Abstract
Complete hydatidiform mole with a coexisting live fetus (CHMCF) is an exceptionally rare, high-risk obstetric condition, most often seen in dichorionic twin pregnancies, with an estimated incidence of 1 in 20,000-100,000. Maternal complications frequently include vaginal bleeding, early-onset preeclampsia, thyrotoxicosis, and, occasionally, progression to gestational trophoblastic neoplasia (GTN). Fetal outcomes are unpredictable, ranging from spontaneous loss to live birth. We report a case of a 25-year-old gravida 3 para 2 at 24 + 2 weeks' gestation presenting with vaginal bleeding. Ultrasound revealed a viable fetus with a normal placenta and amniotic fluid, alongside a separate multicystic intrauterine mass occupying the internal cervical os, consistent with a complete hydatidiform mole. During hospitalization, she developed worsening bleeding, preeclampsia, thyrotoxicosis, and intrauterine fetal demise. Elective hysterotomy was performed, and pathology confirmed an early third-trimester placenta with a separate complete mole. This case underscores the rapid maternal deterioration possible in CHMCF and highlights the importance of early recognition, intensive monitoring, and multidisciplinary individualized care. A brief review of the literature is included, summarizing maternal and fetal outcomes, diagnostic challenges, and management strategies.