Winter R
Geburtshilfe Frauenheilkd. 1978 Dec;38(12):1093-8.
Starting from the tenth to the sixteenth week of pregnancy ultrasonic placental localizations were performed in 22 pregnant women at four week intervals. In all cases the placenta was located in the anterior wall of the uterus and bordered or covered the internal os of the cervix. In 17 cases a cephalad migration of the placental localization was registered. In 5 cases the low implantation of the placenta did not change until delivery. In 14 of 19 cases marginal atrophic changes of the placenta were found. No morphologic abnormality was detected in five placentas from patients who showed migration of the placental localization. Since the placenta is tightly implanted in the endometrium a true migration of the placenta is unlikely. Our investigations show that areas of low implantation of the placenta are stretched with increasing growth of the uterus and then undergo regressive and pressure atrophy changes. It is likely that the cervical margin of the placenta cannot be detected by ultrasound in a large number of cases.
从妊娠第10周到第16周，对22名孕妇每隔4周进行一次超声胎盘定位。所有病例中，胎盘均位于子宫前壁，与宫颈内口相邻或覆盖宫颈内口。17例记录到胎盘定位向头侧迁移。5例胎盘低置状态直至分娩未改变。19例中有14例发现胎盘边缘萎缩性改变。在胎盘定位有迁移的患者的5个胎盘中未检测到形态学异常。由于胎盘紧密植入子宫内膜，胎盘真正迁移不太可能。我们的研究表明，胎盘低置区域随着子宫增大而被拉伸，随后发生退行性和压迫性萎缩改变。很可能在大量病例中超声无法检测到胎盘的宫颈边缘。
