Abstract
Amniotic fluid lecithin/sphingomyelin (L/S) ratios were examined in 74 samples from 65 patients with preeclampsia. The median values were comparable to those obtained in a reference series up to 36 weeks of gestation, whereas the median values after 37 weeks of gestation were found to be significantly smaller in the preeclamptic group (p<0.01).
According to the present results a L/S ratio ⩽2 would in fact guarantee no development of respiratory distress syndrome (RDS) in the infants of preeclamptic mothers. On the contrary L/S ratios s ⩽1.6 may be of limited predictive value in these women since only Vy of the children developed RDS. When preeclampsia was combined with intrauterine growth-retardation of the fetus, RDS was found to be less apt to develop.
In 21 samples of amniotic fluid from 13 women with idiopathic intrauterine growth-retardation of the fetus the L/S ratios were significantly below those in the reference series (p<0.05). No case of RDS was observed.