Raised serum human chorionic gonadotrophin concentrations in hyperemesis gravidarum.

Serum human chorionic gonadotrophin (HCG) concentrations were determined by radioimmunoassay with an antiserum specific to HCG beta-subunit in 42 patients with hyperemesis gravidarum and 115 women with normal pregnancies. Mean concentrations (+/- SE of mean) were higher in the women with hyperemesis gravidarum at 7-8 weeks (40.8 +/- 5.2 IU/ml v 22.1 +/- 1.4 IU/ml; P less than 0.001), 9-11 weeks (38.1 +/- 2.3 IU/ml v 27.1 +/- 2.1 IU/ml; P less than 0.0025), and 12-14 weeks of gestation (35.9 +/- 4.2 IU/ml v 25.1 +/- 1.7 IU/ml; P less than 0.005), but there was no difference between the two groups at 15-20 weeks of gestation. In the hyperemesis gravidarum group primigravid women had a higher (P less than 0.005) mean HCG concentration (41.8 +/- 4.0 IU/ml) than multigravid women (32.2 +/- 2.3 IU/ml). The results suggest a causal relation between a high serum HCG concentration and hyperemesis gravidarum.