Hydatidiform mole in England and Wales 1973-83.

The number of cases of hydatidiform mole (HM) registered annually in England and Wales has risen since 1973 to 1.54 per 1000 live births in 1983. For women over 50 the risk per pregnancy was 411 times and for girls under 15 it was six times greater than that for women aged 25-29. 7.75% of patients had chemotherapy for invasive mole or choriocarcinoma. Patients who had had oxytocin-induced or prostaglandin-induced uterine evacuation or hysterotomy were more likely to need chemotherapy. Human chorionic gonadotropin (HCG) was undetectable by 56 days after evacuation in 42% of patients, none of whom required chemotherapy; a considerable reduction in follow-up time for this subgroup is proposed. For patients whose HCG values became normal more than 56 days after evacuation and stayed normal for 6 months the risk of recrudescent disease was 1 in 286. In subsequent pregnancies the risk of a second HM was 1 in 76 and that of a third was 1 in 6.5. 11 (0.2%) patients died, 2 from drug-resistant choriocarcinoma.