Twin pregnancy with a partial hydatidiform mole and a coexistent live fetus. Diagnostic and therapeutic dilemmas. A case report and the review of literature

Objectives: We report the case of a twin pregnancy with a partial hydatidiform mole and a coexistent live fetus diagnosed in a 28-year-old primipara at 15 weeks of gestation and discuss the problems associated with the ultrasound diagnosis, histopathological examination of molar tissue samples and treatment. Material and methods: A systematic research of the literature was conducted in PubMed database and Cochrane Library, including case reports and case series. A new case was also discussed. We collected data regarding the patient's serum human chorionic gonadotropin (hCG) level, initial symptoms, diagnosis and treatment. Results: Most of the cases reported in the literature are those of a multiple pregnancy with complete hydatidiform mole (CHM) and a coexistent live fetus. The coexistence of a twin pregnancy with partial hydatidiform mole (PHM) and a live fetus in two separate amniotic sacs is extremely rare as a partial mole usually causes miscarriage of early pregnancy. Ultrasound is an important diagnostic tool, but the correct diagnosis is made only in 68% of cases. With further histological assessment of molar specimens and biochemical assays, the rates of correct early diagnoses should increase contributing to early therapeutic decisions and fewer adverse events. Conclusions: The diagnosis, management, and monitoring of this condition will remain challenging because of its rarity. Because of that, all cases of a suspected multiple pregnancy with a hydatidiform mole and a coexistent live fetus should be referred to and managed at a tertiary center which specializes in the diagnosis and treatment of gestational trophoblastic disease.