Human chorionic gonadotrophin β-subunit in normal and abnormal early pregnancy

Summary

A prospective study was carried out of 125 patients in early pregnancy. Ultrasound examination was performed on every patient to estimate gestational age and blood was taken for serum β-subunit human chorionic gonadotrophin (HCG) assay. The patients were divided into groups according to the outcome of the pregnancy. HCG levels in 39 successful pregnancies in which there had been bleeding did not differ from those in 40 normal pregnancies. There was no alteration in HCG levels during episodes of bleeding.

Thirty-two patients aborted spontaneously in the first trimester. These were divided into missed abortions (5) where fetal tissue was seen and an- embryonic pregnancies (27) where no fetal tissue was identified histologically. The average levels of HCG in these pregnancies were reduced, but the results of serial tests overlapped those for normal pregnancy. These findings may be explained by the histological presence of hydropic chorionic villi producing HCG in some cases of anembryonic pregnancy. This precludes the use of HCG estimation prognostically in the management of threatened abortion.

The HCG levels in the first 12 weeks of 7 pregnancies ending with spontaneous abortion in the middle trimester were normal.