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

Abstract

Objective: 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).

Patients and methods: 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.

Results: 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.

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