Fetal lung maturity in pregnancies complicated by insulin-dependent and gestational diabetes: a matched cohort study

To study fetal lung maturity (FLM) as determined by amniotic fluid (AF) tests in diabetic pregnancies (DP) under euglycemic metabolic control, in comparison with matched controls (C).

From 514 consecutive pregnancies where amniocentesis was performed for FLM assessment, we selected 45 glycemic controlled DP. Nineteen DP were Type I (IDDM) and 26 pregnancies were diagnosed Type III (GDM). Cases were matched to C by therapy with corticosteroids, gestational age at amniocentesis, pregnancy complications other than diabetes and gender. FLM was determined by the shake test and lamellar bodies (LB) count, lecithin/sphingomyelin (L/S) ratio (planimetric and stechiometric) and phosphatidylglycerol presence (PG). DP were further sub-divided according to gestational age period at amniocentesis, type of diabetes, associated therapy and fetal malformations.

RDS (n=2) and neonatal wet lung (n=5) were diagnosed in neonates from diabetic mothers. We found no statistical difference when comparing FLM indices between DP and C groups: shake test 3.1:1+/-1.2 vs. 2.7:1+/-1.2, P<0.40; planimetric L/S 3.4+/-1.4 vs. 3.1+/-2.0, P<0.27; stechiometric L/S 8.2+/-7.4 vs. 7.1+/-6.1, P<0.54; percentage of PG positivity 57% vs. 46%, P<0.13; lamellar bodies count (X10(3)/microl) 42.8+/-36.9 vs. 41.5+/-30.4, P<0.72. No differences were found between DP and controls for subgroups according to gestational age, type of Diabetes (IDDM or GDM), congenital lesions and associated therapy.

In euglycemic, metabolically controlled diabetic patients FLM is not delayed, however an increased risk for neonatal wet lung should be considered.