Twin pregnancy and partial hydatidiform mole following in vitro fertilization and embryos transfer: a novel case of placental mosaicism.

Twin pregnancy with mosaic partial hydatidiform mole (PHM) and survival of two healthy fetuses following in vitro fertilization and embryos transfer (IVF-ET) is a rare situation and is considered a challenge for management. A 32-year-old Chinese woman conceived twin pregnancy following IVF-ET. At 22 weeks' gestation, an additional intrauterine echogenic mass with features of PHM were shown by successive ultrasound examinations. At 35 weeks' gestation, two live male infants and two placentas were delivered by caesarean section (CS). Histologic examination of the abnormal placenta confirmed mosaic PHM. Genetic study showed the abnormal placental mosaicism (expressed in molar-69XXY and normal vili-46XY), co-existing with a hypospadia new-born (46XY) in one amniotic sac. However, the other one was normal. Serial serum β-hCG levels showed a declining trend and serum β-human chorionic gonadotropin (hCG) were undetectable at 6 months after delivery. The case demonstrated that it is possible to prolonged gestation by PHM under close surveillance during the entire pregnancy.