Myers J L, Harrell M J, Hill F L
Am J Obstet Gynecol. 1975 Apr 1;121(7):961-7. doi: 10.1016/0002-9378(75)90918-7.
One hundred and three samples of amniotic fluid from 21 normal and 64 medically complicated pregnancies were used for evaluating fetal maturity by measuring one or more of the following: the lecithin-sphingomyelin ratio (L/S), bilirubin concentration, creatinine concentration, and percentage of fetal fat cells. The rapid foam test for surfactant was evaluated in 20 of the samples and found to be unreliable in predicting the risk of respiratory distress syndrome. The test for fat cells gave a large percentage of false negative results, and the creatinine concentration failed to show a good correlation with gestational age. Both the bilirubin concentration and L/S ratio showed good correlation with gestational age. However, since the major cause of death in a premature infant is the respiratory distress syndrome, the maturity of the fetal lung, which is best estimated by the L/S ratio, has to be the prime concern.
从21例正常妊娠和64例有医学并发症的妊娠中获取了103份羊水样本，通过测量以下一项或多项指标来评估胎儿成熟度：卵磷脂 - 鞘磷脂比值（L/S）、胆红素浓度、肌酐浓度和胎儿脂肪细胞百分比。对其中20份样本进行了表面活性物质的快速泡沫试验，发现该试验在预测呼吸窘迫综合征风险方面不可靠。脂肪细胞检测出现了大量假阴性结果，肌酐浓度与孕周未显示出良好的相关性。胆红素浓度和L/S比值均与孕周显示出良好的相关性。然而，由于早产儿的主要死因是呼吸窘迫综合征，通过L/S比值最能准确评估的胎儿肺成熟度必须成为首要关注点。
