The aim of this audit was to evaluate the effect of the introduction of biochemical screening for Downs syndrome (triple test i.e., serum alphafetoprotein [AFP], human chorionic gonadotrophin [hCG], and unconjugated oestriol [uE3] on amniocentesis at Whipps Cross Hospital.

BACKGROUND

Biochemical tests of fetal well-being such as placental hormone levels have not always shown direct benefits for mothers and babies.

OBJECTIVE

The objective of this review was to assess the effects of measuring placental hormone levels during high risk pregnancies.

METHODS

We searched the Cochrane Pregnancy and Childbirth Group trials register and MEDLINE. We also contacted study authors.

METHODS

Adequately controlled trials comparing availability with no availability of hormone placental tests in high risk pregnancy.

METHODS

Trial quality was assessed and data were extracted by two reviewers and this was checked by a colleague. Study authors were contacted for additional information.

RESULTS

Two trials involving 3355 women were included. Methodological quality of the trials was acceptable, but results for only 230 out of 2733 women (abnormal hormone levels) were available from one trial. One trial compared oestriol levels reported promptly with levels measured but not reported. The overall perinatal mortality rate was 30.5 per 1000 live births weighing 500 grams or more. No beneficial effects of oestriol measurement on fetal outcome could be identified (odds ratio of perinatal death 0.87, 95% confidence interval 0.35 to 2.18). For abnormal test results only, the reported oestriol group showed a statistically non-significant trend to less perinatal mortality (odds ratio 0.48, 95% confidence interval 0.15 to 1.60). The other trial compared human placental lactogen measurements reported promptly with measurements not reported until after pregnancy. For abnormal test results, the reported group showed significantly less perinatal mortality with four (3.4%) deaths compared to 17 (15%) in the control group (odds ratio 0.25, 95% confidence interval 0.10 to 0.61). Data from normal test results was not available for this trial.

CONCLUSIONS

The measurement of human placental lactogen levels may be of some value in high risk pregnancies, but there is not enough evidence to evaluate the use of hormone placental tests generally.

Prenatal screening using the maternal serum markers alpha-fetoprotein, human chorionic gonadotropin, and unconjugated oestriol was investigated in a native Japanese population. Comparison with a Caucasian U.S. population revealed differences which led to modification of the generally used equations for risk calculations. Prenatal screening was shown to be clinically useful.