A case of complete hydatidiform mole with coexistent fetus: conclusive diagnosis of androgenesis of the molar placenta by variation of paternal acrocentric short arms.

A twin pregnancy consisting of complete hydatidiform mole with coexisting fetus is an extremely rare condition. Recent advances in obstetric ultrasonography and cytogenetic analysis have made the prenatal diagnosis of this rare pregnancy possible. Recent literature advocating DNA polymorphism analysis being required for the accurate diagnosis of complete hydatidiform mole with coexisting fetus is discussed. We present a case of complete hydatidiform mole with coexisting fetus terminated at 16 weeks' gestation. After successful termination of the pregnancy with intravaginal gemeprost, androgenesis of the molar placenta was proven by karyotyping analysis only, without DNA polymorphism analysis, because the short arm of chromosome 21 of the paternal allele had the normal variant satellite. To our knowledge, this is the first case report of complete hydatidiform mole with coexisting fetus diagnosed by variation of the acrocentric short arms, followed by termination with intravaginal gemeprost. We describe the clinical course of our case and review some literature concerning complete hydatidiform mole with coexisting fetus.