A twin pregnancy with partial hydatidiform mole and a coexisting normal fetus delivered at term: A case report and literature review

Hydatiform mole occurs in 1/1000 singleton and 1/20000–100,000 twin pregnancies. Although the pregnancy often ends in a miscarriage or presents with many obstetric complications such as preeclampsia, vaginal bleeding, hyperthyroidism, prematurity, or fetal malformations, in some cases of twin pregnancy, one of the fetuses can develop normally. Coexistence of a viable fetus in a twin molar pregnancy is more commonly described for cases of complete hydatiform moles than partial hydatiform moles. A partial hydatiform mole coexisting with a normal fetus was suspected in a 40-year-old woman, G2P1, at twelve weeks of gestation of a twin dichorionic diamniotic pregnancy. Serial antenatal ultrasound scans and serial evaluations of human chorionic gonadotropin were performed, and a healthy baby was delivered at term without any obstetric or neonatal complications. A twin pregnancy with partial hydatidiform mole and a coexisting normal fetus is a rare obstetric condition that can result, under proper management, in the delivery of a healthy baby without any sequelae for the mother or child.