OBJECTIVE: 

To compare outcomes of women with low-lying placenta by planned mode of delivery and distance from the internal os distance.

METHODS: 

Six tertiary maternity hospitals in France participated in this retrospective multicenter study of births from 2007–2012. Women with low-lying placenta, defined as an internal os distance of 20 mm or less, who gave birth after 35 weeks of gestation were included and classified in the planned trial-of-labor or elective cesarean delivery groups. The primary endpoint was severe postpartum hemorrhage (PPH) defined as blood loss exceeding 1,000 mL. Secondary outcomes were composite variables of severe maternal and neonatal morbidity. We used multivariable logistic regression and propensity scores to compare outcomes by planned mode of delivery.

RESULTS: 

Among 128,233 births during the study period, 171 (0.13%) women had low-lying placenta: 70 (40.9%) in the trial-of-labor group and 101 (59.1%) who underwent elective cesarean delivery. The rate of severe PPH was 22.9% (16/70, 95% CI 13.7–34.4) for the trial-of-labor group and 23.0% (23/101, 95% CI 15.2–32.5) for the cesarean delivery group (P=.9); severe maternal and neonatal morbidity rates were likewise similar (2.9% vs 2.0% [P=.7] and 12.9% vs 9.9% [P=.5], respectively). Trial-of-labor was not significantly associated with a higher rate of severe PPH after multivariable logistic regression and propensity score-weighted analysis (adjusted odds ratio [aOR] 1.42, 95% CI 0.62–3.24 [P=.4]; and aOR 1.34, 95% CI 0.53–3.38 [P=.5], respectively). The vaginal delivery rate in the trial-of-labor group was 50.0% (19/38) in those with an internal os distance of 11–20 mm and 18.5% (5/27) in those with a distance of 1–10 mm.

CONCLUSION: 

Our results support a policy of offering a trial of labor to women with low-lying placenta after 35 weeks of gestation and an internal os distance of 11–20 mm. An internal os distance of 1–10 mm reduces the likelihood of vaginal birth considerably, compared with 11–20 mm, but without increasing the incidence of severe PPH or severe maternal morbidity.

中文翻译：

---

低位胎盘分娩与择期剖宫产的比较试验

客观的： 

通过计划分娩方式和距内口距离比较低置胎盘女性的结局。

方法： 

法国的六家三级妇产医院参与了这项关于 2007-2012 年出生的回顾性多中心研究。低位胎盘（定义为内口距离为 20 毫米或更小）在妊娠 35 周后分娩的妇女被纳入计划试产或择期剖宫产分娩组。主要终点是严重的产后出血（PPH），定义为失血量超过 1,000 毫升。次要结果是严重孕产妇和新生儿发病率的复合变量。我们使用多变量逻辑回归和倾向评分来比较计划分娩方式的结果。

结果： 

在研究期间的 128,233 例分娩中，171 例 (0.13%) 妇女有低位胎盘：试产组 70 例 (40.9%) 和择期剖宫产的 101 例 (59.1%)。试产组的严重 PPH 发生率为 22.9%（16/70，95% CI 13.7–34.4），剖宫产组为 23.0%（23/101，95% CI 15.2–32.5）（P =.9); 严重的孕产妇和新生儿发病率也相似（分别为 2.9% 对 2.0% [ P =.7] 和 12.9% 对 9.9% [ P =.5]）。经过多变量逻辑回归和倾向评分加权分析（调整后的比值比 [aOR] 1.42，95% CI 0.62–3.24 [ P =.4]；和 aOR 1.34, 95% CI 0.53–3.38 [ P=.5]，分别）。试产组阴道分娩率在内口距离为 11-20 毫米的组中为 50.0% (19/38)，在距离为 1-10 毫米的组中为 18.5% (5/27) .

结论： 

我们的结果支持一项政策，即为妊娠 35 周且内口距离为 11-20 毫米的低位胎盘妇女提供试产。与 11-20 mm 相比，1-10 mm 的内口距离可显着降低阴道分娩的可能性，但不会增加严重 PPH 或严重产妇发病率的发生率。