[Feto-maternal microtranfusion after amniocentesis in the 2nd trimenon (author's transl)].

120 healthy patients 16 to 34 years of age were studied. All patients were admitted to the clinic for legal abortion and were admitted to the clinic for legal abortion and were between 16 and 20 weeks pregnant. Amniocentesis were performed for intraamniotic application of prostaglandins. The incidence of microtransfusion of fetal red blood cells in these patients were studied. Blood samples were taken before and one hour after amniocentesis. 104 patients (86.7 p.c.) did not show any fetal erythrocytes in the peripheral blood neither before nore after amniocentesis. In ten patients (8.4 p.c.) less than 0.055 ml transfused fetal blood were determined as well before as after the puncture of the amniotic sac without any increasing tendency. In six patients (4.9 p.c.) signs of an induced fetal-maternal-microtransfusion could be proved. All six patients had no fetal cells in the circulation before treatment. Four of these had a microtransfusion of less than 0.05 ml, two patients between 0.05 and 0.10 ml. The localisation of the placenta by ultrasonic technic as an absolutely demand before amniocentesis is strongly recommended, especially in cases of prenatal diagnostic purpose.