Department of Obstetrics and Gynecology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Japan.
Gynecol Obstet Invest. 2012;73(3):217-22. doi: 10.1159/000333309. Epub 2012 Mar 1.
BACKGROUND/AIMS: To examine the significance of placental migration and the presence of a placental marginal sinus to predict the eventual route of delivery in low-lying placenta.
49 women with a low-lying placenta after 30 weeks' gestation were studied. The distance between the internal os and leading edge of the placenta was measured weekly using transvaginal ultrasonography until 37 weeks' gestation. The relationship between the rate of placental migration, the presence of a placental marginal sinus and the eventual mode of delivery was investigated.
Although the cesarean section rate was 56.3% (9/16) in the 'slow' migration (0-2.0 mm/week) group, no patient (0/33) in the 'fast' (>2.0 mm/week) migration group underwent a cesarean section (p < 0.01). The cesarean section rate was 71.4% (5/7) in patients with a placental marginal sinus, significantly greater than the rate of 9.5% (4/42) in patients without a marginal sinus (p < 0.01).
A decreased rate of placental migration until 37 weeks' gestation and the presence of a placental marginal sinus were associated with subsequent cesarean delivery because of antepartum vaginal bleeding. These parameters may be useful for predicting the route of delivery in women with a low-lying placenta.
背景/目的：探讨胎盘迁移和胎盘边缘窦的存在对预测低置胎盘最终分娩方式的意义。
对 49 例 30 孕周后低置胎盘孕妇进行研究。使用经阴道超声每周测量子宫内口与胎盘前缘之间的距离，直至 37 孕周。研究胎盘迁移率、胎盘边缘窦的存在与最终分娩方式之间的关系。
虽然“慢”迁移（0-2.0mm/周）组剖宫产率为 56.3%（9/16），但“快”迁移（>2.0mm/周）组无一例患者行剖宫产（p<0.01）。有胎盘边缘窦的患者剖宫产率为 71.4%（5/7），显著高于无边缘窦的患者的 9.5%（4/42）（p<0.01）。
直至 37 孕周时胎盘迁移率降低和存在胎盘边缘窦与因产前阴道出血而随后行剖宫产分娩相关。这些参数可能有助于预测低置胎盘孕妇的分娩方式。
