An analysis of the influences of maternal age, gestational age, contraceptive method, and the mode of primary treatment of patients with hydatidiform moles on the incidence of subsequent chemotherapy.

In relation to the total number of births in the United Kingdom there was an excess of hydatidiform moles arising in women over 34 years of age and possibly also under 15. The incidence of trophoblastic tumour requiring chemotherapy after hydatidiform mole was greatest in the 30 to 34 years age group and it was also high in the 20 to 24 years age group. This distribution appears to be influenced by the morphology of the moles, the mode of their removal and the use of oestrogens and progestogens in the post-evacuation period. The need for chemotherapy for trophoblastic tumour after evacuation of a hydatidiform mole was found to be two- to three-fold greater in patients who had undergone a medical induction, hysterectomy or hysterotomy compared with those whose hydatidiform moles had been evacuated by vacuum or surgical curettage, or who had aborted spontaneously. The increased risk of chemotherapy was most marked in the earlier weeks of gestation.