Aims This work aimed to study consequences of medical interventions in connection with birth on infant pre-feeding and feeding behaviors and on maternal oxytocin levels in connection with a breastfeed 2 days later.Materials and Methods Mothers and their full-term newborns (n = 41) were videotaped during a breastfeed 2 days after birth. Duration and quality of rooting [Infant Breastfeeding Assessment Tool (IBFAT)] were assessed. Maternal blood samples were collected, oxytocin levels were analyzed, and mean oxytocin level and variance were calculated. Data on medical interventions during birth, number of breastfeedings, and infant weight loss since birth were recorded. Data were analyzed using logistic regression models.Results The duration of infant rooting was significantly shorter when the mother had received epidural analgesia. The shorter the duration of infant rooting, the more often infants had breastfed and the greater was the infant weight loss since birth. Mothers with epidural analgesia with oxytocin had the lowest oxytocin mean levels in connection with a breastfeed. Oxytocin variance correlated positively with quality of rooting and correlated negatively with infant weight loss. In the control group alone, we found similar patterns of associations with oxytocin levels.Conclusion Epidural analgesia and epidural analgesia with oxytocin infusion in connection with birth negatively influenced infant rooting behavior and maternal mean oxytocin levels, respectively. Oxytocin infusion alone was without effect. The data also suggest that infants who suck well stimulate oxytocin release more efficiently, as expressed by a high oxytocin variance, leading to a better stimulation of milk production and consequently to a reduced infant weight loss 2 days after birth. The When a healthy full-term newborn infant is placed in uninterrupted contact SSC with his/her mother immediately after normal and non-medicated birth, the newborn exhibits an organized pre-breastfeeding behavioral pattern. The infant starts to suck the breast at about 1 h of age and falls asleep at about 2 h of age .Rooting is one of the most well-known and well-defined pre-feeding behaviors of the newborn. During rooting, the infant lifts his/her head and turns the head from side to side with concomitant opening of the mouth to prepare for sucking . RootingA previous study has demonstrated that infant rooting behaviors most likely predict the ability to express the infant’s need for food, i.e., to breastfeed. If the infant does not root or roots to a lesser extent, (breast)feeding ability is depressed. Thus, rooting is an internal feeding cue from the newborn, and for the mother, rooting behavior is a clear signal that the infant wants to breastfeed . Thus, iOxytocin is a peptide molecule which is produced in the supraoptic and paraventricular nuclei (SON and PVN) of the hypothalamus and is transported to the posterior pituitary and released into the circulation. The milk ejection reflex is stimulated when the infant starts to suck the breast . SuckingIn a recent study by our group, pre-feeding and sucking behaviors of the full-term newborn to unmedicated mothers were studied in connection with a breastfeed 2 days after birth . It was However, pre-feeding behaviors occurred in the same order as immediately after birth: rooting, hand-to-mouth movements, licking of the nipple, and hand-to-breast-to-mouth movements, where rooting was the most prominent behavior. Furthermore, low infant age and high weight loss since birth were related to a long duration of rooting, suggesting the existence of a physiological mechanism aimed at ascertaining adequate food intake .The use of medical interventions has become more common during childbirth over the last decades. Epidural analgesia (EDA) is the most common pharmacological pain relief during labor in the Western world. For example, 62% of primiparous women in Sweden receive EDA at some stage of labor . EvidencInfusions of synthetic oxytocin are widely used as a medical intervention in maternity wards to induce or augment labor, and oxytocin is also recommended to prevent or treat postpartum bleeding .In a study by Hence, in previous studies, possible effects of EDA and oxytocin infusion have not been studied separately, and there are no studies showing that oxytocin given alone has a negative impact on infant behavior.Additionally, medical interventions in connection with birth such as cesarean section and EDA together with oxytocin infusion negatively impact oxytocin levels 2 days after birth during breastfeeding .In light of the findings above, our aims in the present study were threefold:1)with or without oxytocin administered to the mother during childbirth affected pre-feeding behaviors of the newborn 2 days after birth.To explore whether intravenous (iv) infusion or intramuscular (im) injection of exogenous oxytocin or EDA 2)To explore if medical interventions in connection with birth and pre-feeding and sucking behaviors of the infant influence maternal oxytocin release in connection with a breastfeeding 2 days after birth.3)To investigate whether infant weight loss and number of breastfeeding since birth influence the variables described above.This study is part of a larger study conducted at a postnatal ward in Stockholm, Sweden . SwedishIn the larger study, 72 mothers were included. However, in the present study, 41 mother–infant dyads participated (21 boys and 20 girls). The reasons for not being included were as follows: 16 mothers did not want to be video filmed, one infant had a fracture of the clavicle, and 14 films were of a quality that did not allow detailed assessment of behaviors of the newborn.without OT iv group) and 10 mothers had received EDA with oxytocin infusion (the EDA with OT iv group).All women had a spontaneous, vaginal birth and had skin-to-skin contact with their infants immediately after birth. All newborns had breastfed after birth. The mothers had been consecutively recruited to the study and were grouped based on which medical interventions they had received during labor. Thirteen mothers had received no medical intervention during labor, the control group (CTRL). Five mothers had received intravenous oxytocin infusion alone, the oxytocin group (OT iv). Eight women has received oxytocin as an intramuscular injection after birth, the OT im group (OT im). In total, 15 mothers had received EDA: five of those had received EDA alone (the EDA n = 15). The oxytocin infusion ampullae, containing 10 IU (16.6 μg) of oxytocin/ml  were diluted in 500 ml of Ringer’s acetate solution , giving rise to a concentration of (20 mIU/ml or 33.3 ng/ml).If inertia was diagnosed during labor, oxytocin was administered intravenously (25–Q75) amount of oxytocin given to mothers during birth was 1.86 (1.145–5.046) μg in the OT iv group and 4.16 (1.487–6.308) μg in the EDA with OT iv group.The median  im after birth to prevent postpartum bleeding. During the study period, midwives were instructed not to administer oxytocin to the women fulfilling the inclusion criteria. However, some midwives did not comply with this instruction, and therefore, some mothers received 10 IE oxytocin im postpartum. These mothers constitute the OT im group.®, AstraZeneca, Södertälje, Sweden) in combination with the pain-relieving opiate sufentanil . The median (Q25–Q75) duration (hours:minutes) of infusion of EDA was 2:59 (1:40–4:33) in the EDA without OT iv group and 4:23 (2:32–6:27) in the EDA with OT group. The median dose of bupivacaine was 17.5 (15.0–25.0) mg in the EDA without OT iv group and 17.5 (17.5–40.6) mg in the EDA with OT iv group, and the corresponding dose of sufentanil was 10.0 (10.0–15.0) and 10.0 (10.0–25.0) μg.When mothers were in need of pain relief, EDA was given. EDA consists of the local anesthetic bupivacaine , blind to the mothers’ clinical and sociodemographic information, performed all assessments of infant breastfeeding sessions.Video films were downloaded into the INTERACT software, version 9 Before sucking, newborns exhibited a number of pre-feeding behaviors . The duration of the first sucking period  was assessed. These behaviors are described in The Infant Breastfeeding Assessment Tool (IBFAT), a validated and well-established study protocol to assess infant feeding competence , was useInter-observer reliability was tested for the two instruments by two independent observers (YT and ABRA) who assessed 10% of the video films. Interrater reliability was high across the assessments (82–96% for the pre-feeding variables and 100% for the IBFAT items).TM Oxytocin Enzyme Immunoassay Kit according to the manufacturer’s instructions  . Plasma samples were diluted five times in the assay buffer before analysis of oxytocin. Standards and controls were included on each plate as recommended by the manufacturers. The washing procedure was performed using an Anthos Fluido microplate washer , and the absorbance was read using a Multiskan EX microplate photometer . The color development of the samples was read at 405 nm. Background correction was measured at 580 nm. Ascent software  was used for creation of standard curves, curve fitting, and calculation of concentrations.Blood samples were collected from an intravenous cannula inserted into the cubital vein in connection with the breastfeeding experiment performed 24–48 h after birth. The first blood sample was drawn immediately after the newborn started to suck the breast and was considered as the basal sample (sample 0). Then 15 samples were taken with 30-s intervals during the first 7.5 min, and thereafter, four samples were collected at 10, 20, 30, and 60 min after the start of sucking . The samples were analyzed for oxytocin using the Correlate-EIAIn the present study, we used ELISA as a method of analysis, without previous extraction of the samples. Much higher basal levels are detected using ELISA without previous extraction of the samples compared with using RIA. Although there is a difference in the size of basal oxytocin levels, the pattern of oxytocin release did not differ from the ones observed in studies in which RIA was used . Using bDescriptive statistics were used to summarize the maternal and infant background characteristics and breastfeeding variables including pre-feeding behaviors and IBFAT subscale and total scores. The infant behavior was observed during 10-s periods for the last 60 s before sucking. The sum of the observations for each period was used for further calculation.25–Q75) or as frequencies and percentages (%). Mean oxytocin levels (20 samples) were presented as means (m) and standard errors (±SE). Oxytocin variance was assessed as the square of the standard deviation and was calculated for each mother (16 samples). The oxytocin variance is presented as means (±SE) and was used for further analysis of the oxytocin pattern.Data in general were described by medians and interquartile distances . The distribution of data was assessed before analysis. Duration of rooting had a Poisson distribution. Mean oxytocin levels (0–60 min) had a skewed distribution and was therefore log-transformed. Oxytocin variance had a normal distribution.p ≤ 0.05 was considered significant.We performed logistic regression analyses using a generalized linear model (Proc genmod) for all variables except IBFAT rooting, where an ordinal logistic regression (Proc logistic) was used. Parameters that were tested are presented in the section “Results.” A probability value of The Ethics Committee at Karolinska Institutet, Stockholm, Sweden, had approved the study. All women provided written, informed consent.Maternal and infant background characteristics and observational data such as the number of breastfeeding and infant weight loss since birth and infant age at the observed breastfeeding day 2 are given in without OT, EDA with OT, and CTRL) in The total duration of pre-feeding behaviors and the first sucking period was recorded. In addition, the duration of individual subcomponents of the pre-feeding behaviors , during the last 60 s before the start of sucking, was recorded. Values are presented for all four intervention groups and the control group  in without OT group. The median of the subscale rooting was the lowest in the EDA without OT iv and in the EDA with OT iv groups  is presented as medians and , and the percentage of weight loss in the infants (covariate) from birth until the observed breastfeeding 2 days after birth was investigated using a generalized linear model.p < 0.0001, χ2 = 58.91, DF = 4). Post hoc tests revealed that infants of mothers who were not exposed to any medical intervention (CTRL) showed a significantly longer duration of rooting than the infants in the four intervention groups   . Furtherth OT iv . The shop < 0.0001, χ2 = 67.11); infants who had had seven or less breastfeeding sessions before the observed breastfeeding (n = 23) showed a significantly longer duration of rooting [median (Q25–Q75): 24.04 (6.12–46.76) seconds] compared to infants with eight or more breastfeeding sessions (n = 16) [median (Q25–Q75): 13.02  seconds]. In other words, the more breastfeeding sessions the infants had experienced before the observed breastfeeding 2 days after birth, the shorter the duration of rooting.In addition, there was a significant effect of number of breastfeedings on the duration of rooting before the start of sucking  on the duration of rooting before the start of sucking. The maximum likelihood estimate for percentage of weight loss was negative , meaning that the higher the percentage of weight loss in the infants, the shorter the duration of rooting.There was also a significant effect of percentage of weight loss since birth  and the different medical interventions the mothers had received during birth, the number of breastfeeding (≤7 and ≥8), and the percentage of weight loss in the infants (covariate) from birth until the observed breastfeeding 2 days after birth was investigated using ordinal logistic regression.p = 0.106, χ2 = 7.64) or the number of breastfeeding after birth .There was no significant association between the scores of IBFAT rooting and the medical interventions the mothers had received . Odds ratio (OR) estimates showed that infants born to mothers who had received EDA with OT iv had a lower IBFAT rooting scores than controls .A without OT iv group showed the shortest duration of rooting. . By contrast, administration of oxytocin either iv or im did not influence the infant’s rooting behavior.In conclusion, these two analyses above show that the medical interventions received by the mother in connection with birth influenced the duration of the infant’s rooting behavior preceding sucking . The EDA In addition, the number of breastfeedings before the observation, performed 2 days after birth, influenced the duration of rooting behavior; i.e., the more breastfeeding after birth, the shorter the duration of rooting. Additionally, the higher the weight loss in the infants since birth, the shorter the duration of rooting.Infants’ rooting behavior is an essential component of infants’ pre-feeding behaviors and thereby associated with initiation of breastfeeding, which is known to trigger maternal oxytocin release. It was therefore of interest to investigate if the duration or quality of infant’s pre-feeding behaviors is linked to maternal oxytocin levels in connection with breastfeeding. It was also of interest to investigate a possible relationship between the use of medical interventions during birth, such as administration of exogenous oxytocin or of EDA, as well as the number of breastfeedings and the weight loss of the infant since birth.We used two types of oxytocin measures that express different characteristics of the oxytocin profile. Oxytocin mean levels (0–60 min) to a large extent reflect the maternal individual characteristics, whereas oxytocin variance (0–7.5 min) to a large extent reflects infant sucking activity and capability.Therefore, in the following analyses, we explored whether medical interventions administered to the mother during birth, duration (covariate) or quality of infant rooting, duration of sucking (covariate), the number of breastfeedings (≤ 7 and ≥ 8), and percentage of weight loss (covariate) were associated with maternal mean oxytocin levels or oxytocin variance during the observed breastfeeding 2 days after birth. We used a generalized linear model.p = 0.02) , OT im (p < 0.05), and EDA without OT iv (p < 0.001)—or in control mothers, CTRL (p < 0.05). Mean oxytocin levels (0–60 min) in the different groups in connection with a breastfeeding 2 days after birth are shown in The statistical analysis showed that maternal mean levels of oxytocin in connection with a breastfeeding 2 days after birth were significantly associated with the medical interventions the mothers had received during birth ( = 0.02) . The meap = 0.03) (SE = 0.0051), indicating that the longer the duration of sucking, the higher the mean oxytocin levels.Oxytocin levels in connection with the observed breastfeeding 2 days after birth were significantly associated with the duration of sucking ( = 0.03) . This asThere were no significant associations between mean oxytocin levels and the number of breastfeeding since birth, IBFAT rooting score, and percentage of infant weight loss .p = 0.02). The association was negative , indicating the higher the percentage of weight loss in the infants, the lower the variance of maternal oxytocin levels (0–7.5 min).There was a significant association between variance of maternal oxytocin levels and percentage of weight loss in the infants since birth  During Breastfeeding” and “Variance of Maternal Oxytocin Levels (0–7.5 min) During Breastfeeding” above was performed in the control group alone.p = 0.0001) (The number of breastfeeding since birth in control mothers was significantly associated with mean oxytocin levels ( 0.0001) . Mean oxp = 0.0001) (SE = 0.106), meaning that the higher the percentage of infant weight loss, the lower the oxytocin levels.There was also a significant association between percentage of infant weight loss since birth and mean oxytocin ( 0.0001) . The assThere were no significant associations between mean oxytocin levels and IBFAT rooting score and duration of sucking .p = 0.012) (SE = 40.15), meaning that the higher the percentage of weight loss, the lower the variance of oxytocin.The variance of oxytocin in control mothers was significantly associated with the percentage of weight loss since birth in the infants (= 0.012) . The assThere was no significant association between variance of oxytocin levels and number of breastfeeding, IBFAT rooting score, and duration of sucking .In the present study, the duration of some pre-feeding behaviors during the last minute before the start of sucking and IBFAT scores, a qualitative measure of infant breastfeeding performance, were assessed in connection with a breastfeeding 2 days after birth.with infusion of oxytocin administered to the mothers in connection with labor and birth. By contrast, no effect on rooting was observed by administration of oxytocin iv or im. In addition, the more often the infants had breastfed and the greater their weight loss since birth, the shorter the duration of infant rooting.Regression analyses revealed that duration and quality of rooting were negatively influenced by both EDA alone and by EDA together We also assessed maternal oxytocin levels  in connection with the same breastfeeding.with oxytocin infusion had the lowest mean oxytocin levels. The duration of sucking was positively associated with mean oxytocin levels. Medical interventions did not influence oxytocin variance, but the variance was lower the higher the weight loss of the infants.Regression analysis showed that there was a significant influence by medical interventions during birth on mean oxytocin levels in connection with breastfeeding. Mothers who had received EDA When similar analyses regarding oxytocin levels were performed in the control mothers alone, i.e., in those mothers who had not received any medical intervention during birth, some new associations were found; low mean oxytocin levels were associated with a low number of breastfeedings since birth and were also associated with greater infant weight loss since birth. Oxytocin variance was lower the greater the infant weight loss since birth.without oxytocin administration displayed significantly less rooting behavior during the 60 s preceding the breastfeeding session than those who had not received EDA or EDA with oxytocin. In addition, the quality of rooting was significantly lower in the group of infants whose mothers had received EDA with oxytocin.Infants of mothers who had received EDA We observed a shortened period of rooting on day 2 after birth, indicating that rooting had been depressed since birth. The fact that the rooting period was shorter may be one of the reasons for the lower weight gain observed in infants whose mothers had received EDA in connection with birth.The finding of an impaired infant rooting behavior in the present study is in accordance with data from a previous study, in which infants to mothers who had received mepivacaine or bupivacaine, e.g., in connection with administration of EDA, displayed a deranged interactive behavior with their mother after birth . This efAlternatively, the effects observed on the rooting behavior of the newborn are indirect and operate through a changed physiology or through the behavior of the mother. This assumption is supported by the fact that skin temperature did not increase in the infants of the present study in connection with breastfeeding , which uIt has been suggested that oxytocin administered to the mothers in connection with birth would influence the newborn’s behavior in a negative way and that administration of oxytocin would negatively impact the development of the infants’ sucking behavior . These snot received any medical interventions in connection with birth, and rooting duration was longer the younger the infants were and the more weight they had lost 2 days after birth. We interpreted this finding as an expression of a physiological adaptation to increase food intake and thereby weight gain, which would be of critical importance not only in young infants but also in those who have been exposed to a substantial loss of weight. As mentioned above, the findings of the present study show an inverse relationship between rooting and weight loss after birth. The finding in this study suggests that the physiological adaptation, allowing compensation for high weight loss, was lost or disturbed when studied in the whole group of mothers. It is likely that the pronounced decrease of the duration of rooting caused by EDA plays a central role in the inversion of the relationship between duration of rooting and size of infant weight loss since birth which was found in the whole group.We also found a negative correlation between duration of rooting and weight loss of the infant since birth, i.e., the more weight the infant had lost, the less rooting they performed. These results are in contrast to previous findings based on this study . The stuBoth mean oxytocin levels and oxytocin variance were used when analyzing the data of the present study, since it can be assumed that these two measures depict partly different aspects of the oxytocin release pattern in connection with sucking. Oxytocin levels rise almost immediately in response to sucking/breastfeeding and exhibit a peak-shaped response during 20 min, and then oxytocin levels return to basal levels . Mean oxMaternal mean oxytocin levels were significantly lower in mothers who had received both EDA and oxytocin iv, when compared to the effect observed in response to either of the treatments alone. In addition, it was found that oxytocin levels in the control group and in the group who had received oxytocin im were significantly higher than in the group of mothers who had received epidural and oxytocin.These data support but extend results from a previous analysis of the same data set, in which a significant difference regarding maternal mean oxytocin levels was demonstrated between the group of mothers who had received EDA and those who had received EDA and oxytocin iv .with oxytocin may seem difficult to explain. However, there is reason to believe that the combination of oxytocin and EDA interferes with feedback mechanisms, such as the Fergusson reflex and the sympathetic fibers mediating pain, in connection with birth, thereby establishing the lower oxytocin levels. As this group of mothers also has signs of higher stress levels, e.g., higher levels of ACTH and cortisol, the lower oxytocin levels may be an expression of higher stress levels in these women  was negatively influenced by administration of EDA, Oxytocin alone given as an intravenous infusion during labor or as an intramuscular injection postpartum to the mother did not exert a negative influence on duration of rooting or quality of rooting in the infant or on maternal oxytocin levels or variance. In fact, a slight positive effect was observed on duration of rooting in the infants and on maternal oxytocin levels in mothers who had received intravenous infusion of oxytocin during birth.A short duration of rooting and a low variance of oxytocin, presumably a consequence of low infant sucking activity, are linked to a greater infant weight loss 2 days after birth. These data suggest that reduced infant pre-feeding and sucking behaviors result in a lower milk production due to an insufficient stimulation of oxytocin and prolactin release .with or without oxytocin infusion in connection with birth may decrease the release of maternal oxytocin and thereby disturb the milk ejection reflex. In addition, infants’ feeding-associated rooting reflex was decreased 2 days after birth if the mother had received EDA in connection with birth. Therefore, EDA and the combination of EDA together with infusion of oxytocin may influence breastfeeding success and consequently infant’s weight gain.Taken together, EDA In the Swedish setting, it would have been unethical to randomize women to medical interventions, e.g., administration of EDA, and/or to oxytocin infusion. In the present study, mothers were consecutively recruited, capturing the clinical flow of appearance/administration of the medical interventions. Our sample size is small, but the rigorous selection of participants and the meticulous data collection make this study unique and make a significant contribution to this field of research. Our strict inclusion criteria enabled us to include a homogenous group of healthy primiparous mothers who had not experienced any complications during or after birth and who gave birth in a labor ward admitting only women expecting a normal physiological birth. Furthermore, the research group has a long experience of conducting similar studies, and the experimental design is well validated . The samwith or without oxytocin infusion, may influence breastfeeding success and infant weight gain. These data suggest that it is of clinical importance to consider the effects of various medical interventions in regard to breastfeeding success.The present data demonstrate that EDA during birth exerts a negative effect on infant rooting and maternal oxytocin release in connection with breastfeeding. The data show a clear effect of infants’ sucking behavior on maternal oxytocin levels, which has not been demonstrated before. The effect caused by medical interventions, EDA wibke.jonas@ki.se.The datasets presented in this article are not readily available because our videofilms cannot be anonymized and thus, we cannot share the data. Requests to access the data should be directed to WJ, The local ethics committee at Karolinska Institutet, Stockholm, Sweden, had reviewed and approved the study. All study participants provided written, informed consent.WJ performed the data collection. YT performed the behavior assessments with supervision of A-BR-A, EN, and LL. WJ, EN, and LL performed the data analysis. All authors contributed to the study conception and design, discussed and wrote the manuscript, and read and approved the final manuscript.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.


The risk of neurodevelopmental disorders in low birth weight (LBW) infants has gained recognition but remains debatable. We investigated the risk of attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) in school-aged children according to their birth weight. We conducted a retrospective cohort study using the Korean National Health Insurance claims data of 2,143,652 children who were born between 2008 and 2012. Gestational age of infants was not available; thus, outcomes were not adjusted with it. Not only infants with birth weights of < 1.5 kg, but also 2.0–2.4 kg and 1.5–1.9 kg were associated with having ADHD; odds ratio (OR), 1.41 , and 1.49 (95% CI 1.33–1.66), respectively. The OR in infants with birth weights of 2.0–2.4 kg and 1.5–1.9 kg was 1.91 (95% CI 1.79–2.05) and 3.25 (95% CI 2.95–3.59), respectively, indicating increased odds of having ASD. Subgroup analysis for children without perinatal diseases showed similar results. In this national cohort, infants with birth weights of < 2.5 kg were associated with ADHD and ASD, regardless of perinatal history. Children born with LBW need detailed clinical follow-up. In the Republic of Korea (Korea), in 2019, the total fertility rate dropped to a low record of 0.92. However, the proportion of LBW infants has increased from 3.8 to 6.6% of the total live births in the last two decades. Importantly, those with birth weights between 1.5 and 2.4 kg accounted for 5.8% of the total live births in 20193.Birth weight is an important health indicator of optimal child health and development. Low birth weight  is often associated with a higher risk of neonatal mortality and increased utilization of healthcare services during the first year of life6. ADHD is one of the most common neurodevelopmental disorders in childhood. Children and adolescents with ADHD have inattention and/or hyperactivity-impulsivity patterns that affect functions and development. The estimated prevalence of ADHD ranged from 3.4% to 5.3% in children and adolescents worldwide8. ASD is characterized by persistent deficits in social communication and interaction and the presence of restricted and repetitive behaviors9. Additionally, ASD is associated with considerable lifetime costs not only to the individual and their family but also to the society10. Although the results of the meta-analyses indicated that LBW or preterm infants had an increased ADHD or ASD risk, most studies have focused on very low birth weight infants  or very preterm infants 6. There are ongoing debates on the developmental and behavioral disorders of infants with birth weights between 1.5 and 2.4 kg or late preterm infants 12. Because of the increasing prevalence of LBW infants, it is necessary to evaluate the neurodevelopmental prognosis of these children.LBW infants may experience behavioral and emotional problems. Previous studies have revealed LBW to be associated with lower academic achievement, lower intelligence quotient, and developmental and behavioral disorders, such as attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder (ASD)This study aimed to address this knowledge gap by conducting a nationwide retrospective cohort study in Korea using the National Health Insurance Service (NHIS) claims data. We assessed the association between birth weight and two neurodevelopmental disorders (ADHD and ASD); especially, those whose birth weight ranged from 1.5 to 2.4 kg were investigated. We also aimed to evaluate the outcomes of these children according to their congenital or perinatal medical history.A total of 2,359,324 live births were identified between 2008 and 2012 through the database in Korea. Among these data, children who died before 2018, had missing birth weight records, missing income data information, and had a birth weight of less than 0.4 kg were excluded. Thus, this study evaluated 2,143,652 live birth infants Fig. . As we wTable Among children who were born between 2008 and 2010, 2.2% were diagnosed with ADHD  and approximately 50% were prescribed medication Table . SubgrouApproximately 0.7% of children who were born between 2008 and 2012 were diagnosed with ASD and LBW infants were more likely to be diagnosed with ASD earlier than were NBW infants Table . Among cThis study assessed the association between birth weight and the diagnosis of ADHD and ASD using a large national cohort. VLBW infants and those with birth weights of 1.5–2.4 kg had increased odds of having ADHD and ASD, as compared with NBW. Birth weights over 4.0 kg were associated with having these disorders, but were not statistically significant after adjusting for confounding factors. We analyzed children without congenital or perinatal diseases, thereby controlling for disease history, and obtained higher odds in the lower birth weight groups.13. In a Norwegian study of 903,402 infants who were born between 1967 and 1983, researchers reported a nonsignificant higher risk  of ASD among late preterm infants . The study showed that late preterm infants had increased risks of developing psychological, behavioral, and emotional disorders but it was not limited to ADHD11. A previous case–control study conducted in Finland found that infants with LBW (1.5–2.5 kg) had an increased risk of autism  and pervasive developmental disorders , but there was no association with Asperger syndrome 14. In the current study, we found that infants with birth weights of 2.0–2.4 kg and 1.5–1.9 kg were associated with a higher OR of having ADHD  and ASD . The trends were similar in the subgroup analyses for children without congenital or perinatal diseases. Furthermore, infants with birth weights over 4.0 kg had increased risks of ADHD and ASD but were not statistically significant after adjusting for confounding factors. These results are consistent with previous findings that neurodevelopmental disorders regarding with perinatal complications or socioeconomic status regarding with the gestational overgrowth16.A previous large national cohort study in Sweden reported that gestational age was independent of the covariates and familial factors for being diagnosed with ADHD and autism. However, the study had limited information about congenital or perinatal diseases19. Among these regions, the prefrontal cortex is known to be important for regulating attention, behavior, and emotion and has been found to contribute to ADHD20. The prefrontal cortex is often called a “late developing” region of the brain. Prefrontal development is affected by prematurity and social environment, such as exposure to maltreatment or poverty during childhood that results in symptoms21. The amygdala is one of the most important brain regions involved in the pathogenesis of ASD. The amygdala experiences the earliest prenatal structural and functional growth in the brain. Therefore, the region is vulnerable to perinatal diseases or extrauterine environments that LBW infants may encounter during the early neonatal period25. The difference of impact of birth weight between ADHD and ASD in the present study can be attributed to the differences in the period of development of these brain regions.Compared with ADHD, the OR according to birth weight was greater in ASD. The pathogenesis of ADHD and ASD are multifactorial and include genetic susceptibility and intrauterine or postnatal environment. Brain regions that play key roles are different in these disorders27. Establishing a proper screening system is important to identify ADHD and ASD early and provide appropriate intervention 29. The American Academy of Pediatrics (AAP) recommends screening all children for ASD at 18 and 24 months of age during their primary care visits using a combination of general developmental screening tools and standardized autism-specific screening tests30. However, while the AAP does not recommend universal screening for ADHD, it recommends pediatricians or primary care clinicians to screen for ADHD when academic or behavioral problems and ADHD symptoms exist in children from 4 to 18 years of age31. In Korea, physicians probe for ASD with two or three questions during the National Health Screening Program for Infants and Children (NHSPIC); nevertheless, no validated universal ASD-specific screening program exists32. Introducing an ASD screening program suitable for the health system of each country is necessary, and establishing a universal ASD-specific program should be considered, at least for high-risk groups, such as those with LBW. As regards ADHD, it is important to inform the caregiver or educational institution of the ADHD symptoms so that a referral can be made.This study showed that children with lower birth weight were diagnosed with ASD earlier. VLBW infants are usually encouraged to regularly visit outpatient clinics to monitor long-term follow-up outcomes. This routine appears to affect earlier diagnosis in the VLBW group. In contrast, infants with birth weights of greater than 2.0 kg are diagnosed with ASD 1–2 years later than the average age of diagnosis. They could be a relatively less investigated group than those with VLBW, and the risk of neurodevelopmental disorders in these children might have been overlooked. Previous studies have suggested that early intervention can improve the outcomes of children with ADHD and ASDThe major strength of present study lies in the fact that more robust estimates could be made based on the nationwide live-born data from the NHIS database. This increases the generalizability of the results and may minimize bias. Furthermore, this study was not limited to a single birth weight category but assessed all newborns; hence, we could explore the possible association between neurodevelopmental outcomes and birth weight category. Previous studies have seldom analyzed birth weights other than 2.0–2.4 kg or greater than 4.0 kg. In addition, we analyzed two representative neurodevelopmental disorders and compared their association with birth weight. The results were controlled for congenital or perinatal diseases and income level of the family; furthermore, subgroup analysis was performed for children without associated diseases.33. Establishing a national birth cohort that can link the family health data with the infants’ long-term outcomes could help assess and manage the health of high-risk infants. Finally, this study revealed the association between birth weight and neurodevelopmental disorders, but not the causality. However, the factors identified in this study may help identify the pathogenesis of these disorders.This study had some limitations. First, we did not have access to gestational age data, which was one of the most important prognostic factors, and this hindered us from assessing the associations of small for gestational age and neurodevelopmental disorders. The major reason is that the NHIS does not provide the gestational age in order to protect personal information. We considered using the codes from the International Classification of Diseases 10th revision (ICD-10) for preterm births, but the number of infants who had those codes was only half of the number of preterm infants in the Korean birth statistics. Moreover, the codes were divided into two or three groups based on the gestational age of 28 (until 2010) or 32 weeks (until 2015) in Korea. Therefore, it was impossible to assess the prognosis of late preterm infants who corresponded to the group of interest in this study with the codes. Until now, utilizing birth weight data in the NHSPIC has been the best method to access birth information in Korea, and constant efforts are required to change the policy such that the NHIS can provide more birth information. Second, we could not obtain data on the family’s medical history, such as maternal pregnancy complications or parents’ and siblings’ mental health history. With family history, it would be possible to assess hereditary aspects of neurodevelopmental disordersDespite the improvements in neonatal care, LBW  infants born between 2008 and 2012 still had higher ADHD and ASD risk than those with NBW. In particular, children born with LBW without congenital or perinatal history had similar results. Physicians in tertiary hospitals as well as those in primary care clinics who often follow-up children born with LBW should be aware of this. Additionally, further studies on detailed clinical follow-up and screening for neurodevelopmental disorders of LBW are required.32. By 2019, 94.6% of children underwent a check-up at least once in their lifetime34. During their check-ups, parents reported the children’s birth weight as indicated in the birth certificate issued by the birth medical institutions. A study introduced the NHIS-NHSPIC cohort with children born in 2008 and 2009, and we extended the cohort to children born in 201235. Several studies were conducted using the Korean NHIS cohorts and recently, studies regarding long-term outcomes of newborns using the NHIS database were published39.Korea achieved universal health coverage in 1989, and all national health insurance and medical aid claims data for insurance-covered medical services that all medical institutions provide are managed in a single centralized database. This database contains information on demographics, healthcare utilization, expenditures, and diagnoses based on the ICD-10. Upon researchers request, the NHIS provide the integrated data with NHSPIC results: birth weight, weight, height, and developmental assessment at screening. The NHSPIC began in November 2007. The program targeted infants and children aged less than 6 years; their growth and development are monitored seven times overall40. The National Cancer Center IRB reviewed and exempted this study (NCC2019-0292) from the requirement of obtaining informed consent because the NHIS data are anonymized. We were granted access to all data of children born between 2008 and 2017.This study was designed and performed in accordance with the principles of the Declaration of Helsinki. The institutional review board (IRB) approval statement and the research plan summary were submitted to the NHIS website to gain access to the database. These were approved by the review committee that decides on the provision and use of national health information data to assigned research institutions41. We excluded those who died before 2018 or those without the NHSPIC or income data. Moreover, we excluded those with birth weights less than 0.4 kg, considering that neonatal resuscitation was withheld for them, and assumed that the birth weight was recorded incorrectly42.This study included all live births between 2008 and 2012; however, considering the average age at ADHD diagnosis, analyses for ADHD were performed for children born between 2008 and 2010, excluding live births from 2011 and 2012Birth weight was determined using NHSPIC data. Birth weight was categorized into six groups: < 1.0 kg, 1.0–1.4 kg, 1.5–1.9 kg, 2.0–2.4 kg, 2.5–4.0 kg (NBW), and > 4.0 kg.ADHD was diagnosed if the ICD-10 code F90 was reported twice in a child visiting the outpatient clinics or inpatient admission. We divided those with ADHD into two groups based on the presence or absence of prescription (including any history of being prescribed methylphenidate and/or atomoxetine). ASD cases were defined if the ICD-10 codes F84.0, F84.1, F84.5, F84.8, and F84.9 were reported at least twice. In addition, the age at diagnosis was identified using the date that the disease codes were first registered.Perinatal and socioeconomic factors associated with neurodevelopmental outcomes were identified using data from the NHIS database. Sex, history of congenital or perinatal diseases, and income level were used as adjustment variables. The type of insurance  and the NHIS premium based on income levels were used as proxy indicators of income level. Medical aid beneficiaries were defined as the lowest income group. Furthermore, the NHIS group was divided into four categories: Category 1, lower 25% premium; Category 2, 25–50% premium; Category 3, 50–75% premium; and Category 4, upper 25% premium. A child was defined as having a history of congenital or perinatal disease if they were diagnosed with at least one of the following ICD-10 codes during the first year of life: congenital malformations, deformations, and chromosomal abnormalities (Q codes); metabolic disorders (E70–E90); or neonatal conditions (P10–P96).Incidentally diagnosed and usually spontaneously regressing diseases, such as atrial septal defect (Q21.1) and patent ductus arteriosus (Q25.0), which are among the most prevalent 20 diseases in each category, were excluded to prevent over-adjustment  and R . Supplementary Information.


Previous research on sex ratio at birth (SRB) in India has largely relied on macro‐analysis of census data that do not contain the breadth of factors needed to explain patterns in SRB. Additionally, no previous research has examined the differentiation of factors associated with SRB across birth orders, a key determinant in societies affected by son preference. This study aims to fill these gaps using micro‐data related to 553,461 births occurring between 2005 and 2016 collected as part of the 2015–2016 National Family Health Survey. Analyses used multivariable logistic regressions stratified by birth order to examine associations with SRB at the national level. The SRB at birth order 1 was outside the biological normal limit, and generally increased with birth order. First births in households with wealth in the middle and richest quintiles, with mothers who desired a higher ideal number of sons than daughters, and in lower fertility communities had a higher probability of being male. Most SRB correlates were visible at birth orders 3 or higher. Programs and policies designed to address India's male‐skewed SRB must consider the diverse factors that influence SRB, particularly for higher order births. Concerns regarding sex ratio imbalance among children in India are decades old. This discussion acquired prominence during the early 1990s with the publication of the landmark article “More than 100 million women are missing” by Nobel Laureate Amartya Sen , and thaUnder normal circumstances, SRB varies between 103 and 106 male births per 100 female births  scheme. Households are selected in second stage using systematic sampling. In urban areas, census enumeration blocks are selected in first stage using PPS scheme and households are selected in second stage using systematic sampling. Studies have shown that data collected in NFHS are of reasonably good quality Bhat . MoreoveThe details of the variables included in the analysis are shown in Table The socioeconomic variables included in the statistical analysis are mother's schooling, wealth index, caste, religion, and landholding size of households. The wealth index, already included in the NFHS‐4 dataset, is a principal component analysis‐derived index of household assets and amenities  in the household—to account for the role of kinship structure in determining the SRB in India. Consanguineous marriage is defined as a marriage where the (current) husband was related to the wife in any way before she got married, coded as no/yes. Child marriage is defined as a marriage/cohabitation (whichever is earlier) initiated when the woman was younger than age 18. Household structure is coded as nuclear versus non‐nuclear. To account for the influence of mothers‐in‐law or mothers, we constructed a proxy variable assessing the presence of an elderly woman (60+) in the household.We fit multivariable logistic regression models to examine the association between the variables listed in Table The SRB generally increased with an increase in birth order, ranging from 107.5 for birth order 1 to 112.3 for birth orders 3 or higher (Table Table We found higher SRB in urban areas (111.4) than in rural (108.8) areas. In terms of geographic regions, the SRB was highest in the north (116.0) and lowest in the northeast (105.8). The SRB was also elevated in the west (111.4) and the central regions (109.2). Interestingly, the south, which is not known for sex selection, has a SRB that is outside of the normal range (107.5).Of the four kinship structure‐related variables, only household structure and presence of an elderly woman in the household were associated with the SRB in the bivariate analysis. The SRB was lower in nuclear households (107.9) compared with non‐nuclear households (111.0). Likewise, the SRB was lower in households without an elderly woman (108.8) compared with households with an elderly woman (112.3).Multivariable regression results at the national level are presented in Table As with birth order 1, a limited number of variables were associated with the probability of a male birth at birth order 2. The absence of a living male sibling was associated with a higher probability of male birth. The odds of a male birth were higher among mothers who had no living son  than among mothers who already had a son. Mothers who desired higher ideal number of sons than daughters had higher odds of a male birth  than did their counterparts who did not report a preference for more sons. The effect of average fertility at the community level became stronger at birth order 2. The odds of a male birth were 10 percent higher  among mothers from the richest household wealth quintile than among mothers from poorest quintile. Mothers from ST and SC were significantly less likely to have a male birth compared with mothers who were not from a ST, SC, or OBC. Likewise, Muslim mothers were less likely to have a male birth compared with Hindu mothers. Interestingly, mothers from households having 10 acres or more land had higher odds of a male birth  than did mothers from households that do not own land. We also found that mothers from the north and central regions were more likely to have a male birth than mothers from the south.Most SRB correlates are visible at birth orders 3 or higher. The absence of a living male sibling  and the difference in the desired ideal number of sons and daughters  were positively associated with the probability of a male birth. Average fertility at the community level was also associated with the probability of a male birth. Mothers in communities where the average number of children per woman was between 2.2 and 2.8 were 1.06  times as likely as having a male birth compared with mothers in communities where the average number of children per woman is greater than 2.8. Likewise, mothers in communities where the average number of children per woman was between 1.6 and 2.1 were 1.06  times as likely as having a male birth compared with mothers in communities where the average number of children per woman is greater than 2.8. Similarly, mothers in communities where the average number of children per woman was less than 1.6 were 1.13  times as likely as having a male birth compared with mothers in communities where the average number of children per woman is greater than 2.8.The probability of a male child was also associated with mother's schooling. The odds of a male birth were 25 percent higher  among mothers having schooling higher than secondary, and 7 percent higher among mothers with secondary schooling  than among mothers with no schooling. Mothers from the middle , richer , and richest  quintiles were more likely to have a male birth than mothers from the poorest quintile. Mothers from ST and SC were less likely to have a male birth compared with mothers who are not from a ST, SC, or OBC. Muslim mothers were less likely than Hindu mothers to have a male birth . Mothers from the north, central, east, northeast, and west regions were more likely to have a male birth than mothers from the south. The landholding size of the household was also associated with SRB at birth orders 3 or higher .Our study provides robust estimates of the SRB in India by various socioeconomic, demographic, residence‐related, and the kinship‐related variables. Importantly, we also provide 95 percent CIs for the estimated SRBs in India, facilitating comparison across groups. We estimate a national SRB of 109.2 for births occurring between 2005 and 2016. This is comparable to SRBs reported in other studies, including the Indian SRS (SRB of 110.7 for 2005–2015) and the District Level Household Survey 2007–2008 (SRB of 109.6 for 2004–2008) IIPS . While tSuch high levels of the SRB have also been observed in other south Asian countries marked by considerable son preference. For example, the SRB for China from the 2005 Intercensal Survey was 120.5, and the Official Estimate for 2009 was 119.5. The first 2010 census estimate is 118.1 Li, . In SoutThere is generally an absence of SRB data stratified across birth orders in India. The importance of filling this gap is demonstrated in our study, in which SRB varied considerably by birth order. Although the SRB was highest for third or higher order births (112.3), even the SRB at birth order 1 (107.5) exceeded the normal range. The only study from India that provides a comparable estimate of the SRB at birth order 1 uses data from 1998‐1999 to show a SRB of 106.9 at birth order 1, suggesting almost no change in the SRB at birth order 1 in India in almost 20 years  in the south is outside the biological normal limit. This evidence indicates that, despite the popular assumption that son preference is not a concern in the south; couples in this region are also adopting sex selection to have sons, although to a much smaller extent than seen in other regions of India.A comparison of our results with Bhat and Zavier  suggestsA key strength of our study is the use of over 553,000 births occurring between 2005 and 2016 in representative households to study the factors associated with SRB in India. Due to the micro nature of data, we were able to include a number of important variables including kinship‐structure related variables, landholding size of households, and the average fertility at the community level into the regression models. This study also has some important limitations. First, we could not account for genetic factors and under‐reporting of female children (if any) due to unavailability of data. There is a possibility in societies highly affected by son preference that the mother reports her son(s) first and then the daughter(s), affecting our estimates. However, this risk is lessened with the NFHS‐4 questionnaire, in which mothers were asked to list all births in the order in which they occurred starting with her first birth. Second, we could not include certain variables like women's work and father's characteristics, as in NFHS‐4, this information was only collected in 15 percent of the randomly selected households. Third, although we controlled for state‐regions in regressions, we could not fully capture the cultural practices and norms regarding son preference or daughter aversion, level of patriarchy in different geographical regions of India due to nonavailability of data in NFHS‐4. Finally, since the SRB is highly affected by sample size, any analysis of SRBs estimated from survey data should be interpreted with caution. For example, for an observed sex ratio of 107, the 95 percent CI is 94.5, 121.2 if the estimation is based on a sample of 1,000 births, 101.2, 113.1 if based on a sample of 5,000 births, 102.9, 111.3 if based on a sample of 10,000 births, and 105.7, 108.3 if based on a sample of 100,000 births, even for samples derived without considering clustering. The confidence intervals are likely to be even wider for large‐scale sample surveys, which are largely multistage cluster samples. Fortunately, our analysis is based on very large samples, thus providing robust estimates of the SRB at the national level.Our in‐depth analysis of diverse factors associated with the SRB across birth orders in India offers several key insights. The SRB at birth order 1 is above the normal upper limit for the country as a whole and across national regions, which is a matter of great concern and requires further explanatory research. Lower levels of community fertility were associated with higher SRB for all birth orders, underlining the role of fertility decline in distorting SRB in favor of males. Our findings also call for more debate around the landholding‐patriarchy hypothesis to formulate policies and programs that directly address son preference and gender‐based discrimination. Implementing equal land rights law and restricting the male dominance in ownership and inheritance of land may be inadequate in the absence of policies and programs to change cultural norms regarding patriarchy and patrilocality. In absence of such policies, implementation of equal land rights law may actually exacerbate son preference in India (Bhalotra et al. Our analysis is based on 553,461 births occurring between 2005 and 2016 in households interviewed in NFHS‐4. The NFHS‐4 is a publically available dataset with no individual identifiers in place. Hence, our study is exempt from ethical approval.Supporting InformationClick here for additional data file.


No significant intergroup differences were observed at the other weeks. Haemoglobin monitoring during the first week of postnatal life may be useful to guide ROP screening in premature infants.Retinopathy of prematurity (ROP) is a proliferative retinal vascular disorder attributed to an ischaemic stimulus in preterm infants. Haemoglobin, the main component for oxygen transportation, may be implicated in ROP development. This retrospective study compared the mean weekly haemoglobin levels between infants with and without ROP over the first six weeks of life. Premature infants of less than 32 weeks gestational age and less than 1.5 kg birth weight were grouped into age and birth weight-matched ROP cases and controls. Weekly mean haemoglobin levels were documented. An independent t-test was used to analyze the difference in mean haemoglobin levels between infants with ROP and infants without ROP. Adjustment for confounders was performed using one-way analysis of covariance. There was a statistically significant difference in adjusted mean haemoglobin levels between the ROP and non-ROP group during the first week of life ( Retinopathy of prematurity (ROP) is a major cause of preventable childhood blindness ,2,3, chaROP screening is performed in infants with a birth weight of less than 1500 g and gestational age of less than 32 weeks ,11. ScreStudies regarding the role of haemoglobin in ROP have yielded varying conclusions ,18,19,20A retrospective study was performed among premature infants admitted to Hospital Universiti Sains Malaysia from September 2016 to December 2019. Approval was obtained from the Human Research Ethics Committee of Universiti Sains Malaysia (USM/JEPeM/18090441). The tenets of the declaration of Helsinki were adhered to throughout. Premature infants of less than 32 weeks gestational age and less than 1.5 kg birth weight were included. Those with congenital deformities, ocular diseases, or individual/parental history of haemoglobin-related disease  were excluded. The ROP cases were equally matched with non-ROP controls (1:1) of equal gestational age and birth weight. Extremely small gestational age or low birth weight infants who could not be matched with the control group were excluded.2EDTA tube. Culture-proven sepsis was defined as one episode of positive blood culture during the first six weeks of life. ROP was staged based on the revised ‘International Classification of Retinopathy of Prematurity’ [Birth weight, gestational age, volume of blood transfusion, duration of oxygen supplementation, culture-proven sepsis, intraventricular haemorrhage, enterocolitis, congenital heart disease, pneumonia, gender, ROP stage, requirement for ROP treatment, and weekly mean haemoglobin levels were collected from birth until week six of life. Haemoglobin levels were measured using the Automated Blood Cell Analyzer , with 500 microLiters of blood per phlebotomy collected in a Katurity’ ,22. Thisaturity’ .Statistical analyses were performed using IBM SPSS Statistics for Windows, Version 26.0 . An independent t-test was used to determine the mean differences in numerical variables between ROP and non-ROP infants. A chi-square test was performed to determine the differences in categorical risk factors between the two groups. An independent t-test was also performed to determine the mean differences in weekly mean haemoglobin levels from birth to week six of life between ROP and non-ROP infants. The mean haemoglobin level was then adjusted for confounding factors using one-way analysis of covariance (ANCOVA). Comparison of mean haemoglobin level between ROP cases requiring treatment and controls was similarly performed.p = 0.968), nor in birth weight (p = 0.443). Infants with ROP had a significantly higher volume of total blood transfusion, longer days of oxygen supplementation, and a higher proportion of culture-proven sepsis than infants without ROP (p < 0.001). The clinical characteristics of all the infants are summarized in A total of 62 premature infants were included (31 in the ROP group and 31 in the control group). The ROP and non-ROP groups did not differ significantly in gestational age (p = 0.002). This difference persisted even after adjustment for confounders (p = 0.038). There were no significant differences in mean haemoglobin level between the two groups at birth, nor from week two until week six of life , week 1 (p = 0.02), week 3 (p = 0.012) and week 4 (p = 0.013). These differences were not observed after adjustment for confounders  experienced decreases in mean haemoglobin level from birth till the sixth week of life . This isBlood transfusion and low haemoglobin are inextricably intertwined in the pathogenesis of ROP ,42. Low Haemoglobin in neonates at birth predominantly consists of foetal haemoglobin, which has a higher affinity for oxygen than adult haemoglobin . Blood tSepsis has been associated with ROP by various mechanisms . Low birInfants with untreated ROP have a wide range of vision outcomes, with no light perception as the worst-case scenario . Even inTo the best of our knowledge, this is the only study focusing on haemoglobin levels in infants with and without ROP that controls for gestational age and birth weight. As haemoglobin levels are lower in more premature infants as well as those with lower birth weight , failureInfants with ROP have significantly lower mean haemoglobin levels than infants without ROP during the first week of life. These findings may guide future ROP screening in high-risk infants.


Measles is endemic in Africa; measles mortality is highest among infants. Infant measles antibody titer at birth is related to maternal immune status. Older mothers are likelier to have had measles infection, which provides higher antibody titers than vaccine-induced immunity. We investigated the relationship between maternal age and measles susceptibility in mother-infant pairs in Mali through six months of infancy.We measured serum measles antibodies in 340 mother-infant pairs by plaque reduction neutralization test (PRNT) and calculated the proportion of mothers with protective titers (>120 mIU/mL) at delivery and the proportion of infants with protective titers at birth, and at three and six months of age. We explored associations between maternal age and measles antibodies in mothers and infants at the timepoints noted.Ten percent of Malian newborns were susceptible to measles; by six months nearly all were. Maternal and infant antibody titers were highly correlated. At delivery, 11% of mothers and 10% of newborns were susceptible to measles. By three and six months, infant susceptibility increased to 72% and 98%, respectively. Infants born to younger mothers were most susceptible at birth and three months. Time to susceptibility was 6.6 weeks in infants born to mothers with measles titer >120–<430 mIU/mL versus 15.4 weeks when mothers had titers ≥430 mIU/mL.Maternal and newborn seroprotective status were positively correlated. Improved strategies are needed to protect susceptible infants from measles infection and death. Increasing measles immunization coverage in vaccine eligible populations, including nonimmune reproductive-aged women and older children should be considered. The study involved active monitoring for influenza-like illness through the first six months of life. Serum samples were obtained longitudinally from mothers and infants at birth, and at three and six months that were consented for future use 22.1For the original influenza vaccination trial, 4,425 mothers were recruited in the third trimester of pregnancy from referral and community health centers in urban Bamako, Mali, between September 2011 and April 2013; 4,193 of them were randomly assigned (1:1) to study intervention . Exclusion criteria, enrollment, and additional study methods have been described in detail elsewhere 2.2A subsample of eligible mother-infant pairs (n = 340) was randomly selected from the maternal influenza study to investigate seroprotection status (circulating measles antibody levels) as a risk factor for infant susceptibility to measles. Mother-infant pairs were eligible for measles antibody analysis if the mother was 15–39 years old at the time of (singleton) birth and had completed all three scheduled visits at birth, three months, and six months.2.3Mothers in the original study were stratified into five age groups: 15–19, 20–24, 25–29, 30–34, and 35–39 years. An equal number of mother-infant pairs (n = 68) in each stratum achieved 90% power to detect a linear trend in the proportion of infants with protective maternal measles titer across the five age groups using a Cochran-Armitage test and a significance level of 0.05. The sample size was estimated using PASS v 14.09  assuming equally spaced proportions from 0.70 to 0.90.2.42. The serum-virus mix was transferred onto ∼90% confluent Vero cell monolayers (ATCC) seeded in 24-well plates (in duplicate) and incubated for 1 h. After incubation the liquid was removed; cells were overlaid with 1% carboxymethylcellulose  and incubated for 5 days at 37 °C, 5% CO2. On day 5, 0.5 mL of neutral red stain  diluted in Temin’s Modified Eagles Medium supplemented with 4% fetal bovine serum  was added and incubated overnight at 37 °C, 5% CO2. The stained overlay was aspirated, fixed with 0.5 mL of 10% formalin solution  and allowed to dry overnight (covered). Each well was scanned using the Immunospot S6 Macro Analyzer. Cytopathic plaques were counted with Biospot Pro version 7.0 software . PRN titers were calculated using the Reed-Muench method as the inverse of the dilution that inhibited 50% plaques compared with no serum control and reported in mIU/mL based on the 3rd International WHO (97/648) reference standard .Measles plaque reduction neutralization tests (PRNT) were performed, as previously described, with modifications 2.5Date of birth or enrollment age was used to calculate maternal year of birth. Measles cases and MCV delivered via RI and SIA in Mali by year were plotted against maternal year of birth as a proxy for measles exposures 3Maternal year of birth ranged from 1972 to 1997 . MothersOf mothers, an average of 11% lacked protective measles titers at delivery; percentages ranged from 6% in mothers in the 30–34 year age group up to 19% in mothers in the 25–29 year age group. The proportion of mothers susceptible at delivery was not associated with maternal age group , although the 30–34 and 35–39 year age groups had higher measles antibody levels than mothers in younger age groups  .Table 1SAmong infants, 10% were susceptible to measles at birth; the proportion of newborns susceptible to measles (<120 mIU/mL) was highest in those born to mothers aged 15–19 years (21%) and lower in those born to older maternal age groups (3–11%)  . InfantsIn infants, maternally derived measles antibodies decayed rapidly over time. By three months of age, most (72%) infants were susceptible to measles , Fig. 2;Estimates of average population and individual infant measles antibody decline in relation to maternal immune status are shown in 4In this cohort of pregnant women recruited from health centers in Bamako, Mali, an area with endemic measles transmission and a measles vaccination program since 1985, we observed statistically significant positive associations between maternal age and infant measles antibody at delivery. Additionally, maternal age was associated with higher infant titers and protection against measles at three months. Measles titers in the infants at birth were highly correlated with maternal antibody titers, regardless of maternal age. Ten percent of infants were susceptible to measles at birth. By three months, most infants were susceptible to measles. At birth and three months, the proportion of susceptible infants was lower among those born to older mothers compared with infants born to younger ones, which could be explained by the higher measles titers among older mothers at the time of the study. By six months, virtually all infants were susceptible to measles, regardless of maternal age. Among the infants who were seroprotected the longest, most started with higher measles titers. Maternal measles antibody level at delivery was observed to have the strongest correlation with infant seroprotective status: infants born to mothers with a strongly positive immune status (>430 mIU/mL) had the highest average titers at birth and those antibodies lasted longer.Higher measles titers in older mothers could be explained by increased likelihood that those born before 1985 had been infected by wild-type measles virus, while younger mothers may have received measles vaccine after its introduction into the RI program in 1985 and/or through measles SIAs. Also, as measles transmission decreased, reflected in fewer reported measles cases, opportunities for immunological boosting from exposure to circulating measles virus may have been reduced.Some mothers lacked protective levels of measles antibodies and were susceptible to measles, which suggests that they were neither infected with wild-type measles virus nor effectively vaccinated. Less commonly, adult susceptibility may result from waning immunity. The infants born to susceptible mothers were susceptible to measles from birth. This is a serious risk in a region of high measles transmission because infants experience the most severe disease. Likewise, the observation that most three-month-old and virtually all six-month-old infants were susceptible to measles in this sample cohort is concerning. In this study population, measles susceptibility starts much earlier than anticipated, with susceptibility spanning >6 months before MCV1 eligibility for most infants.In a previous study by Tapia, with a different sample of Malian infants, measles antibody levels were examined in infants with neither history of infection nor vaccination To reduce infant vulnerability to measles, some authors have proposed decreasing the age of MCV1 administration An important strength of our study is its prospective, longitudinal design. A second strength is the quantification of measles neutralizing antibodies. There is an accepted immune correlate against measles based on PRNT, considered the gold standard to predict protection from measles infection and disease A second dose of measles-containing vaccine (MCV2), scheduled at age 12 months, was introduced in the RI program in December 2019. Our study population exhibits a wide seroprevalence and includes individuals who may have been previously infected with wild-type measles, vaccinated, both, or neither. As this region remains heavily affected by measles One study limitation is the lack of information on individual maternal and infant measles infection and vaccination, each of which may have influenced measles antibody titers. While we attempted to use maternal year of birth alongside population-level vaccination  and case data as a proxy for measles exposures, these sources are not representative of individuals, and incidence of measles may be underreported due to weak surveillance 5In Bamako, Mali, infant measles titer at birth was highly correlated with maternal measles titer at delivery, regardless of maternal age. For both Malian mothers and infants, 10% or more were susceptible to measles at delivery and at birth, respectively. Infant susceptibility was higher among infants born to younger mothers. By three months, most infants were susceptible to measles and by six months virtually all infants were susceptible, leaving many infants susceptible for months before the recommended age of MCV1 administration. These results emphasize the urgent need to achieve high routine coverage at nine months of age in Mali and to increase measles immunization coverage among nonimmune reproductive-aged women and older children, including via catch-up vaccination throughout the life course. These steps would shield infants <9 months of age from measles infection, complications, and death. Lastly, more research is needed to understand measles susceptibility among reproductive-aged women and infants, particularly in the AFR region.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.


Accurate prediction of drug–target interactions (DTI) is crucial for drug discovery. Recently, deep learning (DL) models for show promising performance for DTI prediction. However, these models can be difficult to use for both computer scientists entering the biomedical field and bioinformaticians with limited DL experience. We present DeepPurpose, a comprehensive and easy-to-use DL library for DTI prediction. DeepPurpose supports training of customized DTI prediction models by implementing 15 compound and protein encoders and over 50 neural architectures, along with providing many other useful features. We demonstrate state-of-the-art performance of DeepPurpose on several benchmark datasets.https://github.com/kexinhuang12345/DeepPurpose.Bioinformatics online. Drug–target interactions (DTI) characterize the binding of compounds to protein targets .et al., 2019; Deep learning (DL) has advanced traditional computational modeling of compounds by offering an increased expressive power in identifying, processing and extrapolating complex patterns in molecular data  string and protein amino acid sequence pair as input. Then, they are fed into molecular encoders which specifies a deep transformation function that maps compounds and proteins to a vector representation. In particular, for compounds, DeepPurpose provides eight encoders using different modalities of compounds: Multi-Layer Perceptrons (MLP) on Morgan, PubChem, Daylight and RDKit 2D Fingerprint; Convolutional Neural Network (CNN) on SMILES strings; Recurrent Neural Network (RNN) on top of CNN; transformer encoders on substructure fingerprints; message passing graph neural network on molecular graph. For proteins, DeepPurpose provides seven encoders for the input amino acid sequence: MLP on Amino Acid Composition (AAC), Pseudo AAC, Conjoint Triad, Quasi-Sequence descriptors; CNN on amino acid sequences; RNN on top of CNN; transformer encoder on substructure fingerprints. Note that alternative input features may not work for a specific encoder architecture. The detailed encoder specifications and references are described in DeepPurpose feeds the learned protein and compound embeddings into an MLP decoder to generate predictions. Output scores include both continuous binding scores, such as the median inhibitory concentration  Load the dataset from a local file or load a DeepPurpose benchmark dataset. (ii) Specify the names of compound and protein encoders. (iii) Split the dataset into training, validation and testing sets using data_process function, which implements a variety of data-split strategies. (iv) Create a configuration file and specify model parameters. If needed, DeepPurpose can automatically search for optimal values of hyper-parameters. (v) Initialize a model using the configuration file. Alternatively, the user can load a pre-trained model or a previously saved model. (vi) Finally, train the model using train function and monitor the progress of training and performance metrics. DeepPurpose is OS-agnostic and uses the Jupyter Notebook interface. It can be run in the cloud or locally. All datasets, models, documentation, installation instructions and tutorials are provided at To demonstrate the use of DeepPurpose, we compare DeepPurpose with KronRLS . A complIn addition to rapid model prototyping, DeepPurpose also provides utility functions to load a pre-trained model and make predictions for a new drug and target inputs. This functionality allows domain scientists to examine predictions quickly, modify the inputs based on predictions, and iterate on the process until finding a drug or target with desired properties. We leverage Gradio (Financial Support: none declared.M.Z. and K.H. are supported, in part, by NSF grant nos. IIS-2030459 and IIS-2033384, and by the Harvard Data Science Initiative. T.F. and J.S. was in part supported by the NSF SCH-2014438, IIS-1418511, CCF-1533768, IIS-1838042, the NIH award NIH R01 1R01NS107291-01 and R56HL138415.Conflict of Interest: none declared.btaa1005_Supplementary_DataClick here for additional data file.


Arterial pseudoaneurysm can manifest in almost all arteries, but peripheral ones such as brachial artery pseudoaneurysm are rare and typically happen after trauma or infections. We describe an 8-year-old boy who presented with a large nonpulsatile soft tissue mass-like lesion 20 days after supracondylar fracture of the humerus which was fixed using Kirschner wire. The neurovascular examination was normal; CT angiography revealed a large pseudoaneurysm arising from the left profunda brachii artery. The patient went under surgical repair and was discharged from the hospital with an uneventful postop course. A high index of suspicion is necessary in cases with humeral fractures for the early diagnosis of pseudoaneurysm where the delayed diagnosis may cause fatal outcomes. Arterial pseudoaneurysm can manifest in almost all arteries, but peripheral ones such as brachial artery aneurysms are rare and typically happen after trauma or infections , 2. SuprAn 8-year-old boy with no significant past medical history sustained a closed supracondylar fracture of the left humerus due to falling down. The initial X-ray demonstrated a type III fracture based on Gartland classification . He was Based on the necrotic overlying skin, the patient was emergently transferred to the operation room in which after heparinization and proximal control by a tourniquet, and the sac of pseudoaneurysm was opened and approached through a left lateral arm incision . The necAlthough upper extremity peripheral pseudoaneurysm of the arteries is rare, they can happen iatrogenically and after trauma, especially in upper extremity fractures. Nowadays, the total rate of pseudoaneurysms has increased due to the widespread use of peripheral endovascular procedures from 0.04% before 2000 to 0.7% in 2019 , 6. ArteAsavamongkolkul and Ruangsetakit reported pseudoaneurysm of the brachial artery after supracondylar fracture in a 3-year-old boy. Similar to our case, the patient was treated using Kirschner wire fixation after an open reduction in the operating room. In this case, the patient presented with a slowly growing nonpulsatile soft tissue mass on the medial aspect of the left elbow with audible bruit. However, in contrast to our case, the interval of the initiation of symptoms was much longer, and it was found that the tip of the Kirschner wire was stuck in the pseudoaneurysm that could penetrate the brachial artery in some positions, which was not the case in our study. Also, the patient in their study developed malunion, while ours recovered after surgery without any complications in the follow-up visits .Kemp et al. described an 82-year-old man who was referred to their clinic due to a painless pulsatile soft tissue mass with bruit following a comminuted fracture of the right humerus. He was treated with a hanging cast; however, since the incident, he developed loss of dexterity in his right hand and paresthesia. CT angiography confirmed the presence of a large brachial pseudoaneurysm. Therefore, he was transferred to the operating room for the surgical repair of the pseudoaneurysm. On close inspection during surgery, it was found that the sac contained a sharp fragment of the humerus with a single puncture wound in the brachial artery which was the reason for pseudoaneurysm formation [Moran et al. reported a 65-year-old female who presented with a large pulsatile soft tissue mass in the middle third of the left humerus 6 months after the humeral fracture which was fixed with an intramedullary nail. The patient presented with reduced sensation in the median nerve territory along with mild thenar muscle wasting. A pseudoaneurysm with the largest diameter of 5.8 cm was diagnosed with duplex sonography which was due to a break of proximal locking screw of the intramedullary nail. Although humeral fracture was fixed with an intramedullary nail, the patient developed brachial pseudoaneurysm .It is worth mentioning that although orthopedic references put an emphasis on considering anterior approach for exploration and reconstruction. However, our patient developed iatrogenic pseudoaneurysm of the profunda brachii due to penetration of Kirschner wires used in open reduction and internal fixation through posterior approach. When utilizing posterior approach, persuasion should be taken to avoid neurovascular damage too while using Kirschner wires. Moreover, it should be mentioned that orthopedic surgeons must take the vascular complications in patients' follow-ups as well as other complications such as nerve damage, stiffness, and infection into consideration. This case emphasizes the importance of clinical suspicion to pseudoaneurysm even if the distal pulses were palpated and duplex sonography reveals normal arterial flow. Furthermore, close vascular observation must be done in the setting of well-perfused hand in cases of displaced supracondylar fractures before and after surgery.Pseudoaneurysm is a complication that presents itself gradually and can be either asymptomatic or symptomatic, in which any external instrument or fragments of fracture with a sharp end can cause its formation. A high index of suspicion is necessary in cases with humeral fractures for the early diagnosis of pseudoaneurysm where the delayed diagnosis may cause further complications.