Occurrence of molar pregnancy in patients undergoing elective abortion: comparison with other clinical presentations.

Clinical data of molar pregnancies found in women undergoing elective abortion (group 1, n = 39) were compared to those of molar pregnancies in women who experienced spontaneous abortions (group 2, n = 157) and women in whom molar pregnancy was discovered before symptoms of spontaneous abortion were evident (group 3, n = 209). Group 1 women were younger and experienced uterine evacuation at an earlier stage of amenorrhea than groups 2 and 3. Group 3 had larger uteri at evacuation and longer intervals of positive tests for the beta-subunit of human chorionic gonadotropin during the postmolar phase as compared with groups 1 and 2. On the basis of available provincial data for the number of elective abortions, the estimated incidence of molar pregnancies in this population was 1:2,699. The presence of malignant gestational trophoblastic neoplasia was documented in a single patient in group 1. The incidence of malignant gestational trophoblastic neoplasia in this group was not significantly different from that in groups 2 and 3. Routine pathologic examination of the products of conception in women undergoing elective abortion coupled with routine assays of the beta-subunit of human chorionic gonadotropin when molar pregnancy is found can identify both noninvasive and invasive trophoblastic disease in these women.