Placenta previa, placenta accreta, and vasa previa
Placenta previa, placenta accreta, and vasa previa
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DOI：
10.1097/01.aog.0000207559.15715.98
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发表时间：
2006-04-01
影响因子：
7.2
通讯作者：
Smulian, John C.
中科院分区：
文献类型：
--
作者：
Oyelese, Yinka;Smulian, John C.
前置胎盘、增生胎盘和前置血管是妊娠后半期和分娩时出血的重要原因。前置胎盘的危险因素包括既往剖宫产、终止妊娠、宫内手术、吸烟、多胎妊娠、胎次增高和产妇年龄。前置胎盘的诊断方法是经阴道超声检查，有完整前置胎盘的妇女应剖腹产。小型研究表明，当胎盘到子宫颈的距离大于2厘米时，女性可以安全地进行阴道分娩。前置胎盘剖宫产的区域麻醉是安全的。分娩应在有充足血库设施的机构进行。增生性胎盘的发病率正在上升，主要是因为剖宫产率的上升。这种情况可能与分娩时大量失血有关。产前影像学诊断，随后规划围产期管理由多学科团队，可能有助于降低发病率和死亡率。已知有胎盘增生的妇女应该剖腹产，在分娩时不应该试图分离胎盘。大多数有明显程度的胎盘增生的妇女将需要子宫切除术。虽然已经有成功的保守治疗的描述，但目前没有足够的数据推荐这种方法作为常规治疗。当胎膜破裂时，前置血管有胎儿失血和死亡的风险。这种情况可以通过产前超声检查来诊断。良好的结局取决于产前诊断和剖宫产膜破裂前。
Placenta previa, placenta accreta, and vasa previa are important causes of bleeding in the second half of pregnancy and in labor. Risk factors for placenta previa include prior cesarean delivery, pregnancy termination, intrauterine surgery, smoking, multifetal gestation, increasing parity, and maternal age. The diagnostic modality of choice for placenta previa is transvaginal ultrasonography, and women with a complete placenta previa should be delivered by cesarean. Small studies suggest that, when the placenta to cervical os distance is greater than 2 cm, women may safely have a vaginal delivery. Regional anesthesia for cesarean delivery in women with placenta previa is safe. Delivery should take place at an institution with adequate blood banking facilities. The incidence of placenta accreta is rising, primarily because of the rise in cesarean delivery rates. This condition can be associated with massive blood loss at delivery. Prenatal diagnosis by imaging, followed by planning of peripartum management by a multidisciplinary team, may help reduce morbidity and mortality. Women known to have placenta accreta should be delivered by cesarean, and no attempt should be made to separate the placenta at the time of delivery. The majority of women with significant degrees of placenta accreta will require a hysterectomy. Although successful conservative management has been described, there are currently insufficient data to recommend this approach to management routinely. Vasa previa carries a risk of fetal exsanguination and death when the membranes rupture. The condition can be diagnosed prenatally by ultrasound examination. Good outcomes depend on prenatal diagnosis and cesarean delivery before the membranes rupture.