The role of maternal-fetal cholesterol transport in early fetal life: current insights.

The importance of maternal cholesterol as an exogenous cholesterol source for the growing embryo was first reported in studies of Smith-Lemli-Opitz syndrome. Although most of the fetus's cholesterol is synthesized by the fetus itself, there is now growing evidence that during the first weeks of life, when most organs develop, the fetus largely depends on maternal cholesterol as its cholesterol source. The maternal-fetal cholesterol transport mechanism, by transporters in both the yolk sac and placenta, is becoming better understood. This minireview summarizes current insights on maternal-fetal cholesterol transport based on in vitro and in vivo studies. As the prevalence of maternal diseases, such as diabetes, obesity, and the metabolic syndrome that adversely affect maternal cholesterol levels, is now rapidly reaching epidemic proportions, we urgently need to determine the impact of these maternal conditions on the developing human fetus.