Hasegawa Junichi, Higashi Miwa, Takahashi Shoko, Mimura Takashi, Nakamura Masamitsu, Matsuoka Ryu, Ichizuka Kiyotake, Sekizawa Akihiko, Okai Takashi
Department of Obstetrics and Gynecology, Showa University School of Medicine, Tokyo, Japan.
J Clin Ultrasound. 2011 Oct;39(8):458-62. doi: 10.1002/jcu.20849. Epub 2011 Jun 10.
To evaluate the abnormal sonographic (US) findings in patients with placenta previa and bleeding.
A total of 182 cases of singleton pregnancies with placenta previa were reviewed. The US findings including the type of placenta previa, placental location, presence of placenta lacunae, lack of clear zone, sinus venosus at the margin of the placenta, velamentous cord insertion, sponge-like echo in the cervix and cervical length were evaluated in relation to episodes of bleeding that required in-patient treatment during pregnancy and/or emergency cesarean section.
Episodes of antenatal bleeding occurred in 102/182 (56%) patients with placenta previa. An emergency cesarean section was performed in 66 (64.7%) of these 102 patients. In the 80 patients without episodes of antenatal bleeding, an emergency cesarean section was performed in only 1 (1.3%). Detection of US findings just prior to cesarean section was not associated with the need for emergency cesarean section due to uncontrollable bleeding from the placenta previa. Frequencies of each US finding at 20 weeks of gestation were not different between the patients who underwent emergency cesarean sections and the others. Frequency of marginal sinus was slightly higher in cases with bleeding episode (16% versus 0%, p < 0.05), but the other US findings were not associated with the occurrence of bleeding episodes during pregnancy.
No US finding could predict bleeding episodes and the eventual need for an emergency cesarean section. The obstetrician should be aware that sudden bleeding during pregnancy may occur in patients with placenta previa, even in the absence of any other US findings.
评估前置胎盘并出血患者的超声异常表现。
回顾性分析182例单胎妊娠前置胎盘患者。评估超声表现，包括前置胎盘类型、胎盘位置、胎盘腔隙的存在、无清晰区、胎盘边缘的静脉窦、帆状脐带附着、宫颈海绵样回声及宫颈长度，并与孕期需住院治疗的出血事件和/或急诊剖宫产相关联。
182例前置胎盘患者中，102例（56%）发生产前出血。这102例患者中有66例（64.7%）接受了急诊剖宫产。在80例无产前出血的患者中，仅1例（1.3%）接受了急诊剖宫产。剖宫产术前超声表现与因前置胎盘不可控出血而需急诊剖宫产无关。急诊剖宫产患者与其他患者在妊娠20周时各超声表现的频率无差异。有出血事件的病例中边缘静脉窦的频率略高（16%对0%，p<0.05），但其他超声表现与孕期出血事件的发生无关。
没有超声表现能够预测出血事件及最终是否需要急诊剖宫产。产科医生应意识到，前置胎盘患者即使没有任何其他超声表现，孕期也可能突然发生出血。
