[Predictive value of fetal pulmonary maturity tests in pregnancy of diabetic mothers].

Respiratory distress syndrome is a common morbidity in a infants of diabetic mother however there is a controversy in the literature about apparition of lung maturity in this infants. However this reports have not got a control group. Lung maturity tests were prospectively studied, obtained by amniocentesis at 37 weeks of gestation, in 47 patients: twenty diabetics (studied group) and 27 healthy pregnant women (control group). All the pregnancies were solved by cesarean section. The values of lung maturity tests were related to presence of respiratory morbidity in neonates (respiratory distress syndrome: RDS). Five of 49 infants had some kind of respiratory morbidity. The incidence of RDS was 10.2%. Four of 5 infants with RDS belonged to the diabetic group, which gives us an incidence of 20% versus only one of the 29 healthy infants (3.7%). This difference is statistically significant, p < 0.0001. Four infants had false positive lung maturity tests (Od, L/S), three of them (two with severe metabolic meladjustment) occurred in the study group, with alteration of L/S ratio (3/20 = 15%). There was no false positive in PG (specificity 100%) in both group. The 3 lung maturity tests had a specificity of a hundred per cent in the control group). This study shows that the presence of PG in amniotic fluid of diabetic pregnant women confirms maturity with a very low risk to develop RDS. Finally, when the metabolic control of the diabetic is not appropriate, the L/S ratio may give false positive results in 15% of cases, which is quite important.