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

Abstract

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. 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. 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. 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.