Division of Maternal and Fetal Medicine, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada; Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada.
Division of Maternal and Fetal Medicine, Department of Obstetrics and Gynaecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada; University of Utah School of Medicine, Salt Lake City, UT.
Am J Obstet Gynecol MFM. 2020 Aug;2(3):100117. doi: 10.1016/j.ajogmf.2020.100117. Epub 2020 Apr 15.
To systematically review published literature and calculate the prevalence of vasa previa and its known risk factors.
MEDLINE, Embase, the Cochrane Library, PubMed (non-MEDLINE and in process), and www.clinicaltrials.gov were searched from inception to March 2018 using indexing terms "vasa previa," "placenta previa," "low lying placenta," "succenturiate lobe," "bilobate placenta," "bilobed placenta," and "velamentous insertion." All original research studies reporting on 5 or more pregnancies with vasa previa were included. The search was limited to studies on human data and those published in the English language. Two reviewers independently screened titles and abstracts, completed data extraction, and assessed reporting quality using the Study Quality Assessment Tool for Case Series Studies of the National Heart, Lung, and Blood Institute. Disagreements were discussed and resolved at each step of the process.
We included 21 studies that reported 428 pregnancies with vasa previa of 1,027,918 deliveries (0.46 cases of vasa previa per 1000 deliveries). These studies fared well on risk of bias assessment using the Study Quality Assessment Tool for Case Series Studies of the National Heart, Lung, and Blood Institute. The prevalence and 95% confidence intervals of known risk factors for vasa previa included a low-lying placenta (61.5%, 53.0%-70.0%), velamentous cord insertion (52.2%, 39.6%-64.7%), bilobed or succenturiate lobed placenta (33.3%, 20.9%-45.7%), use of in vitro fertilization (26.4%, 16.0%-36.8%), and multiple gestation (8.92%, 5.33%-12.5%).
Vasa previa affects 0.46 cases per 1000 pregnancies. Given the high prevalence of prenatally detectable risk factors in affected pregnancies, the cost-effectiveness of screening strategies for vasa previa either in isolation, using a risk factor-based approach, or universally, in tandem with cervical-length screening using transvaginal ultrasound, should be revisited.
系统回顾已发表的文献，计算帆状胎盘前置及其已知危险因素的发生率。
从建库到 2018 年 3 月，使用索引词“vasa previa”、“placenta previa”、“low lying placenta”、“succenturiate lobe”、“bilobate placenta”、“bilobed placenta”和“velamentous insertion”，检索 MEDLINE、Embase、Cochrane 图书馆、PubMed（非 MEDLINE 和进行中）和 www.clinicaltrials.gov，纳入报道 5 例或 5 例以上帆状胎盘前置孕妇的原始研究。仅纳入研究人群为人类数据且以英文发表的研究。两位评审员独立筛选标题和摘要、完成数据提取，并使用国立心肺血液研究所病例系列研究质量评估工具评估报告质量。意见分歧在研究过程的每个步骤都进行了讨论和解决。
我们纳入 21 项研究，共计 428 例帆状胎盘前置孕妇，共涉及 1027918 例分娩（每 1000 例分娩中有 0.46 例帆状胎盘前置）。这些研究使用国立心肺血液研究所病例系列研究质量评估工具进行偏倚风险评估，结果良好。帆状胎盘前置的已知危险因素的发生率及其 95%置信区间包括胎盘位置低（61.5%，53.0%-70.0%）、脐带帆状附着（52.2%，39.6%-64.7%）、双叶或球拍状胎盘（33.3%，20.9%-45.7%）、体外受精（26.4%，16.0%-36.8%）和多胎妊娠（8.92%，5.33%-12.5%）。
每 1000 例妊娠中会出现 0.46 例帆状胎盘前置。鉴于在有症状的妊娠中，有很多可在产前检测到的危险因素，因此应该重新评估孤立筛查、基于危险因素筛查、还是普遍筛查（与经阴道超声测量宫颈长度联合）帆状胎盘前置的成本效益，特别是考虑到其高发生率。
