[Significance of amniotic fluid phosphatidylglycerol for the assessment of fetal lung maturity during diabetic pregnancy].

In diabetic pregnancy, a high rate of postnatal development of RDS has been observed even with a mature lecithin/sphingomyelin (L/S) ratio, and the efficacy of phosphatidylglycerol (PG), a second major surfactant phospholipid, in predicting fetal lung maturity remains to be established. In this communication, we determined PG and phosphatidylcholine (PC) in 59 samples of amniotic fluid obtained from 46 pregnant diabetic patients, based on an enzymatic method reported previously. 35 infants who had more than critical PG concentrations (0.36 mumoles/dl) were all associated with normal postnatal respiratory function. 9 out of 10 infants with a PG value lower than this level developed RDS. PG values in patients with mild and severe type diabetes were compared with those of uneventful pregnant women. The appearance of PG was delayed in mild diabetes (Class A, B and C), while it appeared earlier in severe type diabetes (Class D, F and R). Determination of catecholamines together with PG in amniotic fluids of four pregnant women with diabetes indicated that PG values were closely associated with the activities of the fetal adrenergic system. Since an increase in adrenergic activity occurs as a response to fetal distress, amniotic fluid PG is important not only in assessing fetal lung maturity, but also in managing high-risk pregnancies such as diabetic patients.