Nutrient intake in women before conception and risks of anophthalmia and microphthalmia in their offspring

We previously explored associations between nutrients including folate and other macro and micronutrients and risks of anophthalmia or microphthalmia in the National Birth Defects Prevention Study. In the current study, we expand those previous results with larger sample sizes and conduct analyses with an additional diet quality index using more recent data.

The National Birth Defects Prevention Study is a population-based, multicenter case-control study of over 30 major birth defects, with estimated due dates from October 1997 to December 2011. Cases were 224 infants diagnosed with anophthalmia or microphthalmia. Controls were 11,109 live-born, nonmalformed infants randomly selected by each study center. Mothers completed a standardized, computer-assisted telephone interview between 6 weeks and 24 months after delivery. Mothers responded to a shortened food frequency questionnaire, assessing their nutrient intake for the year before pregnancy, and questions about periconceptional (2 months before to 2 months after conception) vitamin supplement use. Nutrient intake quartiles were based on the intake among controls.

Among vitamin supplement users, odds of anophthalmia/microphthalmia were decreased for women with intake levels in the highest quartile of folate (0.56, 95% confidence interval [CI] 0.32-0.98), magnesium (0.42, 95% CI 0.22-0.82), and vitamin E (0.50, 95% CI 0.29-0.89). Among women not reporting vitamin supplement use, the odds were significantly increased for beta-carotene (2.5, 95% CI 1.10-5.68) and decreased for retinol (0.37, 95% CI 0.19-0.73).

In this expanded analysis, we observed associations for a few nutrients, specifically forms of vitamin A. However, the heterogeneity of results by form and vitamin use necessitates further inquiry.