Twin pregnancy with complete hydatidiform mole and coexistent fetus: Obstetrical and oncological outcomes in a series of 14 cases

Abstract

Objective Twin pregnancy with complete hydatidiform mole and coexistent fetus (CHM&CF) is a rare situation and a challenge for diagnosis. Results related to fetal outcome and maternal risk of subsequent gestational trophoblastic neoplasia (GTN) are controversial. We here display a series from the French Trophoblastic Disease Reference Center, which is to date the third in number of cases registered by the same center. Study design By retrospective method based on patients from the French Trophoblastic Disease Reference Center data base between November 1999 and December 2006, 17 assumed cases were reviewed. In 14 cases the diagnosis of CHM&CF was ascertained. All files were reviewed to confirm diagnosis. Methods of initial diagnosis, outcome of pregnancy and evolution to GTN were studied. Results In 10 cases (71%) diagnosis was made by ultrasonography. Differential diagnoses were partial hydatidiform mole and mesenchymal dysplasia. Three patients in 14 (21%) delivered a healthy child. In only one case, delivery occurred after 37 weeks of gestation. Seven patients (50%) had a diagnosis of GTN. No patient had fatal evolution. Clinical events, such as vaginal bleeding, pre-eclampsia or hyperthyroidism, had no effect on the evolution to GTN. Continuation of the pregnancy did not increase the risk of GTN. Conclusion In case of prenatal diagnosis of CHM&CF, and even if delivery of a healthy child is possible, patients should be aware of a possibly higher risk of GTN than in CHM.