Head circumference and child ADHD symptoms and cognitive functioning: results from a large population-based cohort study.

The aim of this study is to understand the association between prenatal, newborn and postnatal head circumference (HC) and preschool neurodevelopment in a large population-based birth cohort. The INMA project followed 1795 children from 12 weeks of pregnancy to preschool years. HC measurements were carried out prospectively, and following a standardized protocol during pregnancy (12, 20 and 34 weeks), birth, and child ages of 1-1.5 and 4 years old; and z-scores were further estimated. Prenatal head growth was assessed using conditional z-scores between weeks 12-20 and 20-34. Several neuropsychological tests [MSCA (cognition), CPT (attention)] and behavioral rating scales [DSM-IV-ADHD, CAST (autism), CPSCS (social competence)] were carried out during the last follow-up (5 years old). Multivariable models adjusted for family and child characteristics were applied to analyze associations between HC and neurodevelopment. In fully adjusted models, prenatal HC and head growth showed little or no associations with the neurodevelopment outcomes. Independent associations were observed between HC z-scores at birth, 1-1.5 years and 4 years and MSCA global cognitive scores and DSM-IV inattention symptoms. Specifically, z-score at birth was positively associated with general cognitive scores [ß 1.22, 95% confidence interval (CI) 0.59, 1.85], and we observed a protective association with ADHD-DSM-IV total symptoms, mean ratio (MR) 0.85 (0.75, 0.96). Prenatal HC and head growth measurements gave little information about child cognitive abilities and behavior at preschool years. However, HC at birth and early childhood was positively associated with a range of neuropsychological outcomes, including protective associations with ADHD symptoms.

Maternal vitamin D status in pregnancy and risk of lower respiratory tract infections, wheezing, and asthma in offspring.

BACKGROUND: Adequate vitamin D status in mothers during pregnancy may influence the health status of the child later in life. We assessed whether maternal circulating 25-hydroxyvitamin D (25[OH]D) concentrations in pregnancy are associated with risk of lower respiratory tract infections, wheezing, and asthma in the offspring. METHODS: Data were obtained from 1724 children of the INfancia y Medio Ambiente (INMA) Project, a population-based birth cohort study. Maternal circulating 25(OH)D concentrations were measured in pregnancy (mean gestational age = 12.6 [SD = 2.5] weeks). When the child was age 1 year, parents were asked if their child had a physician-confirmed history of lower respiratory tract infections or a history of wheezing. The questions about wheezing were repeated annually thereafter. Asthma was defined as parental report of doctor diagnosis of asthma or receiving treatment at the age of 4-6 years or wheezing since the age of 4 years. RESULTS: The median maternal circulating 25(OH)D concentration in pregnancy was 29.5 ng/mL (interquartile range, 22.5-37.1 ng/mL). After multivariable adjustment, there was a trend for an independent association between higher levels of maternal circulating 25(OH)D levels in pregnancy and decreased odds of lower respiratory tract infections in offspring (for cohort- and season-specific quartile Q4 vs. Q1, odds ratio = 0.67 [95% confidence interval = 0.50-0.90]; test for trend, P = 0.016). We found no association between 25(OH)D levels in pregnancy and risk of wheezing at age 1 year or 4 years, or asthma at age 4-6 years. CONCLUSIONS: Higher maternal circulating 25(OH)D concentrations in pregnancy were independently associated with lower risk of lower respiratory tract infections in offspring in the first year of life but not with wheezing or asthma in childhood.