Association of birth by cesarean section with academic performance and intelligence in youth: A cohort study.

INTRODUCTION: It is suggested that birth by elective cesarean section (CS) reduces the risk of birth-related infant mortality and injury. Other studies suggest an increased risk of somatic immune-related diseases among children born by CS such as asthma, type 1 diabetes, and inflammatory bowel disease. The WHO Statement on Cesarean Section Rates 2015 described an increase in CS globally. The statement concluded that the effects of CS on social and psychological outcomes remain unclear and that more research is needed to fully understand the effects of CS, including effects on cognition and intelligence in the child. Therefore, we aimed to investigate the association between delivery by CS (elective and acute) and school performance and intelligence in youth. MATERIAL AND METHODS: This cohort study included all Danish live-born children in 1978-2000. We retrieved data regarding pregnancies, births, parents, school grades, and intelligence of the children from Danish registers and performed multiple imputations to avoid discarding data. The final cohort after exclusion comprised 1 408 230 children. Associations between CS and school graduation, grades, conscription attendance, and conscription intelligence scores were analyzed using univariate and multivariate logistic and linear regressions. RESULTS: Adjusted odds ratio with 95% CI of graduating from lower (LSE) and upper (USE) secondary education and of attending conscription were significantly lower in the CS group: LSE graduation: 0.87 (0.84-0.89), USE graduation: 0.93 (0.92-0.94), attending conscription: 0.95 (0.93-0.98). The CS group had significantly lower grade point averages (GPA) in LSE with adjusted differences in mean total GPA of -0.090 (-0.10 to -0.007), and mean core subject GPA of -0.098 (-0.11 to -0.08), in USE with total GPA difference of -0.091 (-0.11 to -0.075) and lower mean intelligence scores of -0.36 (-0.46 to -0.27) in adjusted linear models. A sub-analysis revealed lower chances of graduating LSE and USE when born by acute rather than elective CS. CONCLUSIONS: Chances of LSE and USE graduation and of attending conscription were significantly lower for children born by CS. However, even significant differences in mean GPAs and intelligence scores were very small, so performances when graduating school and attending conscription were comparable regardless of delivery mode.

Alcohol binge drinking in early pregnancy and the effect on fetal growth: a cohort study.

INTRODUCTION: Alcohol binge drinking is common in early pregnancy and is a well-established risk factor for subsequent child health. Yet, very few studies have investigated the effect on fetal growth. Furthermore, it has been speculated that the timing of binge drinking may be a determining factor for neonatal growth. The objective of this study was to assess the potential effect of binge drinking and different drinking patterns (timing and number of binge drinking episodes) in early pregnancy on fetal growth estimated by birthweight and birth length. MATERIAL AND METHODS: From 1 March to 31 August 2000, 1836 pregnant Danish women from Aarhus University Hospital and Fredericia Hospital were included in the study and interviewed around the early second trimester about their drinking habits during their pregnancy. Information on anthropometric measures at birth was obtained from the Danish Medical Birth Registry. The potential effect of binge drinking and different drinking patterns was estimated using a multivariate general linear regression model adjusted for potential confounders that were selected a priori based on the currently available scientific literature. RESULTS: The women who reported any binge drinking gave birth to children with a reduction in birth length of -0.02 cm (95% CI -0.23 to 0.18) and an increase in birthweight of 0.2 g (95% CI -42.8 to 43.2). The number of binge episodes and the timing of these episodes were also not associated with fetal growth. CONCLUSIONS: The study suggests that binge drinking and different drinking patterns in early pregnancy do not affect fetal growth.