Department of Obstetrics and Gynecology, McGill University, Montreal, Canada.
Faculty of Medicine, McGill University, Montreal, Quebec, Canada.
J Perinat Med. 2019 Aug 27;47(6):577-584. doi: 10.1515/jpm-2019-0116.
Background Whether placental location confers specific neonatal risks is controversial. In particular, whether placenta previa is associated with intra-uterine growth restriction (IUGR)/small for gestational age (SGA) remains a matter of debate. Methods We searched Medline, EMBASE, Google Scholar, Scopus, ISI Web of Science and Cochrane database search, as well as PubMed (www.pubmed.gov) until the end of December 2018 to conduct a systematic review and meta-analysis to determine the risk of IUGR/SGA in cases of placenta previa. We defined IUGR/SGA as birth weight below the 10th percentile, regardless of the terminology used in individual studies. Risk of bias was assessed using the Cochrane Handbook for Systematic Reviews of Interventions. We used odds ratios (OR) and a fixed effects (FE) model to calculate weighted estimates in a forest plot. Statistical homogeneity was checked with the I2 statistic using Review Manager 5.3.5 (The Cochrane Collaboration, 2014). Results We obtained 357 records, of which 13 met the inclusion criteria. All study designs were retrospective in nature, and included 11 cohort and two case-control studies. A total of 1,593,226 singleton pregnancies were included, of which 10,575 had a placenta previa. The incidence of growth abnormalities was 8.7/100 births in cases of placenta previa vs. 5.8/100 births among controls. Relative to cases with alternative placental location, pregnancies with placenta previa were associated with a mild increase in the risk of IUGR/SGA, with a pooled OR [95% confidence interval (CI)] of 1.19 (1.10-1.27). Statistical heterogeneity was high with an I2 = 94%. Conclusion Neonates from pregnancies with placenta previa have a mild increase in the risk of IUGR/SGA.
胎盘位置是否会带来特定的新生儿风险存在争议。特别是，前置胎盘是否与宫内生长受限（IUGR）/小于胎龄儿（SGA）有关，仍然存在争议。
我们检索了 Medline、EMBASE、Google Scholar、Scopus、ISI Web of Science 和 Cochrane 数据库搜索，以及 PubMed（www.pubmed.gov），截至 2018 年 12 月底，进行了系统评价和荟萃分析，以确定前置胎盘病例中 IUGR/SGA 的风险。我们将 IUGR/SGA 定义为出生体重低于第 10 百分位数，无论个别研究中使用的术语如何。使用 Cochrane 干预系统评价手册评估偏倚风险。我们使用比值比（OR）和固定效应（FE）模型在森林图中计算加权估计值。使用 Review Manager 5.3.5（Cochrane 协作，2014 年）中的 I2 统计量检查统计同质性。
我们获得了 357 条记录，其中 13 条符合纳入标准。所有研究设计均为回顾性，包括 11 项队列研究和 2 项病例对照研究。共纳入 1593226 例单胎妊娠，其中 10575 例胎盘前置。胎盘前置病例的生长异常发生率为每 100 例出生 8.7 例，对照组为每 100 例出生 5.8 例。与胎盘位置异常的病例相比，胎盘前置的妊娠与 IUGR/SGA 的风险轻度增加相关，合并 OR [95%置信区间（CI）]为 1.19（1.10-1.27）。异质性高，I2=94%。
胎盘前置的妊娠新生儿发生 IUGR/SGA 的风险略有增加。
