[The lecithin/spingomyelin quotient as determined using a modified method and human placental lactogen in the amniotic fluid].

Thirty amniotic fluid samples in late gestational age were analysed for HPL-values and the L/S-ratio. The pregnant women used in this study were healthy except three patients who developed a rh-incompatibility. The amniotic fluid was only obtained by abdominal amniocentesis. We found a decreasing tendency of the HPL-values in late pregnancy. The L/S-ratio increased. A significant correlation of both values could not be observed. In all three cases of rh-incompatibility the decrease of HPL and the increase of the L/S-ratio occurred obviously earlier and steeper. Further studies will prove the significance of these results.