Deficit of vitamin D in pregnancy and growth and overweight in the offspring.

BACKGROUND: Maternal vitamin D status during fetal development may influence offspring growth and risk of obesity; however, evidence in humans is limited. OBJECTIVE: To investigate whether maternal circulating 25-hydroxyvitamin D3 (25(OH)D3) concentration in pregnancy is associated with offspring prenatal and postnatal growth and overweight. METHODS: Plasma 25(OH)D3 concentration was measured in pregnant women (median weeks of gestation 14.0, range 13.0-15.0) from the INMA (INfancia y Medio Ambiente) cohort (Spain, 2003-2008) (n = 2358). Offspring femur length (FL), biparietal diameter (BPD), abdominal circumference (AC) and estimated fetal weight (EFW) were evaluated at 12, 20 and 34 weeks of gestation by ultrasound examinations. Fetal overweight was defined either as AC or as EFW ⩾ 90th percentile. Child's anthropometry was recorded at ages 1 and 4 years. Rapid growth was defined as a weight gain z-score of >0.67 from birth to ages 6 months and 1 year. Age- and sex-specific z-scores for body mass index (BMI) were calculated at ages 1 and 4 years (World Health Organization referent); infant's overweight was defined as a BMI z-score ⩾ 85th percentile. RESULTS: We found no association of maternal 25(OH)D3 concentration with FL and a weak inverse association with BPD at 34 weeks. Maternal deficit of 25(OH)D3 (<20 ng ml(-1)) was associated with increased risk of fetal overweight defined as AC ⩾ 90th percentile (odds ratio (OR) = 1.50, 95% confidence interval (CI): 1.01-2.21; P = 0.041) or either as EFW ⩾ 90th percentile (OR = 1.47, 95% CI: 1.00-2.16; P = 0.046). No significant associations were found with rapid growth. Deficit of 25(OH)D3 in pregnancy was associated with an increased risk of overweight in offspring at age 1 year (OR = 1.42, 95% CI: 1.02-1.97; P = 0.039); however, the association was attenuated at age 4 years (OR = 1.19, 95% CI: 0.83-1.72; P = 0.341). CONCLUSIONS: Vitamin D deficiency in pregnancy may increase the risk of prenatal and early postnatal overweight in offspring. Clinical trials are warranted to determine the role of vitamin D in the early origins of obesity.

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

The different role of prenatal and postnatal exposure to tobacco smoke in respiratory outcomes in infants has not yet been clearly established. Our objective is to assess the effects of these exposures on the risk of respiratory outcomes during the first year of life of infants from a Spanish multicenter cohort study. A total of 2506 women were monitored until delivery. About 2039 infants made up the final population. The outcomes were caused by the occurrence of the following: otitis, cough persisting for more than 3 weeks, lower respiratory tract symptoms (wheezing or chestiness), and lower respiratory tract infections (bronchitis, bronchiolitis, or pneumonia). The relationship between prenatal and postnatal exposure and health outcomes was explored using logistic regression analysis. Maternal smoking during 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 from fathers was associated with otitis (OR: 1.25, 95% CI: 1.01-1.54). Passive exposure at work of non-smoking mothers during pregnancy was related to cough (OR: 1.62, 95% CI: 1.05-2.51). Exposure to tobacco smoke was related to a higher risk of experiencing respiratory outcomes in young infants. Prenatal exposure was that most clearly associated with the respiratory outcomes analyzed.

Indoor and outdoor concentrations and determinants of NO2 in a cohort of 1-year-old children in Valencia, Spain.

UNLABELLED: Nitrogen dioxide (NO2) is produced from the exhausts of vehicles and gas appliances and is known to pose certain health risks. In this study, we characterize the exposure to this substance during the first year of life, which is an important period of development. To this end, we used passive samplers to measure indoor and outdoor NO2 levels for 2 weeks in the homes of 352 children. To compensate for the fact that NO2 levels were measured only once in each home, a correction factor was calculated to assign each child an outdoor NO2 exposure value for the first year of life. The outdoor NO2 concentrations were 26.1 microg/m(3) while those measured indoors averaged 18.0 microg/m(3). A multivariate linear regression analysis showed that the main determinants of outdoor NO2 levels were the degree of urbanization and the frequency of vehicle traffic at the location of the residence while for indoor NO2 levels the principal determinants were the type of cooking range and water heater present in the home, the season of the year, and both the country of origin and educational level of the mother. PRACTICAL IMPLICATIONS: Exposure to NO2 has been related to respiratory and other health problems among children. Precise identification of the main sources of both indoor and outdoor NO2 should shed light on appropriate intervention periods and methods. Our results indicate that while population density and traffic-related variables are the main determinants of outdoor NO2 levels, the use of gas appliances have the greatest impact on indoor levels. Strategies should thus be developed to reduce such exposure, especially with regard to reducing emissions from vehicle traffic.