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 of mild thyroid dysfunctions are not yet well established. The aim was to evaluate the association of maternal thyroid function 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-based cohort study in four Spanish areas. Mid-gestation maternal serum and urine samples were gathered to determine thyroid-stimulating hormone (TSH), free thyroxine (fT4 ), and urinary iodine concentration (UIC). Thyroid status was defined according to percentile distribution as: euthyroid (TSH and fT4 >5th and <95th percentiles); hypothyroxinaemia (fT4 < 5 th percentile and TSH normal), hypothyroidism (TSH > 95th percentile and fT4 normal or <5th percentile), hyperthyroxinaemia (fT4 > 95 th percentile and TSH normal), and hyperthyroidism (TSH < 5 th percentile and fT4 normal or >95th percentile). Response variables were birthweight, small and large for gestational age (SGA/LGA), and preterm delivery. RESULTS: An inverse association of fT4 and TSH with birthweight was found, the former remaining when restricted to euthyroid women. High fT4 levels were also associated with an increased risk of SGA [odds ratio, 95% confidence interval (CI) 1.28 (95% CI 1.08, 1.51)]. Mean birthweight was higher in the hypothyroxinaemic group (ß = 109, P < 0.01). Iodine intake and UIC were not associated with birth outcomes. CONCLUSIONS: High maternal fT4 levels during the first half of pregnancy were related to lower birthweight and increased risk of SGA newborns, suggesting that maternal thyroid function may affect fetal growth, even within the normal range.

Absence of diabetes mellitus type 2 in obese children and adolescents in the north of Spain.

BACKGROUND: The worldwide epidemic of childhood obesity has been accompanied by an increase in the incidence of carbohydrate metabolism disorders. OBJECTIVE: To determine the prevalence of type 2 diabetes mellitus (T2DM) and other carbohydrate metabolism disorders in obese young people in the Basque Country (Spain). DESIGN: Prospective observational study. PATIENTS: We studied 136 obese Caucasian children and adolescents (body mass index ≥2 SDS above the mean). MEASUREMENTS: Their severity of obesity was classified as mild <3 SDS or moderate-to-severe ≥3 SDS. Data were collected on clinical and metabolic parameters; insulin resistance (IR) was calculated using the homeostasis model assessment, and an oral glucose tolerance test (OGTT) was carried out. RESULTS: T2DM was not found. Impaired glucose tolerance (IGT) was found in 9.6% of patients being higher in moderate-to-severe obesity (12.8% vs. 2.4%; p=0.048) and in patients with acanthosis nigricans (27.8% vs. 6.8%; p=0.016). No differences were detected by sex or pubertal development in metabolic results as a function of OGTT's response. IR (13.5%) was higher among those with moderate-to-severe obesity, in patients with acanthosis nigricans and was associated with other cardiovascular disease risk factors. CONCLUSIONS: We found no children with T2DM. The prevalence of IGT and IR was related to severity of obesity, to the association of acanthosis nigricans and was associated with cardiovascular risk.

Pre-natal exposure to dichlorodiphenyldichloroethylene and infant lower respiratory tract infections and wheeze.

The aim of our study was to examine whether pre-natal exposure to dichlorodiphenyldichloroethylene (DDE) increases the risk of lower respiratory tract infections (LRTIs) and wheeze in infants. The study is based on a birth cohort of 1,455 mother-child pairs. Maternal serum concentrations of DDE, polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) were measured during pregnancy. Parental reports on LRTI and wheeze were obtained when children were 12-14 months old. 35.4% of children developed at least one LRTI episode and 33.6% at least one wheezing episode during their first 12-14 months of life. Median DDE, PCBs and HCB concentrations were 116.3, 113.7 and 46.4 ng · g(-1) lipid, respectively. DDE concentrations were associated with LRTI risk (relative risk (RR) per 10% increase 1.11, 95% CI 1.00-1.22), also after adjustment for PCBs and HCB. In all quartiles of DDE exposure, the risk of LRTI was increased compared with the lowest quartile, but the increase was statistically significant only in the third quartile (RR 1.33, 95% CI 1.08-1.62). No association was observed for PCBs and HCB. Results were similar for wheeze. This study suggests that pre-natal DDE exposure is associated with a higher risk of LRTI and wheeze in infants independently of exposure to other organochlorine compounds.

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 muU/mL in women who consumed 200 microg or more of iodine supplements daily compared with those who consumed less than 100 microg/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 microg/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.

[Factors associated with the prevalence of hypovitaminosis D in pregnant women and their newborns]. / Factores asociados a la prevalencia de hipovitaminosis D en mujeres embarazadas y sus recién nacidos.

BACKGROUND: The finding of hypovitaminosis in pregnancy D has prompted the debate about its supplementation. The objective of the study was to measure the prevalence of hypovitaminosis D in mothers and newborns. METHODS: A one-year observational study was conducted including the measuring of vitamin D levels in mothers and in the umbilical cord blood of newborns. An analysis was made of the variables as regards maternal characteristics, delivery and sun exposure. RESULTS: Values lower than 20 ng/ml were found in 64.4% of 745 mothers and 41.3% of 560 newborns, and less than 30 ng/ml in 88.7% and 67.1%, respectively. Mean levels were higher in summer-autumn than in winter-spring (21.73 and 13.70 ng / ml in mothers and 29.04 and 20.49 ng/ml in cord), and higher in the umbilical cord than in the maternal plasma. Multiple pregnancies (OR: 6.29) and non-European origin (OR: 13.09) were risk factors for maternal hypovitaminosis, while maternal supplementation (OR: 0.19), physical activity (OR: 0.57), and sun exposure (OR: 0.46) had a preventive effect. CONCLUSIONS: The high rates of hypovitaminosis support the policy of giving dietary supplements to newborns. The high level of hypovitaminosis found supports the extension of screening and supplementation to all pregnant women, and not only to those with risk factors. The greater difference between mothers and newborns in seasons of low sun exposure can be interpreted as a protective effect.

Factores asociados a la prevalencia de hipovitaminosis D en mujeres embarazadas y sus recién nacidos / Factors associated with the prevalence of hypovitaminosis D in pregnant women and their newborns

Introducción: El hallazgo de hipovitaminosis D en el embarazo ha impulsado el debate acerca de su suplementación. El objetivo del estudio fue medir la prevalencia de hipovitaminosis D en gestantes y recién nacidos. Métodos: Se realizó un estudio observacional de un año de duración midiendo los niveles de vitamina D en madres y en sangre de cordón umbilical de recién nacidos. Se registraron variables relacionadas con las características de la madre, el parto y la exposición al sol. Resultados: Se encontraron valores menores de 20 ng/ml en el 64,4% de 745 madres y el 41,3% de 560 recién nacidos y menores de 30 ng/ml en el 88,7% y 67,1% respectivamente. Los niveles medios fueron más altos en verano-otoño que en invierno-primavera (21,73 y 13,70 ng/ml en madres y 29,04 y 20,49 ng/ml en cordón) y mayores en el cordón umbilical que en el plasma materno. Los embarazos múltiples (OR: 6,29) y el origen no europeo (OR: 13,09) fueron factores de riesgo de hipovitaminosis materna mientras que la suplementación materna (OR: 0,19), la actividad física (OR: 0,57) y la exposición al sol (OR: 0,46) tuvieron un efecto preventivo. Conclusiones: Las altas tasas de hipovitaminosis respaldan la política de dar suplementos dietéticos a los recién nacidos. El alto nivel de hipovitaminosis encontrado apoya la extensión del cribado y suplementación a todas las embarazadas y no solamente a aquellas con factores de riesgo. La mayor diferencia entre madre e hijo en las temporadas de baja exposición solar puede interpretarse como un efecto protector

Background: The finding of hypovitaminosis in pregnancy D has prompted the debate about its supplementation. The objective of the study was to measure the prevalence of hypovitaminosis D in mothers and newborns. Methods: A one-year observational study was conducted including the measuring of vitamin D levels in mothers and in the umbilical cord blood of newborns. An analysis was made of the variables as regards maternal characteristics, delivery and sun exposure. Results: Values lower than 20 ng/ml were found in 64.4% of 745 mothers and 41.3% of 560 newborns, and less than 30 ng/ml in 88.7% and 67.1%, respectively. Mean levels were higher in summer-autumn than in winter-spring (21.73 and 13.70 ng / ml in mothers and 29.04 and 20.49 ng/ml in cord), and higher in the umbilical cord than in the maternal plasma. Multiple pregnancies (OR: 6.29) and non-European origin (OR: 13.09) were risk factors for maternal hypovitaminosis, while maternal supplementation (OR: 0.19), physical activity (OR: 0.57), and sun exposure (OR: 0.46) had a preventive effect. Conclusions: The high rates of hypovitaminosis support the policy of giving dietary supplements to newborns. The high level of hypovitaminosis found supports the extension of screening and supplementation to all pregnant women, and not only to those with risk factors. The greater difference between mothers and newborns in seasons of low sun exposure can be interpreted as a protective effect

[Trihalomethane and haloacetic acid concentrations in drinking water and their estimated intake during pregnancy in the INMA cohort (Guipúzcoa, Spain)]. / Concentración de trihalometanos y de ácidos haloacéticos en el agua de consumo y estimación de su ingesta durante el embarazo en la cohorte INMA-Guipúzcoa (España).

OBJECTIVES: To report trihalomethane (THM) and haloacetic acid (HAA) concentrations in drinking water, assess variations in these concentrations depending on source and over time, and estimate individual intake during pregnancy. METHODS: Water taken from 33 representative points of the water supply network of the 25 municipalities in the study area was analyzed from 2006-2008. Water drinking habits were recorded using a questionnaire. RESULTS: Mean total THM concentrations were 16.9 µg/L (standard deviation, 7.9), while the mean value for the sum of concentrations of five HAA (monochloroacetic, dichloroacetic, tricholoroacetic, monobromoacetic, and dicromoacetic acids) was 10.9 µg/L (standard deviation, 4.9). Concentrations were lower in spring waters, which were only chlorinated, compared with dam waters, which were subject to a complete purification treatment: 8.8 µg/L vs 19.1 µg/L (p<0.01) and 8.2 µg/L vs 11.7 µg/L (p<0.01). Concentrations significantly increased with the number of deposits in the network and with their rechlorination and were higher in the summer and fall. Mean intakes of total THM and of the five HAA were lower in women supplied with spring water. Intakes differed depending on supply reservoir. CONCLUSIONS: Disinfection by-products in water are affected by water source, supply network structure, and annual season. The mean intake of these products varies depending on the source of drinking water. Mean intakes of all products were much lower than values recommended by the World Health Organization.

Concentración de trihalometanos y de ácidos haloacéticos en el agua de consumo y estimación de su ingesta durante el embarazo en la cohorte INMA-Guipúzcoa (España) / Trihalomethane and haloacetic acid concentrations in drinking water and their estimated intake during pregnancy in the INMA cohort (Guipúzcoa, Spain)

ObjetivosDescribir la concentración de trihalometanos (THM) y ácidos haloacéticos (AHA) del agua de consumo, valorar su variación espacio-temporal y estimar las ingestas individuales en el embarazo.MétodosEn los años 2006–2008 se analizó el agua en 33 puntos representativos de las redes de abastecimiento de los 25 municipios del área de estudio. Los hábitos de consumo de agua se obtuvieron mediante cuestionario.ResultadosLa media (desviación estándar) fue de 16,9μg/l (7,9) para el total de THM y de 10,9μg/l (4,9) para la suma de las concentraciones de cinco: monocloroacético, dicloroacético, tricloroacético, monobromoacético y dibromoacético (AHA5). Las concentraciones fueron menores en las aguas de manantial, sólo cloradas, que en las de embalse, sometidas a tratamiento completo de potabilización: 8,8μg/l frente a 19,1μg/l (p<0,01) y 8,2μg/l frente a 11,7μg/l (p<0,01). Los valores aumentan significativamente con el número de depósitos de la red y con la recloración, y son mayores en verano y en otoño. La ingesta media del total de THM y de AHA5 es menor en las mujeres que se abastecen de agua de manantial. Hay diferencias en la ingesta según el embalse de abastecimiento.ConclusionesEl origen del agua, la estructura de la red de distribución y la estación del año condicionan la cantidad de productos derivados de la desinfección en el agua. Las ingestas medias varían según el origen del agua, y para todos los productos están muy por debajo de los valores establecidos por la OMS (AU)

ObjectivesTo report trihalomethane (THM) and haloacetic acid (HAA) concentrations in drinking water, assess variations in these concentrations depending on source and over time, and estimate individual intake during pregnancy.MethodsWater taken from 33 representative points of the water supply network of the 25 municipalities in the study area was analyzed from 2006–2008. Water drinking habits were recorded using a questionnaire.ResultsMean total THM concentrations were 16.9μg/L (standard deviation, 7.9), while the mean value for the sum of concentrations of five HAA (monochloroacetic, dichloroacetic, tricholoroacetic, monobromoacetic, and dicromoacetic acids) was 10.9μg/L (standard deviation, 4.9). Concentrations were lower in spring waters, which were only chlorinated, compared with dam waters, which were subject to a complete purification treatment: 8.8μg/L vs 19.1μg/L (p<0.01) and 8.2μg/L vs 11.7μg/L (p<0.01). Concentrations significantly increased with the number of deposits in the network and with their rechlorination and were higher in the summer and fall. Mean intakes of total THM and of the five HAA were lower in women supplied with spring water. Intakes differed depending on supply reservoir.ConclusionsDisinfection by-products in water are affected by water source, supply network structure, and annual season. The mean intake of these products varies depending on the source of drinking water. Mean intakes of all products were much lower than values recommended by the World Health Organization (AU)