Tabsh K M
Am J Obstet Gynecol. 1983 Feb 15;145(4):504-8. doi: 10.1016/0002-9378(83)90325-3.
Placental grading with real-time ultrasound was performed on 235 patients who underwent amniocentesis for determination of the lecithin/sphingomyelin (L/S) ratio between 31 and 44 weeks' gestation. Grades I, II, and III placentas were encountered in 88, 72, and 75 patients, respectively. Forty-eight percent of Grade I, 69% of Grade II, and 92% of Grade III placentas had mature L/S ratios (L/S greater than or equal to 2.0). All of the 52 patients with a Grade III placenta who underwent repeat cesarean section at term gestation had mature L/S ratios. However, 37% of the pregnancies complicated by maternal or fetal disease, with Grade III placentas, had immature L/S ratios. The gestational age of these six patients ranged from 34 to 37 weeks. These results suggest that a Grade III placenta in normal term gestation has a good correlation with fetal pulmonary maturity as predicted by the amniotic fluid L/S ratio.
对235例妊娠31至44周接受羊膜穿刺术测定卵磷脂/鞘磷脂（L/S）比值的患者进行了实时超声胎盘分级。分别在88、72和75例患者中发现了I级、II级和III级胎盘。I级胎盘的48%、II级胎盘的69%和III级胎盘的92%具有成熟的L/S比值（L/S大于或等于2.0）。所有52例足月妊娠行再次剖宫产的III级胎盘患者均有成熟的L/S比值。然而，37%患有母亲或胎儿疾病且胎盘为III级的妊娠，其L/S比值不成熟。这6例患者的孕周为34至37周。这些结果表明，足月正常妊娠中的III级胎盘与羊水L/S比值预测的胎儿肺成熟度具有良好的相关性。
