Townsend R R, Laing F C, Nyberg D A, Jeffrey R B, Wing V W
Radiology. 1986 Jul;160(1):105-8. doi: 10.1148/radiology.160.1.3520642.
Whether placental migration occurs is debatable. To determine the incidence of placenta previa in early pregnancy and the frequency of placental migration, a retrospective analysis was undertaken of 2,087 consecutive obstetrical sonograms obtained during a 23-month period. Among 849 patients scanned between 14 and 26 weeks after conception, placenta previa was diagnosed using ultrasonography (US) in 53 patients (6.2%). This diagnosis was confirmed at surgery in 15 patients (1.8%); there were 12 cases of central previa and three cases of partial previa. Retrospective analysis revealed that in 25 cases, technical factors, such as an overly distended urinary bladder (19 cases) or focal uterine contractions (six cases), were responsible for the false-positive diagnoses. In the 13 remaining patients, however, there were no obvious technical difficulties to account for the diagnosis of previa. Migration did not occur in any of the patients with central previa. It appears that placental migration may occur, although less frequently than has previously been reported. Furthermore, this study suggests that migration does not occur in patients with central previa.
胎盘是否会发生迁移仍存在争议。为了确定妊娠早期前置胎盘的发生率以及胎盘迁移的频率，我们对在23个月期间连续获得的2087例产科超声检查进行了回顾性分析。在849例受孕后14至26周接受扫描的患者中，通过超声检查（US）诊断出53例前置胎盘（6.2%）。15例患者（1.8%）在手术中得到证实；其中有12例中央性前置胎盘和3例部分性前置胎盘。回顾性分析显示，在25例中，技术因素，如膀胱过度充盈（19例）或局部子宫收缩（6例），是导致假阳性诊断的原因。然而，在其余13例患者中，没有明显的技术困难来解释前置胎盘的诊断。中央性前置胎盘患者中没有一例发生迁移。似乎胎盘迁移可能会发生，尽管其频率低于先前报道。此外，这项研究表明中央性前置胎盘患者不会发生迁移。
