[The antepartum evaluation of pulmonary maturity in high risk pregnancies (author's transl)].

In normal pregnancies the determination of the L/S ratio permits a reliable ante-partum evaluation of fetal maturity. Good correlation between ante-partum determination and the condition of the newborn is obtained. In the 566 L/S ratios obtained from abnormal pregnancies the method was also reliable. There was 217 Rh incompatabilities, 51 pre-eclampsias, 31 diabetic patients, 112 premature labours, 78 placental insufficiencies and 77 premature ruptures of the membranes. In patients with diabetes the ante-partum diagnosis of pulmonary maturity is doubtful. In some patients with diabetes pulmonary maturity appears to be delayed. A difference between the abnormal pregnancies was not recognized. In the different types of high risk pregnancies no acceleration or retardation of pulmonary maturity was detected with statistical significance. However, in some cases of premature rupture of the membranes, premature labour and placental insufficiency, pulmonary maturity appears to be accelerated.