[Twin pregnancy, one fetus with Down syndrome removed by sectio parva, the other delivered mature and healthy (author's transl)].

We report about a twin pregnancy with trisomy 21 in one of the fetus and normal caryotype of the other one. The affected fetus was removed by sectio parva in the 22nd week of gestation (p. m.) while the placenta remained inside the uterus. At the end of the 38th week of gestation a mature healthy baby was delivered by caesarean section. This was only possible by knowing the exact position of the fetus, placentas and amnion cavities by ultrasound. It is necessary to be familiar with betamimetics for tocolysis used during and after surgery.