Multiple marker second trimester serum screening for pre-eclampsia.

OBJECTIVE

To investigate whether an appropriate combination of maternal serum inhibin A, free beta-human chorionic gonadotropin (free beta-hCG), unconjugated estriol (uE3), and alpha-fetoprotein (AFP) may be an effective means of screening for pre-eclampsia in the second trimester of pregnancy.

SETTING

Women who attended an antenatal clinic in Oxford, from whom serum samples were stored, 19 of whom subsequently developed pre-eclampsia.

METHODS

Serum inhibin A, free beta-hCG, uE3, and AFP were measured in 32 serum samples collected from the 19 women who developed pre-eclampsia and, for each sample, in three control samples collected from women with unaffected pregnancies matched for gestational age and maternal age.

RESULTS

In pregnancies that developed pre-eclampsia the median inhibin A value was raised (1.7 multiples of the median (MoM) for unaffected pregnancies (95% confidence interval (95% CI) 1.1 to 2.7 MoM), the median free beta-hCG was raised (2.1, 1.4 to 3.3 MoM) and the median uE3 was lowered (0.8, 0.6 to 0.98 MoM) after 19 completed weeks of gestation and at least 2 weeks before the onset ofproteinuria. Values of AFP were similar in affected and unaffected pregnancies. Combining the values ofinhibin A, free beta-hCG, and uE3 to form a screening test would detect an estimated 55% of affected pregnancies with a false positive rate of 5%.

CONCLUSIONS

Inhibin A, free beta-hCG, and uE3 in combination may be a useful screening test during the second trimester for pre-eclampsia.