Trisomy 21 fetus co-existent with a partial molar pregnancy: case report.

Background: Approximately 1 in 1,000 pregnancies in the United States are complicated by the presence of a hydatidiform mole. A Medline search revealed no reported cases of a trisomic fetus co-existent from 1966-1998. We present the case of a patient, initially found to have hypertension, edema, and proteinuria in the first trimester, and later found to have a partial molar gestation co-existent with a trisomy 21 infant.

Case Report: A 31-year-old female presented to her family practitioner in the first trimester and was found to have hypertension and proteinuria. A thorough work-up by a nephrologist revealed no cause. The patient was transferred to the Maternal-Fetal Medicine Service at 26 weeks' and 1 day estimated gestational age. An amniocentesis revealed the presence of a fetus with trisomy 21. At 27 weeks' and 3 days estimated gestational age, the patient underwent a cesarean delivery for a non-reassuring fetal heart rate. Pathologic examination of the placenta revealed the presence of a partial hydatidiform molar pregnancy.

Conclusion: The present account represents the first reported case of a fetus with trisomy 21 co-existent with a partial hydatidiform mole.