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.

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.

Association between GIS-based exposure to urban air pollution during pregnancy and birth weight in the INMA Sabadell Cohort.

BACKGROUND: There is growing evidence that traffic-related air pollution reduces birth weight. Improving exposure assessment is a key issue to advance in this research area. OBJECTIVE: We investigated the effect of prenatal exposure to traffic-related air pollution via geographic information system (GIS) models on birth weight in 570 newborns from the INMA (Environment and Childhood) Sabadell cohort. METHODS: We estimated pregnancy and trimester-specific exposures to nitrogen dioxide and aromatic hydrocarbons [benzene, toluene, ethylbenzene, m/p-xylene, and o-xylene (BTEX)] by using temporally adjusted land-use regression (LUR) models. We built models for NO(2) and BTEX using four and three 1-week measurement campaigns, respectively, at 57 locations. We assessed the relationship between prenatal air pollution exposure and birth weight with linear regression models. We performed sensitivity analyses considering time spent at home and time spent in nonresidential outdoor environments during pregnancy. RESULTS: In the overall cohort, neither NO(2) nor BTEX exposure was significantly associated with birth weight in any of the exposure periods. When considering only women who spent < 2 hr/day in nonresidential outdoor environments, the estimated reductions in birth weight associated with an interquartile range increase in BTEX exposure levels were 77 g [95% confidence interval (CI), 7-146 g] and 102 g (95% CI, 28-176 g) for exposures during the whole pregnancy and the second trimester, respectively. The effects of NO(2) exposure were less clear in this subset. CONCLUSIONS: The association of BTEX with reduced birth weight underscores the negative role of vehicle exhaust pollutants in reproductive health. Time-activity patterns during pregnancy complement GIS-based models in exposure assessment.

Mortalidad materna en África / Maternal mortality in Africa

Los autores presentan en este informe la dramática situación de la salud materna en los países de África. De acuerdo con las estimaciones más recientes, en este continente muere anualmente cerca de medio millón de mujeres (1 muerte materna/min); un número importante de ellas (entre 3 y 4 millones) queda con fístulas genitourinarias invalidantes. Al contrario, en los países industrializados sólo se registran anualmente 2.500 muertes maternas (el 0,47% del total mundial) con una tasa de mortalidad materna (TMM) del 20/100.000. La situación es especialmente mala en los países del África subsahariana donde las distintas TMM superan los 1.000/100.000 nacidos vivos, con un riesgo de muerte materna durante toda la vida de 1/14 frente a 1/2.800 de los países desarrollados. El informe analiza las causas de muerte materna en el continente africano, las razones por las que se producen los 3 retrasos que las condicionan (retraso en la solicitud de ayuda, en llegar al hospital y en este último), así como las intervenciones necesarias para disminuir las elevadas TMM. Finalmente se presenta un plan integral, auspiciadopor la World Association of Perinatal Medicine (WAPM) y la International Academy of Perinatal Medicine (IAPM), que tiene por objetivo reducir en tres cuartas partes la TMM en África Central, de acuerdo con el espíritu de la Declaración de los Objetivos del Milenio de la Asamblea General de las Naciones Unidas

In this report, the authors describe the dramatic situation of maternal health in African countries. According to the most recent estimates, almost 1 million African women die each year (one maternal death per minute) and a significant proportion of these (between 3 and 4 million) have incapacitating genitourinary fistulae. In contrast, in industrialized countries, only 2,500 maternal deaths are registered yearly (0.47% of the total worldwide) with a maternal mortality ratio (MMR) of 20 per 100,000 live births. The situation is especially unfavorable in Sub- Saharan Africa, where the distinct MMR are higher than 1,000 per 100,000 live births, with a lifetime risk of maternal death of 1/14 compared with 1/2,800 in developed countries. This report analyzes the causes of maternal death in the African continent, the reasons for the three type of delay that affect these causes (delay in requesting help, delay in arriving at a hospital and delay in receiving medical attention after arrival), as well as the interventions required to reduce the elevated MMR. Finally, an Integral Plan, developed by the World Association of Perinatal Medicine (WAPM) and the International Academy of Perinatal Medicine (IAPM) is presented. This initiative aims to reduce theMMR in Central Africa by two-thirds, in agreement with the spirit of the «Declaration on the Millenium Development Goals» of the United Nations General Assembly

Reflexiones sobre la cesárea / Reflections on cesarean section

En este artículo se analiza la variabilidad de la tasa actual de las cesáreas y los motivos de su incremento, haciendo especial hincapié en las causas no médicas que influyen en el mismo, todo ello con el ánimo de inducir al lector a una reflexión sobre una manera de nacer que sustituye un proceso fisiológico por un procedimiento de cirugía mayor. El propósito de este artículo es aportar algunos argumentos y reflexiones, basados en la revisión de la bibliografía disponible, relacionados con la práctica de la cesárea

This article analyzes the changes in the current cesarean section rate and the causes for its increase, with special emphasis on the nonmedical reasons involved, in the attempt to induce the reader to reflect on a mode of delivery that substitutes a physiological process with a major surgical procedure. The purpose of the article is to provide certain arguments and reflections, based on a review of the available medical literature, concerning the performance of cesarean section