Improved iodine status is associated with improved mental performance of schoolchildren in Benin. Persistence of goiter despite oral iodine supplementation in goitrous children with iron deficiency anemia in Côte d'Ivoire. Iodine supplementation improves cognition in iodine-deficient schoolchildren in Albania: a randomized, controlled, double-blind study. Iodine supplementation improves cognition in mildly iodine-deficient children. Attention deficit and hyperactivity disorders in the offspring of mothers exposed to mild-moderate iodine deficiency: a possible novel iodine deficiency disorder in developed countries. The effects of oral iodized oil on intelligence, thyroid status, and somatic growth in school-age children from an area of endemic goiter. Iodine supplementation in pregnancy and its effect on child cognition. The Danish investigation on iodine intake and thyroid disease, DanThyr: status and perspectives. Treatment of iodine deficiency in school-age children increases insulin-like growth factor (IGF)-I and IGF binding protein-3 concentrations and improves somatic growth. Reappraisal of the risk of iodine-induced hyperthyroidism: An epidemiological population survey Treatment of iron deficiency in goitrous children improves the efficacy of iodized salt in Côte d'Ivoire. Infant neurocognitive development is independent of the use of iodised salt or iodine supplements given during pregnancy. Addition of microencapsulated iron to iodized salt improves the efficacy of iodine in goitrous, iron-deficient children: a randomized, double-blind, controlled trial. Thyroid size and goiter prevalence after introduction of iodized salt: a 5-y prospective study in schoolchildren in Côte d'Ivoire. Comparison of two different doses of iodide in the prevention of gestational goiter in marginal iodine deficiency: a longitudinal study. Prevention of iodine deficiency disorders by oral administration of lipiodol during pregnancy. Earliest prevention of endemic goiter by iodine supplementation during pregnancy.
BACKGROUND An adequate iodine supply in utero and shortly after birth is known to be crucial to an individual 's physical and mental development . The question of whether iodine supplementation later in life can exert a favorable influence on the mental performance of iodine-deficient population s was addressed in various studies , but with contradictory results . OBJECTIVE The aim of this study was to examine the effect of an improvement in iodine status on mental and psychomotor performance of schoolchildren ( 7 - 11 y ) who were moderately to severely iodine deficient . DESIGN The study , which was originally planned as a double-blind , r and omized , placebo-controlled intervention , was carried out in an iodine-deficient population of schoolchildren ( n = 196 ) in northern Benin . As the population began to have access to iodized salt during the 1-y intervention period , the study population was split post hoc-on the basis of urinary iodine concentrations-into a group with improved iodine status and a group with unchanged iodine status . Changes in mental and psychomotor performance over the intervention period were compared . RESULTS Children with increased urinary iodine concentrations had a significantly greater increase in performance on the combination of mental tests than did the group with no change in urinary iodine concentrations . CONCLUSIONS An improvement in iodine status , rather than iodine status itself , determined mental performance in this population , which was initially iodine deficient . These findings suggest a " catch-up " effect in terms of mental performance BACKGROUND In developing countries , many children are at high risk of goiter and iron deficiency anemia . Because iron deficiency can have adverse effects on thyroid metabolism , iron deficiency may influence the response to supplemental iodine in areas of endemic goiter . OBJECTIVE The aim of this study was to determine whether goitrous children with iron deficiency anemia would respond to oral iodine supplementation . DESIGN A trial of oral iodine supplementation was carried out in an area of endemic goiter in western Côte d'Ivoire in goitrous children ( n = 109 ) aged 6 - 12 y. Group 1 ( n = 53 ) consisted of goitrous children who were not anemic . Group 2 ( n = 56 ) consisted of goitrous children who had iron deficiency anemia . At baseline , thyroid gl and volume and urinary iodine , thyrotropin , and thyroxine were measured by using ultrasound . Each child received 200 mg I orally and was observed for 30 wk , during which urinary iodine , thyrotropin , thyroxine , hemoglobin , and thyroid gl and volume were measured . RESULTS The prevalence of goiter at 30 wk was 12 % in group 1 and 64 % in group 2 . The mean percentage change from baseline in thyroid volume 30 wk after administration of oral iodine was -45.1 % in group 1 and -21.8 % in group 2 ( P < 0.001 ) . Among the anemic children , there was a strong correlation between the percentage decrease in thyroid volume and hemoglobin concentration ( r(2 ) = 0.65 ) . CONCLUSION The therapeutic response to oral iodine was impaired in goitrous children with iron deficiency anemia , suggesting that the presence of iron deficiency anemia in children limits the effectiveness of iodine intervention programs BACKGROUND Iodine is required for the production of thyroid hormones , which are necessary for normal brain development and cognition . Although several r and omized trials examined the effect of iodine supplementation on cognitive performance in schoolchildren , the results were equivocal . OBJECTIVE We aim ed to ascertain whether providing iodized oil to iodine-deficient children would affect their cognitive and motor performance . DESIGN In a double-blind intervention trial , 10 - 12-y-old children ( n = 310 ) in primary schools in rural southeastern Albania were r and omly assigned to receive 400 mg I ( as oral iodized oil ) or placebo . We measured urinary iodine ( UI ) , thyroid-stimulating hormone ( TSH ) , and total thyroxine ( TT4 ) concentrations and thyroid gl and volume ( by ultrasound ) . The children were given a battery of 7 cognitive and motor tests , which included measures of information processing , working memory , visual problem solving , visual search , and fine motor skills .  Thyroid ultrasound and the biochemical and psychological tests were repeated after 24 wk . RESULTS At baseline , the children 's median UI concentration was 43 microg/L ; 87 % were goitrous , and nearly one-third had low concentrations of circulating TT4 . Treatment with iodine markedly improved iodine and thyroid status : at 24 wk , median UI in the treated group was 172 microg/L , mean TT4 was approximately 40 % higher , and the prevalence of hypothyroxinemia was < 1 % . In the placebo group after the intervention , these variables did not differ significantly from baseline . Compared with placebo , iodine treatment significantly improved performance on 4 of 7 tests : rapid target marking , symbol search , rapid object naming , and Raven 's Coloured Progressive Matrices ( P < 0.0001 ) . CONCLUSION Information processing , fine motor skills , and visual problem solving are improved by iodine repletion in moderately iodine-deficient schoolchildren BACKGROUND The effects of severe iodine deficiency during critical periods of brain development are well documented . There is little known about the consequences of milder forms of iodine deficiency on neurodevelopment . OBJECTIVE The objective was to determine whether supplementing mildly iodine-deficient children with iodine improves cognition . DESIGN A r and omized , placebo-controlled , double-blind trial was conducted in 184 children aged 10 - 13 y in Dunedin , New Zeal and . Children were r and omly assigned to receive a daily tablet containing either 150 microg I or placebo for 28 wk .  Biochemical , anthropometric , and dietary data were collected from each child at baseline and after 28 wk . Cognitive performance was assessed through 4 subtests from the Wechsler Intelligence Scale for Children . RESULTS At baseline , children were mildly iodine deficient [ median urinary iodine concentration ( UIC ) : 63 microg/L ; thyroglobulin concentration : 16.4 microg/L ] . After 28 wk , iodine status improved in the supplemented group ( UIC : 145 microg/L ; thyroglobulin : 8.5 microg/L ) , whereas the placebo group remained iodine deficient ( UIC : 81 microg/L ; thyroglobulin : 11.6 microg/L ) . Iodine supplementation significantly improved scores for 2 of the 4 cognitive subtests [ picture concepts ( P = 0.023 ) and matrix reasoning ( P = 0.040 ) ] but not for letter-number sequencing ( P = 0.480 ) or symbol search ( P = 0.608 ) . The overall cognitive score of the iodine-supplemented group was 0.19 SDs higher than that of the placebo group ( P = 0.011 ) . CONCLUSIONS Iodine supplementation improved perceptual reasoning in mildly iodine-deficient children and suggests that mild iodine deficiency could prevent children from attaining their full intellectual potential . The trial was registered with the Australia New Zeal and Clinical Trials Register as ACTRN12608000222347 Over a period of almost 10 yr , we carried out a prospect i ve study of the neuropsychological development of the offspring of 16 women from a moderately iodine-deficient area ( area A ) and of 11 control women from a marginally iodine-sufficient area ( area B ) whose thyroid function had been monitored during early gestation .  Attention deficit and hyperactivity disorder ( ADHD ) was diagnosed in 11 of 16 area A children ( 68.7 % ) but in none from area B. Total intelligence quotient score was lower in area A than in area B children ( 92.1 + /- 7.8 vs. 110 + /- 10 ) and in ADHD children when compared with both non-ADHD children from the same area and control children ( 88.0 + /- 6.9 vs. 99.0 + /- 2.0 and 110 + /- 10 , respectively ) . Seven of 11 ADHD children ( 63.6 % ) were born to the seven of eight area A mothers who became hypothyroxinemic at early gestation , whereas only one of five non-ADHD children was born to a woman who was hypothyroxinemic at 20 wk of gestation . So far , a similar prevalence of ADHD has been reported only in children with generalized resistance to thyroid hormones . This might suggest a common ADHD pathogenetic mechanism consisting either of reduced sensitivity of the nuclear receptors to thyroid hormone ( generalized resistance to thyroid hormones ) or reduced availability of intracellular T3 for nuclear receptor binding . The latter would be the ultimate consequence of maternal hypothyroxinemia ( due to iodine deficiency ) , result ing in a critical reduction of the source of the intracellular T3 available to the developing fetal brain One hundred goitrous school children received 475 mg iodized oil by mouth , while 100 controls received mineral oil , on a double-blind basis . On follow-up 22 months later the urinary iodine had increased and goiter size had decreased in both groups , more strikingly in the iodine-treated children . There were no consistent differences between the two treatment groups in rate of somatic growth or performance on the Stanford-Binet and Bender tests . Because of the complexities introduced by increases in urinary iodine in the controls , we compared goiter reduction with improvement in IQ score in all children , regardless of group , and found a significant relationship ( p = 0.014 ) , particularly in girls ( p = 0.029 ) . We conclude that oral iodized oil is an attractive alternative to its injection but we recommend an approximate doubling of the dose used here for more effective control . Also , while our data are not conclusive , they support the possibility that correction of iodine deficiency may improve mental performance in school age children , particularly girls Maternal hypothyroidism and hypothyroxenemia due to iodine deficiency have been shown to affect development of the newborn negatively . Maternal iodine supplementation may therefore improve cognitive performance of the offspring , even in areas of mild-to-moderate iodine deficiency ( ID ) . Several iodine supplementation studies have been performed in mildly ID pregnant women in Europe . These studies have shown that iodine supplementation increases maternal urinary iodine ( UI ) excretion and reduces thyroid volume , as well as prevents increases in infant thyroid volume and thyroglobuline . However , r and omized controlled studies with long-term outcomes are lacking . Therefore , two trials were started in 2008 in areas of low iodine status ; one in Bangalore , India ( n=325 ) , and another in Bangkok , Thail and ( n=514 ) . Pregnant women were recruited < 14 weeks gestational age and r and omized to either receive a daily dose of 200 μg I ( as KI ) or an identical placebo throughout pregnancy . Both trials are ongoing , and women are followed up during pregnancy and at delivery . UI , thyroid hormones , and thyroid size are measured . Birth outcomes are recorded , such as gestational age at delivery , height , weight , and APGAR scores , and cord blood and heel stick blood ( < 72 h ) is collected from the child . Child development is assessed at 6 weeks of age using the Neonatal Behavioral Assessment Scale ( NBAS ) , and at 12 and 24 months of age using the Bayley Scales of Infant Development . The outcomes of these trials will contribute importantly to the evidence base for iodine supplementation of pregnant women living in areas of mild iodine deficiency OBJECTIVE Denmark was an area of iodine deficiency , and m and atory iodine fortification of table salt and salt in bread ( 13 p.p.m . iodine ) was initiated in 2000/2001 . The Danish investigation on iodine intake and thyroid disease ( DanThyr ) is the monitoring of the iodine fortification program . DESIGN AND METHODS DanThyr consists of three main parts : a study of population cohorts initialized before ( n=4649 ) and after ( n=3570 ) iodization of salt  , a prospect i ve identification of incident cases of overt hyper- and hypothyroidism in a population of around 550,000 people since 1997 , and compilation of data from the national registers on the use of thyroid medication , thyroid surgery , and radioiodine therapy . Studies were carried-out in parallel in subcohorts living in areas with differences in iodine content of ground water . RESULTS The study showed profound effects of even small differences in iodine intake level on the prevalence of goiter , nodules , and thyroid dysfunction . Mild and moderate iodine deficiency was associated with a decrease in serum TSH with age . Other environmental factors were also important for goiter development ( increase in risk , smoking and pregnancy ; decrease in risk , oral contraception and alcohol consumption ) , and the individual risk depended on the genetic background . Environmental factors had only a minor influence on the prevalence of thyroid autoantibodies in the population . There were more cases of overt hypothyroidism in mild than in moderate iodine deficiency caused by a 53 % higher incidence of spontaneous ( presumably autoimmune ) hypothyroidism . On the other h and , there were 49 % more cases of overt hyperthyroidism in the area with moderate iodine deficiency . The cautious iodine fortification program , aim ing at an average increase in iodine intake of 50 mug/day has been associated with a 50 % increase in incidence of hyperthyroidism in the area with the most severe iodine deficiency . The incidence is expected to decrease in the future , but there may be more cases of Graves ' hyperthyroidism in young people . CONCLUSION A number of environmental factors influence the epidemiology of thyroid disorders , and even relatively small abnormalities and differences in the level of iodine intake of a population have profound effects on the occurrence of thyroid abnormalities . Monitoring and adjustment of iodine intake in the population is an important part of preventive medicine CONTEXT Iodine deficiency in utero impairs fetal growth , but the relationship between iodine deficiency and postnatal growth is less clear . OBJECTIVE The objective of the study was to determine whether iodine repletion improves somatic growth in iodine-deficient children and investigate the role of IGF-I and IGF binding protein (IGFBP)-3 in this effect . DESIGN , PARTICIPANTS , AND INTERVENTIONS Three prospect i ve , double-blind intervention studies were done : 1 ) in a 10-month study , severely iodine-deficient , 7- to 10-yr-old Moroccan children ( n = 71 ) were provided iodized salt and compared with children not using iodized salt ; 2 ) in a 6-month study , moderately iodine-deficient , 10- to 12-yr-old Albanian children ( n = 310 ) were given 400 mg iodine as oral iodized oil or placebo ; 3 ) in a 6-month study , mildly iodine-deficient 5- to 14-yr-old South African children ( n = 188 ) were given two doses of 200 mg iodine as oral iodized oil or placebo . At baseline and follow-up , height , weight , urinary iodine ( UI ) , total T4 ( TT4 ) , TSH , and IGF-I were measured ; in Albania and South Africa , IGFBP-3 was also measured . RESULTS In all three studies , iodine treatment increased median UI to more than 100 microg/liter , whereas median UI in the controls remained unchanged . In South Africa , iodine repletion modestly increased IGF-I but did not have a significant effect on IGFBP-3 , TT4 , or growth . In Albania and Morocco , iodine repletion significantly increased TT4 , IGF-I , IGFBP-3 , weight-for-age z scores , and height-for-age z scores . CONCLUSION This is the first controlled study to clearly demonstrate that iodine repletion in school-age children increases IGF-I and IGFBP-3 concentrations and improves somatic growth The occurrence of iodine-induced hyperthyroidism ( IIH ) has been reported after iodine supplementation from clinics and hospitals , but not following an epidemiologic survey . We studied the prevalence of thyroid derangement in a population following iodine supplementation . One yr after more than 75 % of the population had been consuming 40 ppm iodized salt ; information regarding history of endemic goiter and iodized salt production , distribution , consumption and monitoring were collected in four cities of the Islamic Republic of Iran . A total of 6048 subjects were r and omly selected . All subjects were assessed for size of goiter , and urinary iodine and serum T4 , T3 , TSH , anti-thyroglobulin and antithyroperoxide were measured . Before iodine supplementation , all four cities were areas of endemic goiter . The rate of household consumption of iodized salt was 50 , 75 and 90 % in 1994 , 1995 and 1996 , respectively . Ninety-one percent of the salt sample s contained 15–55 ppm iodide . Total goiter rate was 57 , 62 and 68 % ; median urinary iodine was 188 , 197 and 190 μg/l in the age groups of 6–18 , 19–40 and > 40 yr , respectively . Prevalence of clinical and sub clinical hyperthyroidism was 0.34 and 0.41 and those of clinical and sub clinical hypothyroidism were 0.51 and 1.07 % , respectively . Nine point eight and 18 % in the 19–40 yr age group and 17.6 and 25.6 % in > 40 yr old subjects had positive anti-thyroperoxidase and antithyroglobulin , respectively . This systemic epidemiologic study in an iodine deficient population showed that , following a well-executed iodine supplementation program , the occurrence of IIH is rare BACKGROUND In many developing countries , children are at high risk of both goiter and iron deficiency anemia . Iron deficiency adversely affects thyroid metabolism and may reduce the efficacy of iodine prophylaxis in areas of endemic goiter . OBJECTIVE The aim of this study was to determine whether iron supplementation in goitrous , iron-deficient children would improve their response to iodized salt . DESIGN We conducted a r and omized , double-blind , placebo-controlled trial in 5 - 14-y-old children in Côte d'Ivoire . Goitrous , iron-deficient children ( n = 166 ) consuming iodized salt ( 10 - 30 mg I/kg salt at the household level ) were supplemented with either iron ( 60 mg Fe/d , 4 d/wk for 16 wk ) or placebo . At 0 , 1 , 6 , 12 , and 20 wk , we measured hemoglobin , serum ferritin , serum transferrin receptor , whole-blood zinc protoporphyrin , thyrotropin , thyroxine , urinary iodine , and thyroid gl and volume ( by ultrasonography ) . RESULTS Hemoglobin and iron status at 20 wk were significantly better after iron treatment than after placebo ( P < 0.05 ) . At 20 wk , the mean reduction in thyroid size in the iron-treated group was nearly twice that in the placebo group ( x + /- SD percentage change in thyroid volume from baseline : -22.8 + /- 10.7 % compared with -12.7 + /- 10.1 % ; P < 0.01 ) . At 20 wk , goiter prevalence was 43 % in the iron-treated group compared with 62 % in the placebo group ( P < 0.02 ) . There were no significant differences between groups in whole-blood thyrotropin or serum thyroxine at baseline or during the intervention . CONCLUSIONS Iron supplementation improves the efficacy of iodized salt in goitrous children with iron deficiency . A high prevalence of iron deficiency among children in areas of endemic goiter may reduce the effectiveness of iodine prophylaxis The benefits of iodine supplements during pregnancy remain controversial in areas with a mild-to-moderate iodine deficiency . The aim of the present study was to determine the effect of improving iodine intakes , with iodised salt ( IS ) or iodine supplements , in pregnant Spanish women . A total of 131 pregnant women in their first trimester were r and omly assigned to three groups : ( 1 ) IS in cooking and at the table , ( 2 ) 200 μg potassium iodide (KI)/d or ( 3 ) 300 μg KI/d . No differences were found in thyroid-stimulating hormone ( TSH ) , free thyroxine ( FT4 ) , free triiodothyronine ( FT3 ) or thyroid volume ( TV ) between the three groups . Regardless of the group in which women were included , those who had been taking IS for at least 1 year before becoming pregnant had a significantly lower TV in the third trimester ( P= 0.01 ) and a significantly higher urinary iodine in the first ( 173.7 ( sd 81.8 ) v. 113.8 ( sd 79.6 ) μg/l , P= 0.001 ) and third trimesters ( 206.3 ( sd 91.2 ) v. 160.4 ( sd 87.7 ) μg/l , P= 0.03 ) . Also , no differences were seen in TSH , FT4 or FT3 . Children 's neurological development was not significantly associated with the consumption of IS for at least 1 year before becoming pregnant and no differences were found according to the treatment group . In conclusion , in pregnant women with insufficient iodine intake , the intake of IS before becoming pregnant was associated with a better maternal thyroid function . The form of iodide intake was not associated with maternal thyroid function or children 's neurological development OBJECTIVE In many developing countries , children are at high risk for both goiter and anemia . Iron ( Fe ) deficiency adversely effects thyroid metabolism and reduces efficacy of iodine prophylaxis in areas of endemic goiter . The study aim was to determine if co-fortification of iodized salt with Fe would improve efficacy of the iodine in goitrous children with a high prevalence of anemia . DESIGN AND METHODS In a 9-month , r and omized , double-blind trial , 6 - 15 year-old children ( n=377 ) were given iodized salt ( 25 microg iodine/g salt ) or dual-fortified salt with iodine ( 25 microg iodine/g salt ) and Fe ( 1 mg Fe/g salt , as ferrous sulfate microencapsulated with partially hydrogenated vegetable oil ) . RESULTS In the dual-fortified salt group , hemoglobin and Fe status improved significantly compared with the iodized salt group ( P<0.05 ) . At 40 weeks , the mean decrease in thyroid volume measured by ultrasound in the dual-fortified salt group ( -38 % ) was twice that of the iodized salt group ( -18 % ) ( P<0.01 ) . Compared with the iodized salt group , serum thyroxine was significantly increased ( P<0.05 ) and the prevalence of hypothyroidism and goiter decreased ( P<0.01 ) in the dual-fortified salt group . CONCLUSION Addition of encapsulated Fe to iodized salt improves the efficacy of iodine in goitrous children with a high prevalence of anemia BACKGROUND The long-term goal of salt iodization is elimination of iodine deficiency and reduction of the goiter rate to < 5 % in school-aged children . Normalization of the goiter rate probably indicates disappearance of iodine deficiency disorders as a public health problem . However , thyroid size may not return to normal for months or years after correction of iodine deficiency . OBJECTIVE We described the time course and pattern of changes in thyroid size and goiter rate in response to the introduction of iodized salt in an area of severe endemic goiter . DESIGN In a 5-y prospect i ve study , we measured thyroid size by ultrasonography and urinary iodine and thyroid hormone concentrations in schoolchildren 6 mo before the introduction of iodized salt  and annually for 4 y thereafter . RESULTS Four years after the introduction of iodized salt and normalization of the median urinary iodine concentration , mean thyroid size had decreased 56 % ( P < 0.0001 ) . However , 29 % of the children remained goitrous , with a significant age shift in the distribution of goiter . At baseline , the goiter rate was significantly higher in younger ( age : 5 - 9 y ) than in older ( age : 10 - 14 y ) children ( P < 0.0001 ) . At 2 , 3 , and 4 y after salt iodization , the goiter rate was significantly higher in the older than in the younger children ( at 4 y : 52 % compared with 19 % ) , and the difference increased with time ( P < 0.0001 ) . CONCLUSION The goiter rate in school-aged children may remain sharply elevated for up to 4 y after successful introduction of iodized salt , primarily because of persistent goiter in older children OBJECTIVE A prospect i ve r and omized trial was performed to assess the usefulness of iodine supplementation in the prevention of goiter in pregnant women living in marginally iodine-deficient areas . DESIGN Eighty-six pregnant women were recruited and r and omized in two groups and treated daily for up to six months after delivery with 200 microg iodide ( group A ) or 50 microg iodide ( group B ) . Sixty-seven women ( 32 in group A and 35 in group B ) completed the study . METHODS Thyroid volume ( TV ) , thyroid functional parameters and urinary iodine concentration were determined in all subjects at booking , at the 18th-26th , and the 29th-33rd week of gestation , and at the 3rd and 6th month after delivery . RESULTS A slight but not significant increase in TV during gestation was observed only in group B. After delivery a progressive decrease in TV was documented in both groups , the final TV being significantly reduced with respect to the initial volume in group A. No significant changes in serum free thyroid hormones and TSH concentrations were found during gestation in either group . Postpartum thyroiditis was observed in 5 women ( 2 in group A , 3 in group B ) . No side effects were seen . CONCLUSION The present data indicate that in marginally iodine-deficient areas , the administration of iodide is recommended in pregnancy and lactation . In the conditions of the present trial a dose of 50 microg iodide/day is a safe and effective measure in preventing an increase in TV during pregnancy but a dose of 200 microg iodide/day appeared to be more effective without inducing side effects and without enhancing the frequency of post-partum thyroiditis The prevalence of iodine deficiency disorders and the thyroid status of the population were studied in an endemic goitre area in Algeria . After oral administration of lipiodol ( 0.5 ml ) , three treated groups of mother-newborn couples were compared to an untreated group : group A , mothers treated 1 - 3 months before conception ; group B , mothers treated during the first month of pregnancy ; group C , mothers treated during the third month of pregnancy . Untreated mothers were used as a control ( group D ) . After lipiodol treatment , all newborn babies and mothers were clinical ly euthyroid . All tested newborn babies were full term and no goitre was observed in the four groups . In the mothers , goitre prevalence and thyrotrophin levels decreased significantly , whereas maternal milk and urinary iodine and serum-free thyroxine levels were significantly higher after treatment . The rate of prematurity , stillbirths and abortions in the treated groups was reduced when compared to the untreated group , whereas placental and birth weights were significantly higher . In group D two cases of neonatal hypothyroidism were detected . Their re-evaluation confirmed that hypothyroidism was transient . Groups A , B and C were statistically different from group D with regard to neonatal thyrotrophin and thyroxine . Positive correlations were found between neonatal thyroxine and birth weights and placental weights on the one h and , and maternal urinary iodine and free thyroxine on the other . Consequently , these data indicate that oral administration of lipiodol before or during the first trimester of pregnancy normalizes thyroid function in newborn babies and mothers , increases placental and birth weight and reduces the frequency of iodine deficiency disorders . ( ABSTRACT TRUNCATED AT 250 WORDS During pregnancy complex changes of maternal thyroid function occur and they are influenced by the maternal iodine supply . It has been demonstrated that with decreasing iodine supply maternal goiter and hypothyroxinemia as well as fetal and neonatal hypothyroidism become more prevalent . Therefore iodine supplementation during pregnancy is now strongly recommended also in areas of moderate iodine deficiency . To monitor the success of iodine supplementation and its theoretical risk of increasing the frequency of thyroid autoantibodies , we have investigated the thyroid volume , thyroid function , urinary iodine excretion and antibodies to thyroid peroxidase at 10 - 12 weeks of gestation and postpartum in 38 mothers receiving 300 micrograms potassium iodide/day and in 70 mothers without iodine supplementation .  In all of their newborns thyroid volume was determined by ultrasound . The thyrotropin ( TSH ) levels and antibodies to thyroid peroxidase ( TPO-ab ) in the neonates were measured in dried blood spots on filter paper from their newborn screening . Urinary iodine excretion was increased significantly after iodine supplementation in mothers ( p < 0.001 ) and their newborns ( < 0.05 ) . No hypo- or hyperthyroidism was observed in the mothers or newborns . Interestingly , no difference of maternal thyroid volumes was observed between the two groups after pregnancy , but the volumes of the thyroid gl and s in newborns of mothers who received iodine were significantly ( p < 0.004 ) lower ( 0.7 + /- 0.4 ml ) than in the control group ( 1.5 + /- 1.1 ml ) . There was no change in the frequency of TPO-ab in either group after pregnancy . In four mothers transplacental passage of these antibodies was documented by positive measurement in the blood sample of the newborn . This study documents that iodine supplementation during pregnancy in an area of moderate iodine deficiency results in a lower size of neonatal thyroid volume and that this supplementation was not accompanied by an increase in the frequency of TPO-ab
REVIEW ERS ' CONCLUSIONS Despite most of the included studies being of low quality , the results suggest that iodine supplementation , especially iodised oil , is an effective means of decreasing goitre rates and improving iodine status in children .
Indications of positive effects on physical and mental development and mortality were seen , although results were not always significant .
Adverse effects were generally minor and transient .
BACKGROUND Iodine deficiency is the main cause of potentially preventable mental retardation in childhood , as well as causing goitre and hypothyroidism in people of all ages .
It is still prevalent in large parts of the world .
OBJECTIVES To assess the effects of iodine supplementation overall , and of different forms and dosages of iodine supplementation separately , in the prevention of iodine deficiency disorders in children .