A method for oestriol estimation in amniotic fluid and its use in the study of normal and abnormal pregnancy

A sensitive gas chromatographic method for the measurement of oestriol in amniotic fluid is described. The reliability of the method is discussed. The results obtained show that oestriol is the major oestrogen in amniotic fluid and near term is present mainly as glucosiduronate. The rate of increase in amniotic oestriol concentration accelerates as pregnancy progresses and the ultimate level reached correlates significantly with the weight of the newborn. The oestriol level in the amniotic fluid reflects the fetal condition, and there is a significant reduction in amniotic oestriol concentration in abnormal pregnancies, e.g., in anencephaly and severe Rh-isoimmunisation.