Association between periconceptional maternal fish consumption and birth defects

Maternal fish consumption is useful in fetal development due to low saturated fat, high unsaturated fat, beneficial proteins and essential nutrients. However, fish consumption may expose the fetus to harmful environmental contaminants, which have been linked to neuro-developmental problems in human offspring and structural malformations in animal fetuses. The National Birth Defects Prevention Study (NBDPS) collects data on birth defects; maternal dietary history and socio-demographic characteristics. We used logistic regression and calculated odds ratios (OR) and their 95% confidence intervals (CI) to assess the relationship between periconceptional maternal fish consumption and the occurrence of birth defects in the NBDPS population. Adjusted odds ratios suggested that compared with mothers who ate fish less than once a month, mothers who ate 3-5oz of fish 1-3 times/month were significantly protected from oral clefts (OR=0.82, CI=0.73-0.93), anomalous pulmonary venous return (OR=0.54, CI=0.36-0.81) and anorectal atresia/stenosis (OR=0.78, CI=0.62-0.98). However, high levels of fish consumption increased risk for perimembranous ventricular septal defects (OR=1.25, CI=1.03-1.51) and amniotic band syndrome (OR=1.60, CI=1.01-2.55). Our findings suggest that women who are planning to become pregnant should be eating 3-5oz of fish 1-3 times per month to protect against birth defects; however it might confer risk to consume higher amounts.