Complete Hydatiform Mole with a Coexisting Living Fetus: A Case Report

Background: Gestational trophoblastic diseases comprise the hydatiform moles (HMs), complete or partial, an abnormal development of trophoblastic tissue. HMs derive from a gametogenesis error during conception leading to an anomalous chromosomal asset. In the complete hydatiform mole (CHM), when one or two spermatozoa enter an empty oocyte, the karyotype, paternally derived, is diploid 46,XX or 46,XY. CHM is characterized by massive hydropic degeneration of the villi, with no fetal structures, easily detected by ultrasound (US) in early gestation, confirmed by elevated maternal beta-hCG levels. CHM with coexistent fetus (CHMCF) is an exceptional event with a high risk of malignant progression, and severe complications such as massive vaginal bleeding, preeclampsia, and fetal death. Methods/Results: We present a case of CHMCF in a 29-year-old woman, which resulted in a liveborn and healthy baby at 38 weeks of gestation. The patient was prenatally carefully monitored with biweekly US and periodic beta-hCG levels. Post-partum follow-up consisted of transvaginal US and beta-hCG levels at 1, 3, and 6 months. After 1 year post-delivery, both the mother and the newborn were healthy. Conclusions: CHMCF management can be challenging as shared guidelines are currently lacking and the case described may be helpful in adding more data.