[The lecithin-sphynogomyelin ratio in the amniotic fluid in insulin dependent diabetic pregnancies]

A delay in the pulmonary maturation of the foetus of diabetic mothers assessed by the lecithin-sphingomyelin (L/S) ratio has been reported (2, 3, 5). A suggestion has been raised that the results of the L/S ratio should be viewed with caution in predicting lung maturity in pregnancies complicated by maternal diabetes (8). We report our findings on 52 insulin-dependent diabetic pregnancies which involved 90 estimations of the L/S ratio on the amniotic fluid. In all cases, the L/S ratio accurately reflected lung maturity, as no hyaline membrane disease (HMD) was observed with a L/S ratio greater than 2. There was no significant difference in the proportion of mature fetal lung between insulin-dependent diabetics and controls for each week of pregnancy between 32 and 38 weeks. There is no statistical difference in the mature L/S ratio between classes B + C and D + F diabetics.