College of Medicine and Health Sciences, University of Rwanda, Kigali, Rwanda.
University of Cape Town, Cape Town, Republic of South Africa.
PLoS One. 2022 Feb 15;17(2):e0263731. doi: 10.1371/journal.pone.0263731. eCollection 2022.
Postpartum haemorrhage (PPH) remains a major global burden contributing to high maternal mortality and morbidity rates. Assessment of PPH risk factors should be undertaken during antenatal, intrapartum and postpartum periods for timely prevention of maternal morbidity and mortality associated with PPH. The aim of this study is to investigate and model risk factors for primary PPH in Rwanda.
We conducted an observational case-control study of 430 (108 cases: 322 controls) pregnant women with gestational age of 32 weeks and above who gave birth in five selected health facilities of Rwanda between January and June 2020. By visual estimation of blood loss, cases of Primary PPH were women who changed the blood-soaked vaginal pads 2 times or more within the first hour after birth, or women requiring a blood transfusion for excessive bleeding after birth. Controls were randomly selected from all deliveries without primary PPH from the same source population. Poisson regression, a generalized linear model with a log link and a Poisson distribution was used to estimate the risk ratio of factors associated with PPH.
The overall prevalence of primary PPH was 25.2%. Our findings for the following risk factors were: antepartum haemorrhage (RR 3.36, 95% CI 1.80-6.26, P<0.001); multiple pregnancy (RR 1.83; 95% CI 1.11-3.01, P = 0.02) and haemoglobin level <11 gr/dL (RR 1.51, 95% CI 1.00-2.30, P = 0.05). During the intrapartum and immediate postpartum period, the main causes of primary PPH were: uterine atony (RR 6.70, 95% CI 4.78-9.38, P<0.001), retained tissues (RR 4.32, 95% CI 2.87-6.51, P<0.001); and lacerations of genital organs after birth (RR 2.14, 95% CI 1.49-3.09, P<0.001). Coagulopathy was not prevalent in primary PPH.
Based on our findings, uterine atony remains the foremost cause of primary PPH. As well as other established risk factors for PPH, antepartum haemorrhage and intra uterine fetal death should be included as risk factors in the development and validation of prediction models for PPH. Large scale studies are needed to investigate further potential PPH risk factors.
产后出血（PPH）仍然是一个全球性的重大负担，导致高孕产妇死亡率和发病率。应在产前、产时和产后期间评估 PPH 的危险因素，以便及时预防与 PPH 相关的孕产妇发病率和死亡率。本研究旨在调查和建模卢旺达原发性 PPH 的危险因素。
我们对 2020 年 1 月至 6 月期间在卢旺达五个选定的卫生设施分娩的 32 周及以上孕妇进行了一项观察性病例对照研究，共 430 名孕妇（108 例病例：322 名对照）。通过目测失血量，原发性 PPH 的病例为产后 1 小时内更换 2 次或更多次血浸阴道垫的妇女，或产后因出血过多需要输血的妇女。对照者是从同一源人群中随机选择的所有无原发性 PPH 的分娩者。使用泊松回归、具有对数链接和泊松分布的广义线性模型来估计与 PPH 相关的因素的风险比。
原发性 PPH 的总体患病率为 25.2%。我们发现以下危险因素的结果为：产前出血（RR 3.36，95%CI 1.80-6.26，P<0.001）；多胎妊娠（RR 1.83；95%CI 1.11-3.01，P=0.02）和血红蛋白水平<11g/dL（RR 1.51，95%CI 1.00-2.30，P=0.05）。在产时和即刻产后期间，原发性 PPH 的主要原因是：子宫收缩乏力（RR 6.70，95%CI 4.78-9.38，P<0.001），残留组织（RR 4.32，95%CI 2.87-6.51，P<0.001）；和产后生殖器器官裂伤（RR 2.14，95%CI 1.49-3.09，P<0.001）。凝血功能障碍在原发性 PPH 中并不常见。
根据我们的发现，子宫收缩乏力仍然是原发性 PPH 的首要原因。除了 PPH 的其他既定危险因素外，产前出血和宫内胎儿死亡应作为 PPH 预测模型开发和验证的危险因素。需要开展大规模研究以进一步调查潜在的 PPH 危险因素。
