[Premature birth rate, incidence of cesarean section and perinatal mortality between 1945 and 1980. An analysis of 55,000 births].

56,686 single births between 1945 and 1980 were evaluated in a retrospective study. The results reflect the change which has taken place in obstetrics. Perinatal mortality dropped in a straight line from 48.50/00 to 17.20/00. At the same time, the frequency of Caesarian section increased in non-linear progression from an initial value of 1.9% (1945-1949) to 14.0% (1975-1980). The rate of early births dropped in the first ten years only from 10.6% to 7.3%, followed by an approximately constant value up to 1969. From 1970 onwards, there is a rising tendency (6.7% to 7.7%) which was found in all weight categories. The share of early births in perinatal mortality dropped during the first years only, from 77% to 63%, and has since remained constant. If we compare the periods 1945 to 1959 and 1970 to 1980 with regard to indications for Caesarian section, assuming a birth weight of more than 2500 g, the indication of cessation of labour would rise from the 4th rank to the 1st position, whereas disproportion and asphyxia of the newborn continue to occupy the 2nd and 4th ranks, respectively, despite a relative increase. Meanwhile, the indication "condition after Caesarian section" now occupies the 3rd rank. In newborn weighing less than 2500 g, the prominent indications are early birth, asphyxia, desire to have a child and breech presentation, whereas emergency indications were previously the most important ones.(ABSTRACT TRUNCATED AT 250 WORDS)