[Selective termination of the development of the defective fetus in discordant twin pregnancies].

Selective termination of the affected fetus in twin pregnancies was performed in the second trimester of seven pregnancies. The malformations included anencephaly/exencephaly (2 cases), hydrocephalus (1 case), thoracoabdominopagus of "B" and "C" cotwins (1 case), urethral obstruction sequence (1 case) and hygroma colli (2 cases). Intrauterine intervention on the affected fetus was done by transabdominal intracardial injection of 20% NaCl solution in the 15--24 weeks of gestation. All cases had dichorionic placentation. Unaffected co-twin infants were delivered at term with normal weight in 4 cases. In 2 cases the affected fetus was found in the lower gestational sac and both pregnancies, as well as the triplet pregnancy were lost 1--6 weeks and 3 weeks after the intervention, respectively. In the other cases, neither the mother, nor the survived fetus showed any complications. We believe that using hypertonic saline is lethal for the affected fetus but carries little or no risk either the other fetus or the mother, even if small amounts of the solution might inadvertently enter their circulation.