ and ‘behavioral conduct’compared to boys living in their experienced gender role.Conclusions: Social transition did not show to affectself-perception. Self-perception was poorer for birth assigned boys living intheir experienced gender role. For birth assigned girls this was reversed.Future studies should give more insight in the role of social transitions inrelation to child development and focus on other aspects related toself-perception. StudiesThe view on how to best counsel gender incongruent children has evolved over time andis much under debate. Based on the field In the watchful waiting approach, all gender identification outcomes are equallydesirable. This approach states to be reticent in actively initiating an earlysocial transition. Arguments for this statement is that not all children continue toexperience gender incongruence and/or desire a medical transition, the likelihood ofsocial stigmatization may increase, and the effect on gender development is unclear.Counselling based on watchful waiting aims to protect children from potential socialrisk factors but still allows the child to explore one’s gender identity developmente.g., .Also in the affirming approach, all gender identification outcomes are equallydesirable . AffirmiThe approaches mentioned have different views about an early social transition of achild’s gender role. Knowledge in the literature on the effect of an early socialtransition is however limited. Clinicians have advised caution to stimulate an earlysocial transition because not all children continue to experience genderincongruence in later life and the uncertainty what the effect of a transition mayhave on the development of the child e.g., .FurtherConsidering the above we conclude that there is still a lot to learn about thedevelopment of children who go through an early social transition and those who donot. Research on the influence of social transition is needed to shed more light onthe concerns mentioned above. In this vein, the current study investigates whetherthere are differences in various aspects of self-perception between genderincongruent children who went through a social transition and those who did not.Mage = 9.4, SD = 1.2), 37.8%(n = 118) were living in the gender role of the sexassigned at birth , and 62.2% (n =194) in their experienced gender identity . The parents of all children provided informed consent to use datacollected as part of the intake, diagnostic, and counseling for scientificresearch. Official approval of this study by our medical ethical commission wasnot required as the Medical Research Involving Human Subjects Act (WMO) does notapply to the study. Informed consent procedure and data handling was donefollowing the Guidelines for Good Clinical Research Practice.Current study sample consisted of 312 children referred to the Center ofExpertise on Gender Dysphoria at the Amsterdam UMC (location VU), theNetherlands, between 1997–2016. Of the 312 children was used. The original interview instrument wasdeveloped and validated by From 1997 till 2012, the parental interviews at intake included questionsabout their child’s social transition. The interview questions wereabout the child’s clothing style and affirmed use of pronouns  and name. In 2012 these interview questionswere formalized in a checklist. Children who were using a name andpronouns and wearing clothing and hairstyle congruent to their assignedsex at birth were categorized as children living in their assigned sexat birth. Children who presented themselves using a name and pronounsand, or, wearing clothing and have hairstyle incongruent to theirassigned gender at birth were categorized as children living in theirexperienced gender.Self-perception was measured by the Dutch version of the self-perceptionprofile for children SPPC; . This qun = 166) who visited the Center for a diagnostictrajectory stopped visiting the Center after one or two sessions mainly becausethey had enough support in their environment to deal with their feelings. Themeasurement of self-perception took place during a psychological assessmentsession, generally after 2 or 3 sessions. Data on background information such asdemographics, the intensity of experienced gender incongruence, and socialtransition status were part of the diagnostic trajectory. To investigate therepresentativeness of the sample, preliminary analyses were first conducted. Inthese analyses, background information was compared between the current sampleand the children who stopped visiting the Center. As part of the preliminaryanalyses, we compared within our study sample the background information betweenthose who are living in the sex assigned at birth (n = 118)versus those who are living in the experienced gender identity(n = 194). Regarding these preliminary analyses, a seriesof analysis of variance (ANOVA) were used to compare age and mean scores betweengroups and chi-square analyses to compare percentages.Not all children in the age range of 7–13 referred to the Center of Expertise onGender Dysphoria at the Amsterdam UMC (location VU), the Netherlands between1997–2016 are included in the current study. Because some children by 2 (sex assigned at birth) analyses of variances werecarried out. When background information variables were significantly associatedwith social transition status, they were included as covariates in theseanalyses.Children living in their experienced gender identity were significantly older andreported higher scores on cognitive and affective gender incongruence see  comparedWhen the background information was only investigated for those assigned at birthas females, it revealed that there was a significant effect on cognitive genderincongruence. Those living in their experienced gender identity showed higherscores on this aspect of the gender identity interview than those living in thegender role related to the sex assigned at birth. No significant differenceswere found on other background variables for females (assigned at birth) whowere and were not living in their experienced gender identity see .For those who were assigned at birth as males, it was found that socialtransition status was significantly related to age, cognitive and affectivegender incongruence. Children who were assigned at birth as males and living inthe experience gender identity were, compared to those living in the identityassigned at birth, older, and reported significantly higher scores on cognitiveand affective gender incongruence. No significant differences were found onother background variables for males (assigned at birth) who were and were notliving in their experienced gender identity see .There was no significant main effect for social transition status on scholasticcompetence. However, the main effect for sex assigned at birth showed thatfemales reported higher scores on scholastic competence than males. Also, therewas a significant interaction effect between social transition and sex assignedat birth. Only for children who were assigned at birth as males, there was asignificant effect for social transition status: Those living in the experiencedgender identity reported lower scores on scholastic competence than those livingin the gender role assigned at birth. This effect of social transition statuswas not found for children who were assigned at birth as female.For social competence, there was no significant main effect for social transitionstatus. However, there was a significant main effect of sex assigned at birth:scores from assigned females at birth were significantly higher on socialcompetence than scores from males assigned at birth. There was no significantinteraction effect between social transition status and sex assigned atbirth.There was no significant main effect for social transition status on athleticcompetence. However, sex assigned at birth was significantly related. This wasalso the case for the interaction between social transition status and sexassigned at birth. Children assigned at birth as females reported higher scoreson athletic competence than those assigned at birth as males. However, based onthe significant interaction effect, the difference between the sexes assigned atbirth were only significant for the children assigned at birth as females andliving in their experienced gender identity.Regarding physical appearance, there was no significant main effect for socialtransition status. Also, social transition status by sex assigned at birth wasnot significantly related to physical appearance. Nevertheless, sex assigned atbirth was significantly related to physical appearance, with higher scores forfemales than for males.For behavioral conduct, there was no significant main effect for socialtransition status, neither for sex assigned at birth. However, the interactionbetween social transition status and sex assigned at birth was significant. Itrevealed that only for those whose sex assigned at birth was male the effect ofsocial transition status was significantly related to behavioral conduct.Children assigned at birth as male living in their experienced gender roleshowed lower scores on behavioral conduct than those living in the assigned sexat birth.There was no significant main effect for social transition status on globalself-worth. Also, the effect of sex assigned at birth was not significant;neither that of the interaction of social transition status and sex assigned atbirth.Current study aimed to examine if the self-perception between clinically referredgender incongruent children differed between those who did and those who did not gothrough a social gender transition. No differences were found between children witha different social transition status. Based on previous studies where genderincongruent children showed to be at risk for developing a negative self-concept and otheRegarding sex assigned at birth some significant findings were found. Genderincongruent children assigned at birth as females generally reported a more positiveself-perception than children assigned at birth as males. This is in line withfindings by The stereotypical valuation of masculinity and femininity could also be theexplanation why we found interaction effects between social transition and sexassigned at birth. Children assigned at birth as males living in their experiencedgender role reported a poorer self-perception on scholastic competence, andbehavioural conduct compared to children assigned at birth as males living in theirassigned roles. Whereas children assigned at birth as females and living in theirexperienced gender role scored higher on athletic competence compared to childrenassigned at birth as females and living in their assigned gender role. Behavioralconduct is an interesting concept to highlight as it is related to perceivednormative and moral behaviour. It might be that assigned males at birth who havesocially transitioned perceive their transition as socially unacceptable, contraryto the norm, making them feel more disobedient than assigned males at birth who havenot socially transitioned. Children assigned at birth as males who have sociallytransitioned might experience more restrictions on their gender expressions.Oppositional behaviour, anger, and sadness precipitate specifically whenrestrictions on gender expression and gender identity are attempted .A general limitation in research on gender identity expression is the lack ofvalidated instruments and the use and interpretation of terminology. Theavailable instruments have substantial limitations . AlthougA methodological limitation of our study is that findings are based on across-sectional design. In this vein it cannot be ruled out that children whounderwent a social transition may have had a poorer psychological well-beingbeforehand, compared to the children who did not socially transition or visaversa, which makes it difficult to draw causal conclusions about the effect of asocial transition on psychological well-being. To avoid this, future studiesshould use a prospective longitudinal design. In addition, it is advised toinclude factors that focus on family and peer support. Furthermore, studies witha qualitative design will also be valuable to provide more insight inconsiderations of parents and children regarding a social transition inchildhood related to gender identity and mental health.In this study, the methodological study design, the approach of a socialtransition was binary. Social transition, however, is not a static choice, norcan it be captured in a singular decision whether to undergo or not. A socialtransition is a timely and dynamic process  . AnindIt seems advisable for clinicians to be cautious in formulating and providinggeneral advice regarding a social gender transition. An individual approach ongender identity exploration in clinical practice seems to be best suited andmore important to meet the individual needs. This means that in the guidance ofgender incongruent youth and their families, clinicians should inform andexplain that the exploration of one’s gender identity is a process, adevelopmental pathway in which all children differ. Many factors, individual,internal, systemic, and external, play important roles for youth to considersteps aligning their birth assigned gender with their experienced gender.Whether this is within or outside the broad spectrum of gender identity orwhether this is aligned with their assigned gender at birth or not is a processto find out and may not be a clear pathway for every child. To affirm one’sgender identity exploration is not the same as utilizing an affirmative orwatchful waiting approach. Admitting an affirming attitude entails, in our view,creating an open environment where the situation, needs and desires of the childand caregivers are explored and discussed in relation to what we know fromstudies and clinical experience. And where through the best possible way issought for the child and family to grow up and develop in a safe and healthymanner.To conclude, we did not observe differences in self-perception between clinicallyreferred gender incongruent children who did or did not socially transition. Onedoes need to be aware of the gender differences regarding the effects of socialtransition. For some children a social transition might be alleviating, where forothers it might not. An individualized approach in counseling children andcaregivers in the decision to go through (and shape) a social gender transition isin the best interest of the child’s current and future functioning. Much more hasyet to be understood about early social transitions in relation to child developmentin order to derive more suitable general suggestions for practical use.


The efficacy of dapagliflozin and empagliflozin in sodium-glucose cotransport-2 inhibitors (SGLT-2i) in patients with heart failure (HF) has been discovered. However, which drug could improve varied prognostic outcomes has not been elucidated. Hence, we compared their efficacies on the prognostic improvement of HF.Databases including PubMed, EMBASE, Scopus, Google Scholars, and the Cochrane Library were searched for all related randomized controlled trials (RCTs) published from inception to 13 October 2021. Network meta-analyses were performed to generate matrices to show the effect size for pairwise comparison regarding all the interventions.Eventually a total of 11 RCTs were included in this study. For the primary endpoints, dapagliflozin was comparable with empagliflozin in hospitalization for HF, and empagliflozin  decreased the risk of exacerbation of HF over dapagliflozin. For the secondary endpoints, dapagliflozin was comparable with empagliflozin in cardiovascular (CV) death /hospitalization for HF, and for CV death, dapagliflozin  significantly reduced mortality over the placebo. For the tertiary endpoints, dapagliflozin  significantly decreased the mortality over empagliflozin in all-cause death, and neither drug significantly increased the risk of hypoglycemia.Overall, 10 mg/day dapagliflozin may be the optimal recommendation for its premium and comprehensive effect on improving the prognosis of patients with HF compared to 10 mg/day empagliflozin. Heart failure (HF), a major public health problem with considerable morbidity and mortality, is often accompanied by various degrees of progressively pathological enlargement of the left ventricular and abnormal cardiac remodeling , 2. In rThe results of the EMPA-REG OUTCOME trial were the first to demonstrate that empagliflozin in sodium-glucose cotransport-2 inhibitor (SGLT-2i) was not only effective in controlling blood glucose in patients with type 2 diabetes but also in reducing the risk of cardiovascular (CV) death and hospitalization for HF, and the results implied that patients with HF without diabetes may benefit from it as well . UndoubtWith its many clinical applications and the publication of large randomized controlled trials (RCTs), SGLT-2i was verified to have CV and renal protective effects in addition to its hypoglycemic mechanism . Its diuThis meta-analysis was conducted and reported in line with Cochrane and PRISMA  guidelines . DatabasInclusion criteria: (1) study subjects were patients with all types of chronic heart failure ; (2) the drugs used were dapagliflozin, empagliflozin, and placebo; (3) drug doses of both dapagliflozin and empagliflozin were 10 mg per day; (4) RCTs; and (5) reported at least one prognosis endpoint of interest.Exclusion criteria: (1) non-RCTs; (2) total number of study cases was <80; (3) drug dosage was inconsistent with the conventional recommended dosage; and (4) full texts were unavailable.Unlike acute HF, CHF is more stable and the clinical symptoms may not be obvious, but there is also a risk of worsening or decompensation. Integrating the diagnostic criteria of CHF from all included studies collectively, CHF was diagnosed as: (1) patients with New York Heart Association functional class (NYHAFC) II-IV symptoms and LVEF ≤ 50%; (2) NYHAFC I symptoms and LVEF ≤ 40%; (3) LVEF > 40% and 6-min walk test distance ≥ 100 m and ≤ 350 m; (4) NT-proBNP level > 300 pg/ml, or NT-proBNP level > 900 pg/ml in patients with atrial fibrillation.A standardized data form was utilized to extract all data by two reviewers independently and Cochrane risk of bias tools was used for RCTs . DiscrepThe primary endpoints were hospitalization for HF and exacerbation of HF . The seI2 < 50% and p > 0.01, a fixed effect model would be adopted, otherwise a random-effect model would be performed. Network meta-analyses (NMA) were executed according to frequentist framework in Stata software by the random-effects model. Matrices (shown as OR and 95% CI) regarding each endpoint were generated to show the pairwise comparison of all interventions. To enhance the stability of the results, the assessment of both gross and loops inconsistency between direct and indirect comparison were performed. Assessment of small sample effect was performed using funnel plots. P < 0.05 was considered to be statistically significant.All analyses were performed by the application of STATA version 15.0 and Review Manager software version 5.4. Odds ratio (OR) with 95% confidence intervals (95% CI) was calculated to evaluate the binary variables. If We included the studies from inception to 13 October 2021 and obtained 2,921 publications. After screening and removing duplicates, 293 studies were required to be screened based on inclusion criteria after full-text reading, and finally, 12 studies –8, 12–18The specific details of risk-of-bias assessments of the included studies are shown in All direct meta-analyses were the comparison of SGLT-2i with placebo shown in , and thevs. placebo was 0.76  and dapagliflozin was 0.68 (95%CI. 0.58–0.80). Network meta-analysis of hospitalization for HF showed that the OR of dapagliflozin vs.empagliflozin was 0.90 . For exacerbation of HF, the OR of empagliflozin vs.placebo was 0.68  and dapagliflozin was . The OR of network meta-analysis of empagliflozin vs.dapagliflozin was 0.70 .For hospitalization for HF, the OR of empagliflozin vs. placebo was 0.71 (95%CI 0.62–0.82) and empagliflozin was 0.74 . Network meta-analysis of CV death/hospitalization for HF showed that the OR of dapagliflozin vs.empagliflozin was 0.95 . For CV death, the OR of dapagliflozin vs. placebo was 0.78 , whereas the OR of empagliflozin was 0.90 . The OR of dapagliflozin vs. empagliflozin was 0.87 .For CV death/hospitalization for HF, the OR of dapagliflozin vs.placebo was 0.77 (95%CI 0.66–0.91), whereas the OR of empagliflozin was 0.96 . Network meta-analysis of all-cause death showed that the OR of dapagliflozin vs.empagliflozin was 0.80 . As for hypoglycemia, the OR of dapagliflozin vs.placebo was 0.85  and the OR of empagliflozin was 0.92 . The OR of dapagliflozin vs.empagliflozin was 0.92 .For all-cause death, the OR of dapagliflozin The overall and loops inconsistency did not exist in all endpoints.vs. empagliflozin with regard to the above endpoints. The dose of the drug was also chosen exclusively as the recommended 10 mg per day. We excluded some studies because they used mixed drug doses and reported confounding results  on macular densa cells and therefore did not activate the RAAS system . It alsoFor exacerbation of HF, we also found that both dapagliflozin and empagliflozin were effective in preventing this type of prognosis in patients relative to the application of placebo. In the meantime, empagliflozin at a dose of 10 mg performed much better. Exacerbation of HF was included in the study as a composite outcome variable, for which part of the mechanism has already been mentioned above. The other part was that SGLT-2i increased hepatic acetone body synthesis, reduced urinary acetone body excretion, increased myocardial acetone body feedstock available, produced more ATP, and reduced myocardial oxygen consumption, which led to a more efficient myocardial energy supply . As a reAbnormalities in blood–lipid metabolism played an important role in predisposing to CV death. Studies have shown that SGLT-2i significantly reduced total cholesterol (TC) and triglyceride (TG) levels and decreased small dense LDL-C, which significantly increased the risk of CV death because of its long intracirculatory cycle, its ability to cross the arterial wall, and its susceptibility to oxidation . It had We considered that all-cause death influenced by SGLT-2i was because CV death was so heavily dominant within it, as there was no definitive mechanism to explain its exact effect beyond CV. After analysis, it was found that dapagliflozin at 10 mg was more protective than empagliflozin and placebo. Dapagliflozin showed a stronger protective effect compared to empagliflozin because empagliflozin studies contained a large number of HFpEF patients who suffered from multiple comorbidities  and were often faced with a high risk of non-cardiac deaths .The SGLT-2i lowered blood glucose primarily by lowering the renal glucose threshold and promoting urinary glucose excretion. In patients with HF with normal blood glucose levels, this effect was significantly reduced. In this study, dapagliflozin and empagliflozin at 10 mg orally daily did not increase the risk of severe hypoglycemia compared to placebo, and the effects of both SGLT-2i were generally similar. This was in line with previous research findings .Firstly, to reduce within-group variability in the empagliflozin treatment group, we examined only the difference between the 10 mg dose of empagliflozin and placebo. We observed some 25 mg doses mixed in the treatment groups of some studies, but we had to discard the results of this part of the study because we could not break down its effect in some of the studies. This also made this study miss the exploration of the dose-effect. Secondly, the duration of follow-up was not united in some of the included studies, which somewhat increased the occurrence of time-related reporting bias. Thirdly, the proportions of cardiac function classes were not exactly similar within each study endpoint, making the within-group heterogeneity of some of the results high, but the combined effect did not change reversibly when this type of study was excluded. Finally, due to the limited inclusion of results for comparison, the volume of literature reported for some of the analyses is not sufficient, and further expansion of the literature is needed to verify the validity of the results in this study.In our study, the priority of dapagliflozin in decreasing all-cause death and CV death over empagliflozin and placebo was obvious. Moreover, dapagliflozin showed equivalent effect with empagliflozin on hospitalization for HF and CV death/hospitalization for HF, and both of them were significantly lower than the placebo, despite the fact that empagliflozin showed a clear superior efficacy over dapagliflozin in exacerbation of HF, and none of them increased the risk of hypoglycemia.Considering the above results collectively, 10 mg/day dapagliflozin may be the optimal recommendation for its premium and comprehensive effect on improving the prognosis of patients with HF compared to 10 mg/day empagliflozin. However, considering that Empagliflozin study cohorts contained large numbers of HFpEF patients with multiple comorbidities which placed them at high risk for non-CV deaths, further studies are still needed to verify the reliability of the recommendation.The original contributions presented in the study are included in the article/ZS and WL were responsible for screening articles, extracting all data, and applied the Cochrane Collaboration's tool to assess the risk of bias. XH was responsible for theoretical guidance and decision-making in case of disagreement. ZS, FG, and WL were responsible for article writing and data analysis. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Aims:Socio-economic conditions in early life are important contributors to cardiovascular disease – the leading cause of mortality globally – in later life. We studied coronary heart disease (CHD) and stroke in adulthood among people born out of wedlock in two historical periods: before and during World War II in Finland. Methods: We compared offspring born out of wedlock before (1934–1939) and during (1940–1944) World War II with the offspring of married mothers in the Helsinki Birth Cohort Study. The war affected the position of unmarried mothers in society. We followed the study subjects from 1971 to 2014 and identified deaths and hospital admissions from CHD and stroke. Data were analysed using a Cox regression, adjusting for other childhood and adulthood socio-economic circumstances. Results: The rate of out-of-wedlock births was 240/4052 (5.9%) before World War II and 397/9197 (4.3%) during World War II. Among those born before World War II, out-of-wedlock birth was associated with an increased risk of stroke (hazard ratio (HR)=1.44; 95% confidence interval (CI) 1.00–2.07) and CHD . Among those born out of wedlock during World War II, the risks of stroke  and CHD  were similar to those observed for the offspring of married mothers. The p-values for interaction of unmarried×World War II were (p=0.015) for stroke and (p=0.003) for CHD. Conclusions: In a society in which marriage is normative, being born out of wedlock is an important predictor of lifelong health disadvantage. However, this may change rapidly when societal circumstances change, such as during a war. Globally, cardiovascular disease (CVD) is the leading cause of death and years of life lost; close to 18 million people die of CVD every year . Risk fa3In life-course epidemiology, childhood SEP is most commonly indicated by parental occupation and educational attainment . These i6However, due to the small number of studies, the role of the specific sociohistorical context in interpreting the association between a single-parent background and CVD in later life remains unclear. It is likely that rapid changes in society, such as war, may affect the context of single-parent background by changing social norms and socio-economic resources.Particularly in societies where marriage is the parental norm, mothers and their out-of-wedlock children form a non-standard minority that is exposed to social inequality or stigma ,8. In su12Using the Helsinki Birth Cohort Study (HBCS) data across the life course, we investigated the associations between out-of-wedlock birth and coronary heart disease (CHD) and stroke in adulthood. The study participants were born in Helsinki, Finland, from 1934 to 1944 in a society where marriage was normative. Because the studied period includes World War II, we investigated whether the association between out-of-wedlock birth and CHD and stroke differed between those born before and those born during the war. As a secondary analysis, we performed separate analyses for men and women.In Helsinki, 9% of babies were born out of wedlock from 1934 to 1944 . The nucMaternal and child health care developed rapidly during the interwar period . In HelsAlmost 70% of HBCS participants were born during World War II, when Finland became involved in the Winter War (November 1939–March 1940) and the so-called Continuation War (June 1941–September 1944), during which half a million men served in the military forces, that is, 65% of all Finnish men aged 20–49 years . The excThe HBCS includes 13,345 people born in Helsinki in either of the two public maternity hospitals: Helsinki University Women’s Hospital or Helsinki City Maternity Hospital. In addition, to be included in the cohort, one had to visit a child welfare clinic in the city and live in Finland in 1971, when a unique identification number was allocated to each resident of the country. The majority of the study participants also attended school in Helsinki. The original cohort has been described elsewhere ,23. The n=6), widowed (n=22) or divorced (n=17) or who had unclear entries (n=13). We also excluded 32 married mothers with no information on the male caregiver’s occupation and six unmarried mothers with no information on the mother’s occupation. Our final analyses included 12,612 children born to married mothers and 637 (5.9%) children born out of wedlock. Information on breastfeeding was obtained from child welfare clinic records and dummy coded as follows: not breastfed, breastfed less than three months, breastfed three to six months, breastfed six months or more or no information on breastfeeding available. We also used the mother’s highest occupational status which was obtained from birth, childhood welfare clinic and school records [Data obtained from hospital birth records included detailed birth measures and maternal characteristics. We defined the mother’s marital status as married or unmarried at the time of giving birth based on information from birth records as described . We exclorced n=1 or who h records  and dummorced n=1 or who h records . As a co records .Using personal identification numbers, we followed the subjects through national registers from 1971 to 2014 and identified deaths and hospital admissions from CHD and stroke. We used International Classification of Diseases (ICD) codes 410–414 in ICD-8 and ICD-9 and I21–25 in ICD-10 to define CHD and codes 430–439 in ICD-8 and ICD-9 and I60–69 in ICD-10 to define stroke ,28. In FUsing the personal identification number, we obtained information from Statistics Finland on the subjects’ educational attainment, occupational status, income and marital status at five-year intervals between 1970 and 2000. We used the highest educational attainment, occupational status and personal income level achieved. Participants were split into two groups based on marital status in adulthood: ever married  and never married (none of these entries at any time points) as described .We used Cox proportional hazard models as the primary analytical tool with which to examine the associations between maternal marital status at birth and the occurrence of CHD or stroke. Participants were followed from 1971 until the first of these events: death, migration from Finland, hospitalisation for stroke or CHD or reaching 1 January 2014 alive. First, we calculated hazard ratios (HR) separately for two birth periods: those born before World War II (1934–1939) and those born during World War II (1940–1944). Second, we calculated HR for all people born from 1934 to 1944. Men and women were also analysed separately.Supplemental Table SI, we also report the independent effects of covariates that were studied in relation to CHD and stroke outcomes.The data were analysed with three Cox models. Each Cox model was stratified for year of birth using the Cox regression strata function, and models including both sexes were also stratified for sex. Model 1 was an unadjusted model, with mother’s marital status at birth being the only predictor. Model 2 included the following early life factors associated with out-of-wedlock birth: length of gestation, birth weight, birth order, duration of breastfeeding, evacuation abroad during World War II and the mother’s age at giving birth and occupational status in childhood. In model 3, we further added the subject’s own educational attainment and marital status as adulthood covariates. In addition, in We tested potential interactions between sex and mother’s marital status, as well as between period of birth and mother’s marital status in association with cardiovascular outcomes.As supplementary analyses, we repeated our previously published analyses related to out-of-wedlock birth and offspring’s SEP in adulthood, now by period of birth . In thesUnmarried mothers were on average younger, shorter and had a lower body mass index in late pregnancy than married mothers . Regardlp=0.015) and for CHD (p=0.003).We compared offspring’s risk of developing CHD or stroke in later life based on whether they were born before or during World War II. p=0.032) and CHD (p=0.005).We performed a secondary analysis separately among men and women. Among men born before World War II, the association was more robust for stroke, while for CHD, the adjustments for childhood SEP attenuated the association to a borderline significant level. Among women, point estimates of HRs were higher for those born before World War II, although they did not reach statistical significance. No associations between out-of-wedlock birth and CHD or stroke in adulthood were seen among those born between 1940 and 1944. We found no interaction between sex and mother’s marital status at birth. However, the interaction between mother’s marital status at birth and period of birth was statistically significant among men for stroke .As supplementary analyses, we repeated our previously published  analysesOur study shows that people born out of wedlock in a peacetime society in which marriage was the parental norm seem to have a lifelong health disadvantage, as illustrated by higher rates of CHD and stroke in adulthood. This association is only partly explained by other childhood socio-economic indicators or by adult SEP or marital status. However, this relative disadvantage was no longer observed during World War II when society faced a severe strain and exceptional circumstances, such as shortage and rationing. These changes seem to have evened out inequalities that existed in peacetime society.We also repeated our previous analyses related to adult SEP among those born out of wedlock based on period of birth. In terms of adulthood education and occupation but not income, the disadvantage of being born to an unmarried mother was again largely limited to those born before World War II. The most disadvantaged group consisted of children born out of wedlock during the pre-war period.Previous studies suggest that a mother’s marital status may involve a different dimension of social stratification regarding her offspring than SEP based on parental education or occupation. According to these studies, out-of-wedlock origin contributes to later life health disparities ,8–12,14 8A novel finding of our study is that the increased risk of CHD or stroke was found only among those who were born out of wedlock during the pre-war period. The interaction between out-of-wedlock birth and period of birth was statistically significant both for stroke and CHD, implying that the difference between birth periods is very unlikely to have arisen by chance.It is obvious that the war had a broad impact on society. The disordered conditions and temporary separation precluded, temporarily or permanently, some marriages that would have normally followed a conception. Public attitude towards unmarried mothers may have become more permissive . NarrowiThis study has several strengths. We measured early life characteristics such as mother’s marital status, if available, from reliable records. When measuring mother’s occupation, we used the highest occupational status during childhood instead of a single measurement from one specific time point. The register data that we used have been validated and found to be accurate for epidemiological studies. However, some limitations to the present study must also be acknowledged. Data on cohabitations without marriage, other family members or children’s place of residence during the war were not available. Occupational data were classified based on modern standards and do not differentiate between skilled and unskilled workers. These data limitations could be expected to increase random error and result in a more conservative estimate. Moreover, the proportion of out-of-wedlock children in our study was lower than in Helsinki during the time period in question. This would again be expected to lead to a more conservative estimate, that is, a more favourable outcome for those born out of wedlock. Due to high infant mortality among children born out of wedlock, many died before our follow-up. This could in theory diminish the difference between those born out of wedlock and those born to a married mother during World War II, but we believe it is unlikely to cause a large enough bias to explain our results.Finally, even though no direct analogy can be drawn between contemporary and early society in Helsinki, a large number of the people at a higher risk of CVD currently, much like our study participants, are those who are born into societies in which marriage remains the parental norm. Furthermore, from a public health perspective, modern societies may contain minority groups of children experiencing social and economic hardship or stigma with lifelong health effects, similar to those of children born out of wedlock 80 years ago.Our study shows an association between birth out of wedlock and CVD in adulthood among people born before World War II. These results indicate that in a society in which marriage is the parental norm, the mother’s marital status may be an important indicator of early life disadvantage, and that this may vary rapidly when societal circumstances change. Together with other measures, such as parental occupational status, it reflects unfavourable early life circumstances from an alternative viewpoint. The disadvantage that children of unmarried mothers experienced 80 years ago is likely to persist throughout their entire lives.Click here for additional data file.Supplemental material, sj-docx-1-sjp-10.1177_14034948211019792 for Cardiovascular disease in people born to unmarried mothers in two historical periods: The Helsinki Birth Cohort Study 1934–1944 by H. Maiju Mikkonen, Minna K. Salonen, Antti Häkkinen, Clive Osmond, Johan G. Eriksson and Eero Kajantie in Scandinavian Journal of Public HealthClick here for additional data file.Supplemental material, sj-docx-2-sjp-10.1177_14034948211019792 for Cardiovascular disease in people born to unmarried mothers in two historical periods: The Helsinki Birth Cohort Study 1934–1944 by H. Maiju Mikkonen, Minna K. Salonen, Antti Häkkinen, Clive Osmond, Johan G. Eriksson and Eero Kajantie in Scandinavian Journal of Public Health


The aim of this study was to determine the association between the mother’s periodontal condition and perinatal complications, such as preterm birth (PTB) and/or low birth weight (LBW), in a cohort of women in Valencia, Spain. Other related factors, such as tobacco, were also analysed. A prospective cohort study was carried out in a sample of 102 women with a single foetus and ages ranging between 18 and 42 years. Sociodemographic and obstetric variables, caries status, percentage of bleeding, clinical attachment loss (CAL), and probing pocket depth (PPD) data have been collected and analysed. The mean age was 32.4 years, and the BMI was normal. The average weight of new-borns (NB) was 3034 g. A total of 9.8% of the women smoked during their pregnancy. Bleeding percentage was 16.43% (SD 14.81%) and PPDs > 3 mm 8.8 (SD 11.08). The mean of CAL > 0 mm was 1.14 (SD 2.83). The frequency of PTB and LBW was 26%. No statistically significant differences were found between probing depth > 3 mm or CAL > 1 mm, with PTB and/or LBW. Periodontal disease in the mother was not statistically significantly related to either PTB or LBW. Tobacco use during pregnancy showed a statistical significance linked to LBW, but not with PTB. Preterm birth (PTB) is considered to be a birth occurring before the 37th week of gestation. There are two main distinct clinical subtypes of preterm birth: firstly, spontaneous preterm birth, which occurs naturally as a result of spontaneous onset of labour and/or premature rupture of foetal membranes; and secondly, premature birth indicated gynecologically due to a maternal or foetal pathology. Preterm labour is defined as regular contractions accompanied by a cervical change before the usual 37 weeks of gestation. It is initiated by multiple mechanisms, including infection or inflammation, cervical insufficiency, ischemia or uteroplacental haemorrhage, uterine distension, stress, and other immunologically mediated processes. In most cases, a single mechanism cannot be established. It is the synergy of multiple aetiologies and genetic–environmental interactions that can predispose a pregnant patient to PTB .Preterm birth is one of the leading causes of neonatal mortality worldwide. Approximately 1 million preterm infants die each year because of complications stemming from preterm birth ,3. AccorThe assessment of low birth weight (LBW) occurs when the baby’s weight is less than 2500 g; however, when the weight is below 1500 g, it is classified as a case of very low birth weight. Both circumstances pose a public health problem and are the main causes of most biological determinants of infant morbidity and mortality in developed and developing countries . In mostAdverse pregnancy outcomes are also associated with the presence of elevated local and systemic inflammatory mediators and intrauterine infections. Current evidence suggests that adverse outcomes originate mainly from ascending vaginal or cervical infections; another source may be hematogenous spread from known or unknown non-genital sources. Maternal periodontitis represents a potential source of microorganisms that are known to routinely enter the circulatory system, and directly and/or indirectly can influence the health of the maternal–foetal unit . BiologiThe new classification of the AAP/EFP (American Academy of Periodontology and European Federation of Periodontology) aims to clearly identify the clinical entities of periodontitis by introducing operational elements, such as the detection of clinical attachment level (CAL), bleeding on probing (BOP), and probing pocket depth (PPD), to relate diagnosis to prevention and treatment needs. In the context of the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions, it was suggested that a single definition be adopted for the diagnosis of periodontitis .The aim of this study has been to carry out a prospective study to analyse the relationship between the periodontal condition of the pregnant woman in the second trimester and perinatal complications, such as PTB and LBW, and analyse the relation of recognized risk factors, such as tobacco use.A prospective cohort study was carried out in the Department of Obstetrics at Manises Hospital in Valencia, Spain. The sample size was determined by the prevalence of preterm births (<37 weeks) and the prevalence of births with low birth weight (<2500 g) based on published data for the same geographic area; the prevalence of preterm and low birth weight births among the Spanish population was 5.8% in 2010 . A samplWe included 102 women who agreed to participate in the study and met the inclusion criteria of being between weeks 25 and 36 of gestation, with a single foetus, and aged between 18 and 42 years. Cases of multiple gestation, gestation of less than 34 weeks, and those over 37 weeks were excluded. Selection of the participants was made among all the pregnant women who attended their gynaecological pregnancy review in the Obstetrics Clinic of Manises Hospital.For the oral examination, a dental unit, disposable gloves, and masks and a sterile dental kit composed of an intraoral flat mirror No. 5, bent tweezers, and a Williams periodontal probe were available. The examinations were conducted between December 2019 and February 2020, by a single explorer calibration. To ensure validity in the collection of data in fieldwork, the single explorer calibration (GGC) was performed with an experienced explorer that acted as gold standard (JMAS). The agreement was analysed using the intraclass correlation coefficient (ICC), which was 0.859 for all the measurements made, making it an almost perfect agreement according to Fleiss’ kappa. This agreement was not affected by the vestibular/palatine position of the tooth or by its location in the mouth (anterior or posterior), given that it maintained similar values in all positions.The oral examination included a periodontal examination, in which probing depth (PPD) and clinical attachment loss (CAL) of all teeth present were determined and scanned in 6 locations: 3 buccal and 3 lingual or oral. Once the probing had been carried out, the number of bleeding points (BOP) was recorded and patients were classified as having or not having periodontitis according to the criteria of the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions. According to this framework, a patient is considered a case of periodontitis if there is a clinical presentation of one or more of the following: interdental CAL detectable at least 2 non-adjacent teeth, or buccal or oral CAL ≥ 3 mm with pocket depth greater than 3 mm detectable in at least 2 teeth, and that the CAL detected is not attributable to non-periodontal causes, such as gingival recession of traumatic origin, cervical caries that invade the root, CAL in distal of second molars associated with malposition or extraction of the third molar, an endodontic lesion that drains through the marginal periodontium, or a vertical root fracture .A caries scan was also performed using the WHO diagnostic criteria to determine the DMFT index and caries prevalence among participants .In addition, sociodemographic variables about the pregnant women were collected, such as age, level of completed schooling years or studies, medical variables ), habits (smoking), and obstetric history .® file.In the second phase of the study, once the mothers had given birth, we proceeded to collect data related to childbirth—weeks of gestation and the weight of the baby, among others—to classify the birth as normal, low birth weight, or preterm birth. All data were collected in a pseudonymized form in a Microsoft Excelp less than 0.05) was established, with a 95% confidence interval (CI). As a support for the statistical analysis, an Excel program was used, and the data were analysed with the SPSS programme 22.0, IBM® .A descriptive analysis was carried out using frequencies or percentages to describe qualitative variables and a bivariate analysis to establish the relationship between variables. For the comparison of proportions, the Chi-square test was used, along with the T-Student test or Mann–Whitney test to measure compliance with normality. For risk estimation, the odds ratio (OR) was used, and for all the above items, a significance level of 5% , with a restoration rate of 65.3%.Regarding the variables related with childbirth, there were statistically significant differences in the presentation of preterm births with respect to the variables of new-born’s weight, length of time after rupturing of membranes, and assessment of the Apgar test at 5 min of life .Our results showed that neither the state of oral health nor the smoking habits of the mother seemed to significantly condition the presentation of PTB .However, the mother’s tobacco use did have a statistical significance in relation to low birth weight .The frequency of preterm birth was 26, as was that of low-birth-weight births, but not all women who had a preterm birth had low-birth-weight babies. These two circumstances only matched in 17 of the cases.This research has evaluated the relationship between the periodontal condition of the pregnant woman and preterm birth (PTB) and/or low birth weight (LBW) in a cohort of women from Valencia region. Some studies like ours have manifested a positive association between the periodontal condition of the mother with preterm births or neonates with low birth weight ,15,16. AOther cohort studies, conducted with similar methodology to ours, have also shown significant association between mothers with periodontal disease during pregnancy and PTB and/or LBW ,25,26,27While the definitions of preterm birth and low birth weight are well established, no clear consensus on the definition of periodontal disease (PD) has yet been reached in research, which is essential for optimizing the interpretation, comparison, and validation of clinical data . The lacIn our study, we have taken the definition of periodontitis proposed in the 2017 World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions published by Tonetti et al. in 2018. According to this definition, a patient is a case of periodontitis if there is a clinical presentation of: interdental CAL in at least two non-adjacent teeth, or buccal or oral CAL ≥ 3 mm with probing pocket depth (PPD) greater than 3 mm detectable in at least two teeth and this CAL is not attributable to non-periodontal causes, such as gingival recession of traumatic origin, cervical caries that invade the root, CAL in distal zone of second molars associated with malposition or extraction of the third molar, an endodontic lesion that drains through the marginal periodontium, or a vertical root fracture. .A meta-analysis published in 2013  noted thThe presence of an association did not imply causality, although the results should always be interpreted with caution due to the allowance made for confounding variables and the high heterogeneity in the studies .In addition to the mother’s periodontal disease, other risk factors related to prematurity or low birth weight have been studied, such as the mother’s age; the mother’s BMI; occupational exposure; tobacco, drug, and/or alcohol use during pregnancy; changes in the oral microbiome, such as oral dysbiosis ; the usePregnant women at high risk of preterm birth defined by obstetric criteria, such as twin pregnancy and history of previous preterm birth, but without periodontal disease, showed greater gingival inflammation compared to women with a normal course of pregnancy . AccordiSmoking has been recognized as the most important risk factor for periodontitis. Smoker mothers have infants with lower birth weight than non-smoker mothers and, overall, smoker moms have higher infant mortality .However, Manrique-Corredor et al. found in their systematic review that 20% of the studies did not take this risk factor into consideration . AndonovAs for the relationship with the mother’s BMI, a low BMI at the beginning of pregnancy would be a risk factor associated with LBW and/or PTB; women with low weight gain during pregnancy, particularly those who started pregnancy with low BMI, showed an increased PTB risk. Women weighing less than 50 kg before delivery had 2.9 times more preterm births than women who went into labour at a normal weight and BMI . It mustAnother factor related to the childbirth complications is the per capita income, level of the country or educational level of the mother. Moliner-Sánchez et al.  stated tThe main limitation of our study would be the possible selection bias of the population, having limited the sample to pregnant women residing in the same city and belonging to the same hospital allocated to their area. However, the sociocultural level of the pregnant women in our study, obtained from the level of education of the mother, is representative of the sociocultural level of women at this time in Spain. The performance of oral examinations in different hospitals in different cities of our country, within the framework of a multicentric study, could undoubtedly increase the heterogeneity of the sample and, therefore, the external validity of the results.Another limitation is that, in our study, it was only possible to perform an oral examination at a specific time (weeks 25–36 of pregnancy), given the organizational characteristics of the health centres where the samples were collected, other examinations at different stages of the pregnancy could have enriched the results. As we know, the periodontal condition can vary or be affected throughout pregnancy by hormonal changes, suggesting that, for future research, it would be advisable to carry out several measurements during pregnancy, including puerperal ones.The relationship between periodontal disease of the pregnant woman and preterm birth and/or low birth weight has not been statistically significant in the population studied. Tobacco use during pregnancy has been associated with low birth weight in a statistically significant way. Female smokers are 4.2 times more likely to have a low-weight baby. However, the association of smoking with preterm birth has not been demonstrated. The mother’s body mass index in early pregnancy has not been significantly associated with either low birth weight or with preterm birth.Regardless of the possible association or not, oral diseases should always be prevented, especially during pregnancy. It is the responsibility of health professionals seeing pregnant patients, such as dentists, obstetricians, gynaecologists, and midwives, to provide future mothers with information about the changes that will occur in their mouth during the course of the pregnancy; furthermore, the role of the said professionals is to make available the necessary preventive measures and treatments to minimize the risk inherent in pregnancy.


To investigate and compare the safety of letrozole and natural cycles in fresh early embryo transfers.A retrospective cohort study.A large fertility treatment center.Women who underwent natural and letrozole cycles during fresh early embryo transfer at Kato Ladies Clinic between January 2008 and December 2017.None.Perinatal complications and congenital anomalies.No significant differences were observed in pregnancy complications, gestational age, birth weight, small for gestational age, large for gestational age, and congenital anomalies between the the women who underwent natural and letrozole cycles.The perinatal outcomes and congenital anomaly rates associated with letrozole and natural cycles in fresh early embryo transfers were comparable. Therefore, our data support the safe use of letrozole in fresh early embryo transfers in assisted reproductive technology. Discuss: You can discuss this article with its authors and other readers at https://www.fertstertdialog.com/posts/xfre-d-21-00212Letrozole is a type I nonsteroidal aromatase inhibitor that binds competitively to the enzyme aromatase . LetrozoMinimal ovarian stimulation with letrozole is considered a patient-friendly strategy because letrozole is a simple and inexpensive oral drug for ovarian stimulation. Recent studies have reported that letrozole-based minimal stimulation is more effective than clomiphene citrate (CC)-based minimal stimulation in patients with polycystic ovarian syndrome , 4, 5. FThe clinical records of the women who had undergone natural and letrozole cycles during SFCTs at Kato Ladies Clinic between January 2008 and December 2017 were retrospectively analyzed. The patients’ own oocytes were used during treatment. The patients who underwent preimplantation genetic diagnosis were excluded from the study. This retrospective cohort study was approved by the institutional review board of Kato Ladies Clinic . Written informed consent for the analysis of deidentified data was obtained from all the patients in the study.In the in vitro fertilization (IVF) protocol for a natural cycle, the only pharmacologic intervention was the administration of a gonadotropin-releasing hormone agonist for the induction of final oocyte maturation. Monitoring consisted of an ultrasound scan and a hormone profile; this was usually conducted on the morning of day 10 and/or 12, according to the length of the patient’s cycle. When the leading follicle reached 18 mm in diameter and the estradiol level exceeded 250 pg/mL, ovulation was triggered by the nasal administration of the gonadotropin-releasing hormone agonist buserelin . In the IVF protocol for a letrozole cycle, letrozole  was administered at a dose of 2.5 mg/day on days 3–7, and follicular development was monitored through hormone assay and ultrasonography . If foll2 at 37 °C for culturing until either conventional IVF was performed 3 hours later , with 100% humidity in a water jacket or nonhumidified incubator . The cleavage-stage embryos were graded using Veeck’s criteria 42 hours after insemination, as previously reported , generally without anesthesia or follicular flushing. The time interval between the trigger and oocyte retrieval was determined according to the degree of follicular development and hormonal status, particularly the presence of a luteinizing hormone (LH) surge. When an LH surge was not observed at the time of the decision, oocyte retrieval was performed 34–36 hours after the trigger. However, if the LH surge had already occurred at the time of the decision, the timing of oocyte retrieval was determined according to the proceeding degree of the LH surge. For example, if the LH level was 10–20 mIU/mL at the time of the decision, ovulation was triggered immediately, and the eggs were retrieved 30 hours later. Cumulus-oocyte complexes were collected, washed, and subsequently transferred to a human tubal fluid medium  with paraffin oil in 5% atmospheric COrs later  or, in crs later , 16. Allreported .At our clinic, the SFCTs were performed on day 2; however, if a patient had a schedule conflict, the SFCTs were performed on day 3. The SFCTs were performed as previously described . The cleThe primary outcomes were pregnancy outcomes, perinatal complications, and major anomalies. Pregnancy outcomes included clinical pregnancy and live birth. Perinatal complications included pregnancy complications  and neonatal outcomes .The questionnaire requested information regarding the following: date and mode of delivery, sex, birth weight, and length of the newborn(s); the presence of any birth defect or other anomaly; and pregnancy complications. Live birth was defined as delivery at ≥22 weeks of pregnancy. Preterm delivery was defined as delivery occurring at <37 weeks. Low birth weight and very low birth weight were defined as birth weights <2500 g and <1500 g, respectively. Perinatal mortality was defined as the sum of stillbirths (≥22 pregnancy weeks) and early (within 7 days) neonatal deaths. Small for gestational age and large for gestational age were defined as birth weight below the 10th percentile and above the 90th percentile, respectively, according to Japanese national reference charts for neonates . Neonata2 test. Continuous parameters were compared using a Student’s t test. Logistic regression was used to assess the contributing strength of the parameters associated with pregnancy outcomes. Odds ratios and adjusted odds ratios were reported with 95% confidence intervals for each group. Statistical significance was set at a P value of <.05.All statistical analyses were performed using JMP software . Proportion data were analyzed using a χP<.0001). The proportion of infertility causes was significantly different between the groups. The serum estradiol level on the day of maturation triggering was significantly lower in the letrozole group than in the natural group (P<.0001). However, the number of retrieved oocytes was significantly higher in the letrozole group than in the natural group (P<.0001). Embryonic quality also differed between the groups. Although the delivery rate was higher in the letrozole group than in the natural group after univariate analysis (P<.0001), no significant difference was observed between the groups after multivariate logistic regression analysis  (P = .5857).A total of 11,597 SFCTs  were performed during the study period (= .3953) . Of thesP<.0001). In contrast, body mass index and the incidence of pregnancy complications were both comparable between the groups. The cesarean section rate was lower in the letrozole group (P = .0006). Gestational age, birth length, birth weight, and infant sex were statistically comparable between the groups. The incidences of infant mortality and birth defects were comparable between the groups.The perinatal outcomes in the live-birth cycles were stratified on the basis of ovarian stimulation . Age wasCongenital anomalies were categorized into 11 types (This study found that letrozole does not increase pregnancy complications and congenital anomalies after fresh early embryo transfer, compared with natural cycles in ART. On comparing the natural and letrozole cycles in this study, participants in the letrozole group were observed to be younger. This may be because letrozole is more commonly used in patients with ovulation disorders, whereas natural cycles are occasionally followed in patients with severely depressed ovarian function, in whom ovarian stimulation is ineffective. Regarding pregnancy complications, despite the cesarean section rate being significantly higher in the natural group, no significant difference was observed in the multivariate analysis, suggesting that the difference was not due to letrozole use. There were no significant differences in congenital anomalies. Although the letrozole group exhibited higher pregnancy and delivery rates and lower miscarriage rates than the natural cycle group, the differences were not significant in multivariate analysis; therefore, letrozole cycles did not result in higher live-birth rates than natural cycles . BecauseThe strength of the present study was in its analysis of a large dataset from a single center. In addition to the large sample size, the use of letrozole, techniques of oocyte retrieval and transfer, and culture conditions were uniform in this study. Therefore, potential bias caused by differences in the detailed conditions that potentially occur in multicenter data collection was not likely.This study had certain limitations. First, its findings are not comparable to natural pregnancy. However, in a monitoring study of 10% of all deliveries in Japan, the proportion of congenital anomalies remained within a 3% range , which iNo significant differences were observed in the perinatal outcomes and the rate of congenital anomalies between letrozole and natural cycles in fresh early embryo transfers. Our findings support the safety of letrozole use in ART. A recent meta-analysis reported that the pregnancy outcome of mild IVF was similar to that of high-stimulation IVF , and the


Paralichthys olivaceus. Graded levels of BHT were added to the basal diet in increments of 0, 10, 20, 40, 80, and 160 mg BHT/kg, corresponding to 0 (BHT0), 11 (BHT11), 19 (BHT19), 35 (BHT35), 85 (BHT85), and 121 (BHT121) mg BHT/kg diets, respectively. Fish with an average weight of 77.5 ± 0.3 g (mean ± SD) were fed one of the six experimental diets in triplicate groups. Growth performance, feed utilization, and survival rate were not significantly affected by the dietary BHT levels among all experimental groups, whereas BHT concentration in the muscle tissue was found to increase in a dose-dependent manner up to 60 days of the experimental period. Thereafter, BHT accumulation in muscle tissue showed a declining trend among all treatment groups. Furthermore, the whole-body proximate composition, nonspecific immune responses, and hematological parameters (except triglycerides) were not significantly influenced by the dietary levels of BHT. Blood triglyceride content was significantly higher in fish fed the BHT-free diet compared to all other treatment groups. Thus, this study demonstrates that dietary BHT (up to 121 mg/kg) is a safe and effective antioxidant without exhibiting any adverse effects on the growth performance, body composition, and immune responses in the marine fish olive flounder, P. olivaceus.Butylated hydroxytoluene (BHT) is a commonly used antioxidant added to animal/fish feed to limit lipid autoxidation and peroxidation. Although there have been reviews and reports of BHT toxicity in animals, limited information is available with respect to the toxic effects and accumulation of BHT due to oral exposure in aquaculture species. Therefore, 120 days of feeding trial was conducted to evaluate the effects of dietary BHT on the marine fish olive flounder  In comm22:6n-3) , whereas22:6n-3 .22:6n-3) .Micropterus salmoides) [A commonly used method to improve product stability and extend the shelf-life of seafood is dietary manipulation using commercial antioxidants –13. Antilmoides) . Commerclmoides) , 23. Howlmoides) –26. Recelmoides)  reportedParalichthys olivaceus) is a commercially popular aquaculture species, particularly in the Republic of Korea, Japan, China, and other East Asian countries. Olive flounder aquaculture ranked first in terms of production volume and economic value  in the Republic of Korea [P. olivaceus.The marine fish olive flounder , 11 (BHT11), 19 (BHT19), 35 (BHT35), 85 (BHT85), and 121 (BHT121) BHT/kg. The experimental diets were prepared by mixing the dry ingredients thoroughly in an electric mixer, followed by the addition of oil and distilled water. The mixture was passed through a screw pelleting machine  to produce pellets, which were then dried for 48 h. After drying, the pellets were broken up, sieved to the required pellet size, packed, and stored at −20°C until feeding.The composition and proximate analysis of the experimental diets are presented in P. olivaceus were obtained from a private hatchery . Juveniles  were weighed and randomly stored in 300 L tanks with 35 fish per tank, with three replicate tanks per treatment. Fish were fed twice a day (09:00 and 18:00) for 120 days until apparent satiation. The feeding trial was conducted using flow-through seawater  at a flow rate of 4 L/min. Water temperature (20.7 ± 4.2°C) and dissolved oxygen levels (8.2 ± 1.3 mg/L) were maintained throughout the feeding trials. A natural photoperiod was maintained during the feeding trials, at 14 h light : 10 h dark using fluorescent lights controlled by electric timers. The fish sampling and experimental protocols were approved by the Animal Care and Use Committee of the National Institute of Fisheries Science, Republic of Korea (2021–NIFS–IACUC–7).Juvenile g for 15 min at 4°C, and plasma was collected for investigating blood chemistry and immune responses. Additionally, four fish per tank were euthanized and stored at −20°C for whole-body proximate composition analyses after the feeding trials.At the end of the feeding trial, all the fish were counted and weighed to calculate weight gain (WG), feed conversion ratio (FCR), and survival rate. To evaluate the pattern of BHT accumulation in the muscle between the dietary BHT levels throughout the feeding trial, six fish (starved for 24 h before sampling) from each treatment (two fish from each of three replicate tanks per treatment) were collected at the starting point and at the end of the 60 days and 120 days of feeding trials. The collected fish were euthanized with tricaine methanesulfonate  and dissected to sample the dorsal muscle. Muscle samples were snap-frozen in liquid nitrogen and stored at −80°C until BHT analysis. At the end of the feeding trials, blood was collected from the caudal vein of six randomly selected fish per aquarium using a 5 mL heparinized syringe. The collected blood samples were centrifuged at 1500 × BHT determination was performed on muscle samples according to the AOAC official method , which mSuperoxide dismutase (SOD), glutathione peroxidase (GPx), immunoglobulin M (IgM), and lysozyme (LZM) activity was determined using ELISA kits according to the manufacturer's protocols . Plasma aspartate transaminase (AST), glucose, total protein, total cholesterol, and triglyceride levels were determined using an automated blood analyzer , following the manufacturer's protocol.The crude protein, crude lipid, ash, and moisture content of the experimental diets and whole body were analyzed according to standard methods . BrieflyThe homogeneity of variance was tested using Levene's test. All data were subjected to one-way analysis of variance (ANOVA) using SAS version 9.3 . When a significant effect was observed, post hoc Duncan's test was performed to compare the treatment means.P. olivaceus (P > 0.05). Experimental diets were well accepted and consumed by the experimental fish, as evidenced by the excellent FCR (1.01–1.04) and survival rate (97%–100%) recorded among different dietary treatments. Average weight gain ranged from 523% to 550% among different treatment groups, without any significant differences (P < 0.05), whereas BHT intake per fish significantly increased in a dose-dependent manner and was significantly higher in the group fed the BHT121 diet, followed by the BHT85, BHT35, BHT19, BHT11, and BHT0 diets (P < 0.05).P < 0.05). Thus, the highest BHT accumulation was recorded in the fish fed the BHT121 diet followed by those fed the BHT85, BHT35, BHT19, BHT11, and BHT0 diets.Figures 121 diet was significantly higher than those of fish fed BHT85 followed by BHT35, BHT19, BHT11, and BHT0 diets (P < 0.05), respectively. However, no significant differences were detected in the muscle tissue BHT content among the groups of fish fed the BHT35, BHT19, and BHT11 diets (P > 0.05). Interestingly, after 60 days, the BHT concentrations among all treatment groups tend to gradually decline; however, at the end of 120 days, the muscle BHT content of the flounders fed the BHT121 diet was significantly higher than those of fish fed other experimental diets (P < 0.05).In contrast, the effects of culture duration on muscle-specific BHT accumulation were clearly observed . At the P. olivaceus (P > 0.05).P > 0.05) except for decreased serum triglycerides in P. olivaceus. The triglyceride content of the fish fed the BHT11, BHT19, BHT85, and BHT121 diets was significantly lower than that of fish fed the BHT0 diet (P < 0.05). However, the triglyceride content of the BHT35 groups was not significantly different from that of the other experimental groups (P > 0.05). Although numerical differences were recorded in the AST, glucose, total protein, and cholesterol content among the different treatment groups, no clear trend could be observed (P > 0.05).P > 0.05).The effects of different levels of BHT-supplemented diets on the whole-body proximate composition of the olive founders are shown in The growing safety concerns associated with seafood production and consumption require a clear understanding of both nutrients and contaminants throughout the production chain. In recent years, the production of consumer-friendly seafood using feeds that are low in contaminants and antioxidants has received considerable attention. The synthetic antioxidant BHT, through the carry-over process from fish feed, can have toxic and negative health impacts on both fish and consumers . HoweverPenaeus monodon, reared at various temperatures for 60 days. These authors observed that dietary BHT resulted in a substantial improvement in the growth of juvenile shrimp only after 45 days, although the number of treatments was limited in this study. In contrast, in a more recent study, Yu et al. [Micropterus salmoides) fed various levels of BHT-supplemented diets for 10 weeks. Similarly, in the present study, no evidence was found suggesting any positive/negative impact of BHT inclusion up to 121 mg/kg (BHT121) on the growth performance of P. olivaceus reared for 120 days.As evidenced by the excellent survival rate (97%–100%), growth performance, and FCR, the experimental diets were well accepted and consumed by the fish in all treatment groups . Studiesu et al.  reportedP. olivaceus.Interestingly, published reports also suggest weight loss in rats fed BHT-supplemented diets at 125–150 mg/kg body weight . SimilarThe residue levels of synthetic antioxidants in food products, including seafood, have become a matter of serious concern. Despite the urgency driven by the growing awareness and interest in healthy human food, only limited published data are available on the residue levels of synthetic antioxidants in commercial fish fillets . A previ0) diet treatment. Although 1,000–4,000 mg/kg of BHT is typically included in fishmeal production to prevent spontaneous combustion during overseas transport and storage [0 treatment group likely reflects accumulation during the 10-day acclimation period, when all the fish were fed the BHT35 diet. Overall, BHT accumulated in the muscle tissues of P. olivaceus in a dose-dependent manner during the first 60 days of the culture period and afterwards gradually declined.Interestingly, BHT accumulation was also observed in the BHT-free . Similarly, Yu et al. [Nonspecific immunity is the major defense system in fish and shellfish and plays a vital role in acquiring immune responses and homeostasis through a system of receptor proteins. In aquaculture, optimized antioxidants and immunity are important for combating stress, maintaining health, and ensuring optimal survival and growth , 40. Amou et al.  reportedP. olivaceus were not significantly affected by the dietary BHT treatments. In comparison, triglyceride content tended to decrease as the BHT concentration increased and was lowest among the BHT121 treatment group. Decreasing plasma triglyceride levels with a corresponding increase in BHT levels could be a potential indicator of enhanced lipid metabolism [Hematological parameters, such as triglycerides, total protein, AST, cholesterol, and glucose, are known to be promising indicators of animal health , 46, 47.tabolism . Indeed,tabolism . It is wtabolism . Likewistabolism . A possitabolism , 32, 33.tabolism . Hence, tabolism . HoweverP. olivaceus up to 121 mg/kg was found to be safe and effective with no beneficial/adverse effects on the fish growth, nonspecific immunity, and whole-body nutrient profiles. However, observations for the hematological characteristics showed an adverse effect on the triglyceride levels with a corresponding increase in the dietary BHT levels. Nevertheless, the observation of BHT accumulation in the fish muscle tissues during the first 60 days of exposure and its subsequent gradual decline warrants further examination using long-term farm trials for P. olivaceus and other important aquaculture species.The inclusion of BHT in the diet of