[Pregnancy and labor in twins. II. Determination of twin pregnancy and avoidance of premature birth (author's transl)].

In about 65% of the 258 twin births which occurred at the University Gynaecological Hospital, Zürich, from 1966 to 1976, it was possible to diagnose the twin pregnancy before the birth of the first twin. Twin pregnancy could be diagnosed in 96.2% of all the cases before the birth of the first twin, after routine ultrasound diagnosis of pregnancy had been introduced. Prerequisite of optimal treatment of pregnancy is a very early diagnosis which is only possible by widest use of ultrasound investigation technique. The rate of premature births was reduced from 48.0% to 27.3% by means of complete rest in bed and prophylactic tocolysis with a betamimetic from the 32nd to the 37th week of pregnancy. At the same time, the number of underweight children below 2.500 g was reduced by means of this treatment from 60.1% to 34.1%. It seems to be an undisputable fact that prolonged hospitalization in the last three months of pregnancy will improve the prognosis.