Predictive value of hormone determinations in the first half of pregnancy

Abstract

In a prospective randomized study serial hormone determinations (beta-hCG, HPL, P, 17-OHP, E2 and E3) were performed with 1125 pregnant women from the detection of pregnancy until delivery (n = 994) or abortion (n = 131). In 605 women carrying to term blood sampling started before the 16th wk of gestation, while 389 patients were admitted to hospital between the 16th and 20th wk of gestation. The first value of most of the hormone determinations at the time of diagnosis of pregnancy before the 16th wk was normal in more than 90% (beta-hCG 95%, P 94%, E3 94%, E2 92%, HPL 64%). In the case of women with abortion the first hormone determination was low in more than 50% (beta-hCG 51%, P 56%, E3 54%, E2 62%, HPL 62%). The predictive value was highest for beta-hCG (75%) and E2 (70%) and lowest for HPL (18%). In 249 women with threatened abortion blood samples were obtained at the first days of bleeding. At this time the highest sensitivity in detecting early abortions (before the 16th wk of pregnancy) was 82% for E2, followed by beta-hCG 74%, E3 65%, P 63%, 17-OHP 52% and HPL 34% (n = 112). In late abortion (after the 16th wk of pregnancy, n = 19) the sensitivity of all methods tested was below 40%. In the case of women with bleeding and continuation of pregnancy (n = 118) normal values were found in 95% by P, 94% by beta-hCG, 93% by HPL and E3, and 83% by 17-OHP respectively. Serial determinations in women with abortion revealed that in a normal population trophoblastic disorders with reduced beta-hCG concentrations were most common. Of the remaining patients with normal beta-hCG concentrations every third woman had low P or E2 values. The combined determination of all hormones allowed conclusions to be drawn on the cause of pregnancy failure. It could be established that prior to the 6th wk of pregnancy the determination of beta-hCG was most valuable. From the 7th wk onwards the measurement of E2 or E3 showed the highest sensitivity. Between the 11th and 14th wk of pregnancy the discriminating potency of all methods tested was equally high. After the 14th wk of pregnancy hormone determinations were of little diagnostic value.