Maternal homocysteine and related B vitamins as risk factors for low birthweight.

Abstract

We designed a large prospective study to explore the relationship between maternal homocysteine concentrations and related B vitamins and birthweight. Blood was sampled from pregnant women at 30-34 weeks of gestation and their newborn infants (n = 366). Concentrations of all analytes were higher in umbilical cord compared with maternal samples. Birthweight was related negatively to maternal homocysteine (r = -0.12) but not related to maternal cobalamin, methylmalonic acid, and folate (r = 0.02, r = 0.06, and r = 0.04, respectively). Regression analysis revealed smoking (beta = -313; 95% confidence interval [CI], -479 to -149), gestational age (beta = 150; 95% CI, 118-182), female sex (beta = -146; 95% CI, -256 to -35), and parity (beta = 104; 95% CI, 37-171) as strong determinants of birthweight. Maternal homocysteine, cobalamin, methylmalonic acid, and folate were not determinants of birthweight in multivariate analysis. Maternal homocysteine and B vitamins are not related to birthweight in a multivariate model that was adjusted for potential confounders.