Twin pregnancy consisting of a complete hydatidiform mole and co-existent fetus: report of two cases and review of literature.

Hydatidiform mole with co-existing live fetus is a rare entity. Two cases are reported. In the first, complete mole with a co-existing live fetus was suspected on ultrasound examination at 16 weeks of gestation. A termination of pregnancy was performed due to early onset of severe preeclampsia and thyrotoxicosis. In the second case, the patient was admitted at 26 weeks of gestation due to preeclampsia. Genetic amniocentesis at 19 weeks of gestation revealed a normal 46 XX karyotype. Ultrasound examination at 21 weeks of gestation demonstrated two cystic lesions in the fetal liver, wide multicystic placenta and polyhydramnious. Following deteriorating severe preeclampsia, a live female infant (730 g) along with a huge placenta (1350 g) was delivered by a cesarean section. Unfortunately, the newborn died after 35 days. Pathological examination in both cases was consistent with a complete mole co-existing with a viable fetus. During a 1 year follow up period, there was no evidence of persistent or metastatic disease in both cases. Review of literature discussing the diagnostic tools, clinical features, management and outcome of pregnancies with complete mole with a co-existing live fetus is presented.