Dichorionic multiple gestations
Selective termination can be easily carried out in dichorionic gestations by the transabdominal percutaneous procedure.39 Under ultrasound guidance, the intracardiac injection of KCl is given to the targeted fetus using a 20 or 22-gauge needle until asystole is confirmed.
Evans40 published the largest multicenter series on outcomes of ST in dizygotic pregnancies for structural or chromosomal anomalies. They reported loss rates with gestation of procedure with rates of 5.4% at 9-12 weeks, 8.7% at 13-18 weeks and 9.1% at >25 weeks, although these did not reach significance. The mean gestation at delivery was 35.7 weeks with a liveborn infant in >90% of cases. They concluded ST, in the most experienced hands, can be technically performed in all 3 trimesters (if legal) with good outcomes in >90% of cases.
This report was followed by several single-center series41-43 which confirmed ST in DC pregnancy with discordant anomaly to be a safe, feasible and effective option. With experience, the procedure-loss rate is reported as 4% and mean gestational age at delivery as 38 weeks.