Selective termination for fetal anomaly/genetic disorder in twin pregnancy at 32+ menstrual weeks. Report of four cases.

Objectives: To conduct a pilot study of 4 cases of selective termination of a single abnormal fetus in a dichorionic, diamniotic twin pregnancy advanced to 32 or more menstrual weeks of gestation.

Study Design: This is a case series of 4 patients in highly unusual circumstances and treatment. Four healthy patients with desired pregnancies complicated by the presence of an abnormal genetic or developmental diagnosis in 1 twin were treated by selective termination of the abnormal twin using intracardiac injection of potassium chloride.

Results: In all 4 patients, cardiac arrest in the abnormal twin was effected without disturbance of the healthy twin or the mother. Postoperative maternal serum potassium levels remained at normal levels. Delivery of a healthy surviving twin occurred from 2 days to 4 weeks following the selective termination along with delivery of a stillborn abnormal twin.

Conclusion: Selective termination of an abnormal twin may be performed on an outpatient basis in the last weeks of pregnancy.