Obstetrics and Gynaecology Department, Graduate Entry Medical School, University of Limerick, Limerick, Ireland.
Biostatistics Department, Graduate Entry Medical School, University of Limerick, Limerick, Ireland.
Syst Rev. 2017 Dec 6;6(1):242. doi: 10.1186/s13643-017-0641-1.
Abnormal placental cord insertion (PCI) includes marginal cord insertion (MCI) and velamentous cord insertion (VCI). VCI has been shown to be associated with adverse pregnancy outcomes. This systematic review and meta-analysis aims to determine the association of abnormal PCI and adverse pregnancy outcomes.
Embase, Medline, CINAHL, Scopus, Web of Science, ClinicalTrials.gov, and Cochrane Databases were searched in December 2016 (from inception to December 2016). The reference lists of eligible studies were scrutinized to identify further studies. Potentially eligible studies were reviewed by two authors independently using the following inclusion criteria: singleton pregnancies, velamentous cord insertion, marginal cord insertion, and pregnancy outcomes. Case reports and series were excluded. The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale. Outcomes for meta-analysis were dichotomous and results are presented as summary risk ratios with 95% confidence intervals.
Seventeen studies were included in the systematic review, all of which were assessed as good quality. Normal PCI and MCI were grouped together as non-VCI and compared with VCI in seven studies. Four studies compared MCI, VCI, and normal PCI separately. Two other studies compared MCI with normal PCI, and VCI was excluded from their analysis. Studies in this systematic review reported an association between abnormal PCI, defined differently across studies, with preterm birth, small for gestational age (SGA), low birthweight (< 2500 g), emergency cesarean delivery, and intrauterine fetal death. Four cohort studies comparing MCI, VCI, and normal PCI separately were included in a meta-analysis resulting in a statistically significant increased risk of emergency cesarean delivery for VCI (pooled RR 2.86, 95% CI 1.56-5.22, P = 0.0006) and abnormal PCI (pooled RR 1.77, 95% CI 1.33-2.36, P < 0.0001) compared to normal PCI.
The available evidence suggests an association between abnormal PCI and emergency cesarean delivery. However, the number of studies with comparable definitions of abnormal PCI was small, limiting the analysis of other adverse pregnancy outcomes, and further research is required.
异常胎盘脐带插入（PCI）包括边缘性脐带插入（MCI）和帆状脐带插入（VCI）。VCI 已被证明与不良妊娠结局有关。本系统评价和荟萃分析旨在确定异常 PCI 与不良妊娠结局之间的关系。
2016 年 12 月（从建库到 2016 年 12 月），我们在 Embase、Medline、CINAHL、Scopus、Web of Science、ClinicalTrials.gov 和 Cochrane 数据库中进行了检索。仔细审查了合格研究的参考文献列表，以确定其他研究。两名作者独立使用以下纳入标准对潜在合格研究进行了审查：单胎妊娠、帆状脐带插入、边缘性脐带插入和妊娠结局。排除病例报告和系列研究。使用纽卡斯尔-渥太华量表评估纳入研究的方法学质量。荟萃分析的结局为二分类，结果以汇总风险比（RR）及其 95%置信区间（CI）表示。
17 项研究被纳入系统评价，所有研究均被评为高质量。7 项研究将正常 PCI 和 MCI 归为非 VCI，并与 VCI 进行比较。4 项研究分别比较了 MCI、VCI 和正常 PCI。另外两项研究比较了 MCI 与正常 PCI，VCI 被排除在他们的分析之外。本系统评价中的研究报告了异常 PCI（不同研究定义不同）与早产、小于胎龄儿（SGA）、低出生体重（<2500g）、急诊剖宫产和宫内胎儿死亡之间的关联。4 项队列研究分别比较了 MCI、VCI 和正常 PCI，其中 3 项被纳入荟萃分析，结果显示 VCI（汇总 RR 2.86，95%CI 1.56-5.22，P=0.0006）和异常 PCI（汇总 RR 1.77，95%CI 1.33-2.36，P<0.0001）与正常 PCI 相比，急诊剖宫产的风险显著增加。
现有证据表明异常 PCI 与急诊剖宫产之间存在关联。然而，具有可比异常 PCI 定义的研究数量较少，限制了对其他不良妊娠结局的分析，需要进一步研究。
Zotero 插件