Fetal lung maturity: the adjunctive use of ultrasound

Ultrasonic cephalometry (BPD) was retrospectively studied in 268 patients at risk for the development of hyaline membrane disease (HMD). Thirty-seven patients were diagnosed as having diabetes and were excluded. Of the remaining 231 patients, 123 (53%) were found to have a biparietal diameter of (BPD) greater than or equal to 9.2 cm. There were 92 patients delivered within 5 days of scanning and none developed HMD. A BPD of 9.2 cm corresponded to an L/S ratio of 2.8 (r = 0.45, p less than 0.05). The above results indicate that it is safe to deliver a nondiabetic patient in whom a fetal BPD of 9.2 cm has been obtained.