Use of the TDx-FLM assay in evaluating fetal lung maturity in an insulin-dependent diabetic population

Objective To assess the usefulness of the recently introduced TDx-FLM assay in managing pregnant women with diabetes. Methods Participating institutions were recruited from the 1993 and 1994 Society of Perinatal Obstetricians Diabetes Special Interest Group meetings. Study patients consisted of insulin-dependent diabetic women who had undergone transabdominal amniocentesis with assay of the fluid by the TDx-FLM method. Pertinent data were requested concerning pregnancy and respiratory outcomes of the corresponding neonates. Results Data from 261 pregnancies at 13 institutions were collected. Eight of the 182 infants born within 4 days of amniocentesis developed respiratory distress syndrome (RDS); five of the eight infants with RDS required intubation, and all five had TDx-FLM values less than 70 mg of surfactant per gram of albumin. Three of the eight infants with RDS required hood oxygen only; two of these infants had TDx-FLM values at least 70 mg/g. Thirteen of 144 (9%) subjects who delivered within 4 days of amniocentesis and for whom a TDx-FLM assay and phosphatidylglycerol level were both reported had a TDx-FLM level of at least 70 mg/g and a negative phosphatidylglycerol result. No infant with this combination of results developed RDS. Fifteen of the 40 patients who delivered more than 4 days after amniocentesis, with both tests available, had TDx-FLM values at least 70 mg/g and were phosphatidylglycerol negative. Conclusion In infants of diabetic mothers, TDx-FLM values at least 70 mg/g were not associated with RDS requiring intubation. The TDx-FLM assay may be useful in determining the best time of delivery for pregnant patients with diabetes, especially in a situation in which the TDx-FLM assay is mature and the phosphatidylglycerol result is immature.