Maternal periconceptional folic acid supplementation and risk for fetal congenital genitourinary system defects

BackgroundTaking folic acid supplementation could reduce the risk of neural tube defects for offspring in the maternal periconceptional period, but the relationship between folic acid use and other birth defects remains unclear, such as genitourinary system birth defects.MethodsThe data from a Prenatal Health Care System and Birth Defects Surveillance System in Tongzhou, Beijing, China, were collected from 2013 to 2018. We adjusted for differences in characteristics between comparison groups using propensity score inverse probability weighting and assessed associations with Poisson regression modeling.ResultsA total of 65,418 live births and stillbirths were included, and there were 194 cases with congenital genitourinary defects among them. The prevalence of genitourinary system birth defects was 29.2 (34.9) per 10,000 for FA/MMFA users (nonusers). Compared to nonusers, FA/MMFA users had a lower risk for genitourinary system birth defects (adjusted risk ratio [aRR] 0.81, 95% confidence interval [CI] 0.67, 0.98), and for hypospadias (aRR 0.55, 95% CI 0.40, 0.76).ConclusionsFA or MMFA supplementation during the maternal periconceptional period could reduce the risk for genitourinary system birth defects in offspring. More mechanisms should be explored for the protective effect.ImpactFolic acid (FA) or multiple micronutrients containing folic acid (MMFA) supplementation during the maternal periconceptional period could reduce the risk for genitourinary system birth defects in offspring.Maternal FA/MMFA supplementation during the periconceptional period may reduce the risk for hypospadias.