Background: Triploid molar pregnancies are usually managed by evacuation of the uterine contents.
Case: A 25-year-old woman had a clomiphene citrate-induced twin pregnancy. Ultrasound scan at 13 weeks revealed one anomalous twin. Cytogenetic analysis revealed a karyotype of 69, XXY and a normal other twin. In an attempt to salvage the normal fetus, selective termination was successfully performed at 15 weeks by intracardiac potassium chloride injection. However, the placenta continued to grow and severe preeclampsia developed at 19 weeks, requiring pregnancy termination.
Conclusion: Selective termination of a triploid twin does not guarantee resolution of molar growth and sequelae of the mole; severe preeclampsia can still develop.