GYNECOLOGIC ONCOLOGY31, 310-314 (1988) Increased Frequency of Complete Hydatidiform Mole in Women with Repeated Abortion1 BARBARA ACAIA, M.D.*, FABIO PARAZZINI, M.D.? "2, CARLO LA VECCHIA, M.D.t, ORIETTA RICCIARDIELLO, M.D.*, LU]GI FEDELE, M.D.*, AND G. BATTISTA CANDIANI, M.D.* *First Obstetrics and Gynecology Clinic of the University of Milan, Via Commenda, 12, 20129 Milan, Italy, and ~Mario Negri Institute for Pharmacological Research, Via Eritrea, 62, 20157 Milan, Italy Received February 26, 1987 The association between spontaneous abortion and gestational trophoblastic disease (GTD) has been investigated in a study based on 93 women with 2 consecutive (repeated) spontaneous abortions and 82 control subjects who delivered normal babies. Nine molar pregnancies were observed among 7 of the 93 cases of repeated abortion while no control reported previous GTD. This difference was statistically significant and was not explained by allowance for age and number of pregnancies between cases and controls (X~ = 4.20; P = 0.04). When the observed number (9) of hydatidiform mole in the 385 pregnancies of the women with repeated abortion was compared with the expected one (0.28) based on the regional frequency data, the estimated relative risk was 32.1 with a 95% confidence interval from 13.9 to 63.3. The present findings confirm the association between GTD and spontaneous abortion and indicate that the risk is larger in women with repeated abortions. © 1988Academic Press, Inc. INTRODUCTION An association between spontaneous abortion and gestational trophoblastic disease (GTD hydatidiform mole and its malignant counterpart, choriocarcinoma) has been recently suggested. Data from studies in the Philippines [1], United States [2,3], and Italy [4,5] have reported a higher proportion of spontaneous abortions in the reproductive history of patients with trophoblastic disease. To reassess the relation between spontaneous abortion and the risk of GTD in the present study we considered the reproductive history of a selected group of women with two or more consecutive spontaneous abortions (repeated abortions) in comparison with a group of women with a comparable number of pregnancies • but no repeated abortion, and to the expected number of cases of trophoblastic disease in the same population. l This study was conducted within the framework of the CNR (Italian National Research Council) applied projects "Preventive and Rehabilitative Medicine" (Contracts 85.00487.56 and 85.00549.56) and Oncology (Contract 85.02209.44). 2 To whom all correspondence should be addressed. 0090-8258/88 $1.50 Copyright© 1988by Academic Press, Inc. All rightsof reproduction in any formreserved. 310