Glycosylated hemoglobin as a predictor of fetal pulmonic maturity in insulin-dependent diabetes at term

In insulin dependent diabetic (IDDM) gestations, fetal pulmonary maturity i s delayed in the presence of suboptimal glycemic control. Serum glycosylate d hemoglobin (HbA1c) provides a means of assessing glycemic control. We eva luated maternal HbA1c in IDDM pregnancies at term undergoing amniocentesis for lung maturity to establish if euglycemia is associated with improved fe tal lung maturity. Between July 1995 and lune 1996, IDDM patients undergoin g amniocentesis at term for lung maturity studies had a maternal serum samp le analyzed for HbA1c. Fetal lung maturity was established by the presence of phosphatidylglycerol (PG) in amniotic fluid. HbA1c was considered elevat ed if >6.2%. Mean HbA1c level was 6.8% (range 4.4 to 9.9%). PC was present in 54% of patients with elevated HbA1c (7/13) versus 80% of those with norm al HbA1c (8/10) (p = 0.4). Although birth weight was higher in the elevated than in the normal HbA1c group (3770 +/- 514 vs. 3215 +/- 610 g), no assoc iation was present between birth weight and HbA1c level (r = 0.22, p = 0.4) . The rate of a mature pulmonic profile at term is not significantly differ ent between IDDM women with good or poor glycemic control. HbA1c values sho uld not be used to predict the presence or absence of amniotic fluid PG.