Search

Importance Prenatal folic acid supplements reduce the risk of neural tube defects in children, but it has not been determined whether they protect against other neurodevelopmental disorders. Objective To examine the association between maternal use of prenatal folic acid supplements and subsequent risk of autism spectrum disorders (ASDs) (autistic disorder, Asperger syndrome, pervasive developmental disorder–not otherwise specified [PDD-NOS]) in children. Design, Setting, and Patients The study sample of 85 176 children was derived from the population-based, prospective Norwegian Mother and Child Cohort Study (MoBa). The children were born in 2002-2008; by the end of follow-up on March 31, 2012, the age range was 3.3 through 10.2 years (mean, 6.4 years). The exposure of primary interest was use of folic acid from 4 weeks before to 8 weeks after the start of pregnancy, defined as the first day of the last menstrual period before conception. Relative risks of ASDs were estimated by odds ratios (ORs) with 95% CIs in a logistic regression analysis. Analyses were adjusted for maternal education level, year of birth, and parity. Main Outcome Measure Specialist-confirmed diagnosis of ASDs. Results At the end of follow-up, 270 children in the study sample had been diagnosed with ASDs: 114 with autistic disorder, 56 with Asperger syndrome, and 100 with PDD-NOS. In children whose mothers took folic acid, 0.10% (64/61 042) had autistic disorder, compared with 0.21% (50/24 134) in those unexposed to folic acid. The adjusted OR for autistic disorder in children of folic acid users was 0.61 (95% CI, 0.41-0.90). No association was found with Asperger syndrome or PDD-NOS, but power was limited. Similar analyses for prenatal fish oil supplements showed no such association with autistic disorder, even though fish oil use was associated with the same maternal characteristics as folic acid use. Conclusions and Relevance Use of prenatal folic acid supplements around the time of conception was associated with a lower risk of autistic disorder in the MoBa cohort. Although these findings cannot establish causality, they do support prenatal folic acid supplementation.

Previous studies have shown that low maternal weight, a diet low in certain fats, higher stress levels, and lower androgen levels are associated with fewer male births, but no association has been reported between maternal eating disorders and sex ratio at birth (defined as the proportion of male live births). This prospective, population-based, cohort study was conducted as part of the Norwegian Mother and Child Cohort Study. A total of 38,340 pregnant women at a median of 18.6 weeks gestation completed a questionnaire on eating behavior that reflected DSM IV criteria for four eating disorders: anorexia nervosa, binge eating disorder, bulimia nervosa, and eating disorders not otherwise specified-purging type (EDNOS-P). Estimates of the sex ratio at birth were determined for women with singleton live births and eating disorder diagnoses. Poisson regression analyses were used to estimate unadjusted and adjusted proportions and ratios for factors known to affect the sex ratio at birth, including mother's age, marital status, prepregnancy body mass index (BMI), maternal education, lifetime smoking status, income, gestational age, and parity. Compared to a reference group, unadjusted analyses showed that proportions of male live births were 10% lower for mothers with anorexia nervosa and 8% lower for mothers with bulimia nervosa. A higher proportion of male births was found among mothers with maternal binge eating disorder (4%) and EDNOS-P (28%). Adjustment for covariates did not affect the results. These data suggest an association between the sex of offspring and maternal eating disorders. The specific eating disorder subtype appears to influence the direction of the effect.