Testing women's hormone levels during high-risk pregnancy has not been shown to benefit women or their babies.
The placenta provides nourishment for the baby in the womb (uterus) during pregnancy. It has been thought that testing women's hormone levels during pregnancy, might show how well the placenta is functioning and whether the baby is growing as would be expected. (Hormones are natural chemicals produced in the body.) The review of one trial (622 women) found some evidence that measuring (o)estriol levels in high-risk pregnancies did not affect the outcome of the pregnancy.
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the power to exclude a beneficial effect but this is probably of historical interest since biochemical testing has been superseded by biophysical testing in antepartum fetal assessment.
Biochemical tests of placental or feto-placental function were widely used in the 1960s and 1970s in high-risk pregnancies to try to predict, and thus try to avoid, adverse fetal outcome.
To assess the effects of performing biochemical tests of placental function in high-risk, low-risk, or unselected pregnancies.
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (10 May 2012).
Controlled trials (randomized or 'quasi-randomized') that compare the use of biochemical tests of placental function in pregnancy with non-use.
Trial quality was assessed and data were extracted by the review author.
A single eligible trial of poor quality was identified. It involved 622 women with high-risk pregnancies who had had plasma (o)estriol estimations. Women were allocated to have their (o)estriol results revealed or concealed on the basis of hospital record number (with attendant risk of selection bias). There were no obvious differences in perinatal mortality (relative risk (RR) 0.88, 95% confidence interval (CI) 0.36 to 2.13) or planned delivery (RR 0.97, 95% CI 0.81 to 1.15) between the two groups.