The use of lower of higher than recommended doses of folic acid supplements during pregnancy is associated with child attentional dysfunction at 4-5 years of age in the INMA Project

We assessed the association between the use of lower- and higher-than-recommended doses of folic acid supplements (FAs) during pregnancy and attentional function in boys and girls at age of 4-5. We analyzed data from 1329 mother-child pairs from the mother-child cohort INfancia y Medio Ambiente Project (INMA) study. Information on FAs use during pregnancy was collected in personal interviews at weeks 12 and 30, and categorized in <400, 400-999 (recommended dose), and ≥1000 μg/day. Child attentional function was assessed by Conners' Kiddie Continuous Performance Test. Multivariable regression analyses were used to estimate incidence rate ratios (IRR) and beta coefficients with 95% confidence intervals (CI). Compared to recommended FAs doses, the periconceptional use of <400 and ≥1000 μg/day was associated with higher risk of omission errors-IRR = 1.14 (95% CI: 1.01; 1.29) and IRR = 1.16 (95% CI: 1.02; 1.33), respectively. The use of FAs < 400 μg/day and ≥1000 μg/day was significantly associated with deficits of attentional function only in boys. FAs use < 400 μg/day was associated with higher omission errors with IRR = 1.22 and increased hit reaction time (HRT) β = 34.36, and FAs use ≥ 1000 μg/day was associated with increased HRT β = 33.18 and HRT standard error β = 3.31. The periconceptional use of FAs below or above the recommended doses is associated with deficits of attentional function in children at age of 4-5, particularly in boys

The use of lower or higher than recommended doses of folic acid supplements during pregnancy is associated with child attentional dysfunction at 4–5 years of age in the inma project

We assessed the association between the use of lower-and higher-than-recommended doses of folic acid supplements (FAs) during pregnancy and attentional function in boys and girls at age of 4–5. We analyzed data from 1329 mother-child pairs from the mother-child cohort INfancia y Medio Ambiente Project (INMA) study. Information on FAs use during pregnancy was collected in personal interviews at weeks 12 and 30, and categorized in <400, 400–999 (recommended dose), and ≥1000 µg/day. Child attentional function was assessed by Conners’ Kiddie Continuous Performance Test. Multivariable regression analyses were used to estimate incidence rate ratios (IRR) and beta coefficients with 95% confidence intervals (CI). Compared to recommended FAs doses, the periconceptional use of <400 and ≥1000 µg/day was associated with higher risk of omission errors—IRR = 1.14 (95% CI: 1.01; 1.29) and IRR = 1.16 (95% CI: 1.02; 1.33), respectively. The use of FAs < 400 µg/day and ≥1000 µg/day was significantly associated with deficits of attentional function only in boys. FAs use < 400 µg/day was associated with higher omission errors with IRR = 1.22 and increased hit reaction time (HRT) β = 34.36, and FAs use ≥ 1000 µg/day was associated with increased HRT β = 33.18 and HRT standard error β = 3.31. The periconceptional use of FAs below or above the recommended doses is associated with deficits of attentional function in children at age of 4–5, particularly in boys

Pre- and postnatal exposure to tobacco smoke and respiratory outcomes during the first year

The different role of prenatal and postnatal exposure to tobaccosmoke in respiratory outcomes in infants has not yet been clearly established.Our objective is to assess the effects of these exposures on the risk ofrespiratory outcomes during the first year of life of infants from a Spanishmulticenter cohort study. A total of 2506 wom en were monitored untildelivery. About 2039 infants made up the final population. The outcomes werecaused by the occurrence of the following: otitis, cough persisting for morethan 3 weeks, lower respiratory tract symptoms (wheezing or chestiness), andlower respiratory tract infections (bronchitis, bron chiolitis, or pneumonia).The relationship between prenatal and postnatal exposure and healthoutcomes was explored using logistic regression analys is. Maternal smokingduring pregnancy increased the odds for wheezing (OR: 1.41, 95% CI: 0.99 –2.01) and chestiness (OR: 1.46, 95% CI: 1.03–2.01). Postnatal exposure fromfathers was associated with otitis (OR: 1.25, 95% CI: 1.01–1.54). Passiveexposure at work of non-smoking mothers during pregnancy was related tocough (OR: 1.62, 95% CI: 1.05–2.51). Exposu re to tobacco smoke was relatedto a higher risk of experiencing respiratory outcomes in young infants.Prenatal exposure was that most clearly associated with the respiratory outcomes analyzed

Comparison of urinary iodine levels in women of childbearing age during and after pregnancy

Purpose Median urinary iodine concentration (UIC) is used to describe the iodine status of a population. However, the link between UIC and iodine intake may vary during pregnancy. The aim of this study was to compare UIC during and after pregnancy, adjusting for factors that affect iodine intake. Methods Two repeated measures of UIC and data on maternal iodine intake estimated through questionnaires were collected during pregnancy and 1–4 years after pregnancy in a subsample of women (n = 598) from a mother and child cohort study in Spain. Random-effects interval regression was used to assess the changes in UIC according to pregnancy status. Results Median UIC was similar during (133 μg/L) and after pregnancy (139 μg/L). After adjusting for iodised salt, iodine supplement consumption, and socio-demographic related variables, UIC was 24.0% (95% CI 11.3, 38.2) higher after than during pregnancy. This difference was maintained in a subsample of women with exhaustive information on diet (n = 291): 26.2%, 95% CI 10.3, 44.4. Conclusions In an iodine sufficient area for the general population, iodine excretion was lower during than after pregnancy when factors affecting iodine intake were controlled for. Current recommendations of median UIC during pregnancy are based on the equivalence between iodine intake and UIC estimated from studies in non-pregnant populations, which might lead to overestimation of iodine deficiency during gestation. Further studies should evaluate the equivalence between iodine intake and its urinary excretion during pregnancy

Maternal Thyroid Dysfunction during Gestation, Preterm Delivery, and Birthweight. The Infancia y Medio Ambiente Cohort, Spain

Background: Maternal clinical thyroid disorders can cause reproductive complications. However, the effects ofmild thyroid dysfunctions are not yet well established. The aim was to evaluate the association of maternal thyroidfunction during the first half of pregnancy with birthweight and preterm delivery.Methods: We analysed data on 2170 pregnant women and their children from a prospective population-basedcohort study in four Spanish areas. Mid-gestation maternal serum and urine samples were gathered to determinethyroid-stimulating hormone (TSH), free thyroxine (fT4), and urinary iodine concentration (UIC). Thyroid statuswas defined according to percentile distribution as: euthyroid (TSH and fT4>5th and 95th percentile and fT4normalor 95th percentile and TSH normal), and hyperthyroidism (TSH 95th percentile). Response variables were birthweight, small and large for gesta-tional age (SGA/LGA), and preterm delivery.Results: An inverse association of fT4and TSH with birthweight was found, the former remaining when restrictedto euthyroid women. High fT4levels were also associated with an increased risk of SGA [odds ratio, 95% confi-dence interval (CI) 1.28 (95% CI 1.08, 1.51)]. Mean birthweight was higher in the hypothyroxinaemic group(β=109, P < 0.01). Iodine intake and UIC were not associated with birth outcomes.Conclusions: High maternal fT4levels during the first half of pregnancy were related to lower birthweight andincreased risk of SGA newborns, suggesting that maternal thyroid function may affect fetal growth, even withinthe normal range

Iodine intake and maternal thyroid function during pregnancy

Background: An adequate iodine intake during pregnancy is essential for the synthesis of maternal thyroid hormones and normal brain development in the fetus. Scant evidence is available on the effects and safety of iodine supplementation during pregnancy in areas with adequate or mildly deficient iodine intake. We examined the association of maternal iodine intake and supplementation with thyroid function before 24 weeks of gestation in population-based samples from 3 different areas in Spain. Methods: A cross-sectional study of 1844 pregnant women (gestational age range 8-23 weeks) was carried out in 3 areas in Spain (Guipúzcoa, Sabadell, Valencia), during the period 2004-2008. We measured levels of free thyroxine and thyroid-stimulating hormone (TSH) in serum, iodine in a spot urine sample, and questionnaire estimates of iodine intake from diet, iodized salt and supplements. Adjusted associations were assessed by multiple linear regression and logistic regression analyses. Results: There was an increased risk of TSH above 3 μU/mL in women who consumed 200 μg or more of iodine supplements daily compared with those who consumed less than 100 μg/day (adjusted odds ratio = 2.5 [95% confidence interval = 1.2 to 5.4]). We observed no association between urinary iodine and TSH levels. Pregnant women from the area with the highest median urinary iodine (168 μg/L) and highest supplement coverage (93%) showed the lowest values of serum free thyroxine. (geometric mean = 10.09 pmol/L [9.98 to 10.19]). Conclusions: Iodine supplement intake in the first half of pregnancy may lead to maternal thyroid dysfunction in iodine-sufficient or mildly iodine-deficient populations. © 2009 by Lippincott Williams & Wilkins.Supported by grants from Instituto de Salud Carlos III (Red INMA G03/176 and CB06/02/0041), the Spanish Ministry of Health (FIS 03/1615, FIS 04/1509, FIS 04/1436, FIS 05/1079, FIS 06/1213, FIS06/0867), Ministerio Educacion y Ciencia (SAF2002-03508), the Generalitat de Catalunya-CIRIT 1999SGR 00241, Departamento de Sanidad-Gobiemo Vasco 2005111093, and Diputacion Foral de Gipuzkoa 06/004.Peer Reviewe

Maternal occupational exposure to chemicals and child cognitive function

Background: Limited data exist regarding child neurodevelopment in relation to maternal occupational exposure to endocrine-disrupting chemicals (EDCs). Methods: We included 1058 mother–child pairs from the INfancia y Medio Ambiente (INMA) project (2003–2008). Using a job-exposure matrix, exposure probability scores for ten EDC groups were assigned to each mother based on her longest held job during pregnancy. At the child’s 5-year visit, the McCarthy Scales of Children’s Abilities was administered, yielding the general cognitive index and scales for specific cognitive domains. We analyzed region-specific associations between EDC exposures and each outcome separately using adjusted linear regression and combined region-specific effect estimates using random-effects meta-analyses. Results: Approximately 24% of women were exposed to at least one EDC group, but exposure to most individual EDC groups was low (<5%). Maternal organic solvent exposure was associated with lower quantitative scores among children (−5.8 points, 95% confidence interval: −11.0, −0.5). Though statistically non-significant, exposures to polycyclic aromatic hydrocarbons, phthalates, alkylphenolic compounds, and miscellaneous chemicals were associated with poorer offspring performance for most or all cognitive domains. Conclusions: This study found limited evidence for a role of maternal occupational EDC exposures on child cognition. Further research is needed to better characterize exposures among pregnant workers. Impact: Using data from a prospective birth cohort, we help fill an important research gap regarding the potential consequences of work-related exposure to endocrine-disrupting chemicals (EDCs) among pregnant women on child neurodevelopment.We expand on existing literature—largely limited to pesticide and organic solvent exposures—by using a job-exposure matrix to estimate exposure to several EDC groups.We found limited evidence of an association between maternal occupational EDC exposure and children’s overall cognition.We did observe specific associations between exposure to organic solvents and lower quantitative reasoning scores