Levels and correlates of alpha-fetoprotein in normal pregnancies among Caucasian and Chinese women

Abstract

Alpha-fetoprotein has been suggested to have anti breast cancer properties both in adult life and in utero. We studied correlates of maternal serum alpha-fetoprotein levels in normal singleton pregnancies. This was a prospective study relying on women attending maternal units in major teaching hospitals in Boston, USA and Shanghai, China. Specifically, 212 Caucasian women in Boston, and 196 Asian women in Shanghai provided blood samples at the 16th and 27th gestational week. Maternal serum alpha-fetoprotein levels were measured and correlated with maternal and newborn parameters through multiple regression procedures, controlling for a set of potential confounders, including maternal levels of measured hormones. Alpha-fetoprotein was strongly inversely associated with maternal prepregnancy body mass index (-4.73 ng/l at the 27th week per 1 kg/m of body mass index, with 95% confidence intervals -7.09 to -2.36), whereas it was not related to parity, gender of offspring or birth weight. Duration of gestation was inversely associated with maternal alpha-fetoprotein levels, particularly among Caucasian women (-0.22 weeks per 60 ng/l of alpha-fetoprotein at the 27th week, with 95% confidence intervals -0.39 to -0.05). In normal pregnancies, maternal alpha-fetoprotein is inversely related to prepregnancy body mass index and appears to have a physiologic role on duration of gestation rather than on birth weight.