An analysis of the utility of plasma immunoreactive estrogen measurements in determining delivery time of gravidas with a fetus considered at high risk.
Although maternal estrogen excretion and plasma estrogen levels are widely used to assess fetal health, the utility of these tests in lowering perinatal mortality rates has not been established. In order to ascertain if, with the help of plasma immunoreactive estrogen measurements, a reduction in perinatal deaths could be achieved, a population of women with a fetus at high risk were randomly divided into two groups and studied prospectively: in 315 gravidas, the estrogen results were reported (Group A); in 307, they were not reported (Group B). Nine perinatal deaths occurred in Group A, 10 in Group B. Ten Group B women whose infant ultimately did well would have been delivered 28 days or more prematurely if management had been based solely on the basis of abnormal immunoreactive estrogen levels. Measurement of estrogen levels is of little value in management of women with a fetus at risk; it may even lead to erroneous premature delivery.
The available trial data do not support the use of (o)estriol estimation in high-risk pregnancies. The single small trial available does not have the power to exclude a beneficial effect but this is probably of historical interest since biochemical testing has been superseded by biophysical testing in antepartum fetal assessment.