Comparison of lipids and apolipoproteins in amniotic fluid, neonatal urine, and cord serum

During the past two decades, major progress has been made in understanding the plasma lipid transport system. Such advances have shown that the metabolic fate of plasma lipids in the form of plasma lipoproteins are subject to specific regulatory controls dictated largely by their composition, quantity, specific surface apolipoproteins, and several lipolytic enzymes. The lipid and apoprotein composition of surfactant and its functional significance in the neonatal lung has also developed into a major area of investigation owing to its relationship by hyaline membrane disease and the accompanying morbidity and mortality. Since both systems share lipids as common constituents, it becomes important to define the composition of lipids and apoproteins in amniotic fluid because of their relationship to fetal lung maturity. In this review, the significance of amniotic fluid and cord serum apolipoprotein and lipid compositions are compared, and the origin or specific pulmonary and neonatal serum lipids are considered.