Objective: A twin pregnancy consisting of a complete hydatidiform mole with a coexisting normal fetus is extremely rare with an incidence of 1/22,000 to 1/100,000. The incidence of preterm delivery is high and few pregnancies reach near term with a viable fetus. Case report: A 34-year-old woman presented at 20 weeks of gestation with increased levels of serum beta human chorionic gonadotropin (beta-HCG) at 4.74 multiples of the median (310277.7 mIU/mL). Ultrasonography showed a hydatidiform mole together with a normal fetus. Fetal karyotyping revealed 46XY. The serum beta-HCG levels were followed up throughout the remainder of the pregnancy. A male infant weighting 2260 g and the molar tissue were delivered at 37 weeks of gestation. The karyotype of the molar tissue showed 46XX and the histopathological report confirmed our diagnosis. At 4 months postpartum, metastatic gestational trophoblastic disease of the lung was diagnosed in the mother by a computed tomography scan due to increased beta-HCG levels. The patient received three unsuccessful cycles of methotrexate and folinate. Another four cycles of chemotherapy consisting of etoposide, methotrexate, actinomycin D, cyclophosphamide, and vincristine (EMA-CO) were initiated and the beta-HCG levels returned to normal. There was no evidence of recurrence in the subsequent 5 years of regular follow up. Conclusion: A pregnancy with a complete hydatidiform mole and a living cotwin can be a serious threat to the health of both the mother and the fetus. Early diagnosis depends on a combination of detecting an unusually high level of serum beta-HCG and ultrasound examination. We suggest that continuation of the pregnancy may be an acceptable option and that the pregnancy may continue until term if a normal fetal anatomy is assured and maternal complications are under control. Patients require careful postpartum follow up and any recurrent disease should be managed aggressively.
Peng, H. H., Huang, K. G., Chueh, H. Y., Adlan, A. S., Chang, S. D., & Lee, C. L. (2014). Term delivery of a complete hydatidiform mole with a coexisting living fetus followed by successful treatment of maternal metastatic gestational trophoblastic disease. Taiwanese Journal of Obstetrics and Gynecology, 53(3), 397–400. https://doi.org/10.1016/j.tjog.2013.02.005