Thermocoagulation for the Early Treatment of Pregnancy with an Acardiac Twin

In twin pregnancy with acardia, which occurs in about 1 in 35,000 deliveries, the heart and usually other organs fail to develop in one twin.1 The acardiac (“recipient”) twin receives blood from the normal (“pump”) twin, and the blood is then returned to the normal twin.2 The natural history is variable, and some pregnancies proceed to term. Commonly, the acardiac twin becomes grossly edematous, and its size may exceed that of the pump twin. Hydramnios may occur in either sac. The perinatal mortality rate for pump twins is around 55 percent, with death due mainly to congestive cardiac failure or . . .