Lancet Glob Health. 2023 Aug;11(8):e1249-e1259. doi: 10.1016/S2214-109X(23)00245-0. Epub 2023 Jun 27.
Worldwide, more than half a billion women of reproductive age are anaemic. Each year, about 70 000 women who give birth die from postpartum haemorrhage. Almost all deaths are in low-income or middle-income countries. We examined the association between anaemia and the risk of postpartum haemorrhage.
We did a prospective cohort analysis of data from the World Maternal Antifibrinolytic-2 (WOMAN-2) trial. This trial enrols women with moderate or severe anaemia giving birth vaginally in hospitals in Pakistan, Nigeria, Tanzania, and Zambia. Moderate anaemia was defined as a haemoglobin concentration of 70-99 g/L and severe anaemia as less than 70 g/L. Hospitals in each country where anaemia in pregnancy is common were identified from a network established during previous obstetric trials. Women who were younger than 18 years without permission provided by a guardian, had a known tranexamic acid allergy, or developed postpartum haemorrhage before the umbilical cord was cut or clamped were excluded from the study. Prebirth haemoglobin, the exposure, was measured after hospital arrival and just before giving birth. Postpartum haemorrhage, the outcome, was defined in three ways: (1) clinical postpartum haemorrhage (estimated blood loss ≥500 mL or any blood loss sufficient to compromise haemodynamic stability); (2) WHO-defined postpartum haemorrhage (estimated blood loss of at least 500 mL); and (3) calculated postpartum haemorrhage (calculated estimated blood loss of ≥1000 mL). Calculated postpartum haemorrhage was estimated from the peripartum change in haemoglobin concentration and bodyweight. We used multivariable logistic regression to examine the association between haemoglobin and postpartum haemorrhage, adjusting for confounding factors.
Of the 10 620 women recruited to the WOMAN-2 trial between Aug 24, 2019, and Nov 1, 2022, 10 561 (99·4%) had complete outcome data. 8751 (82·9%) of 10 561 women were recruited from hospitals in Pakistan, 837 (7·9%) from hospitals in Nigeria, 525 (5·0%) from hospitals in Tanzania, and 448 (4·2%) from hospitals in Zambia. The mean age was 27·1 years (SD 5·5) and mean prebirth haemoglobin was 80·7 g/L (11·8). Mean estimated blood loss was 301 mL (SD 183) for the 8791 (83·2%) women with moderate anaemia and 340 mL (288) for the 1770 (16·8%) women with severe anaemia. 742 (7·0%) women had clinical postpartum haemorrhage. The risk of clinical postpartum haemorrhage was 6·2% in women with moderate anaemia and 11·2% in women with severe anaemia. A 10 g/L reduction in prebirth haemoglobin increased the odds of clinical postpartum haemorrhage (adjusted odds ratio [aOR] 1·29 [95% CI 1·21-1·38]), WHO-defined postpartum haemorrhage (aOR 1·25 [1·16-1·36]), and calculated postpartum haemorrhage (aOR 1·23 [1·14-1·32]). 14 women died and 68 either died or had a near miss. Severe anaemia was associated with seven times higher odds of death or near miss (OR 7·25 [95% CI 4·45-11·80]) than was moderate anaemia.
Anaemia is strongly associated with postpartum haemorrhage and the risk of death or near miss. Attention should be given to the prevention and treatment of anaemia in women of reproductive age.
The WOMAN-2 trial is funded by Wellcome and the Bill & Melinda Gates Foundation.
全球有超过 5 亿育龄期女性贫血。每年约有 7 万名产妇死于产后出血。几乎所有的死亡都发生在低收入和中等收入国家。我们研究了贫血与产后出血风险之间的关系。
我们对来自全球妇女抗纤维蛋白溶解剂-2（WOMAN-2）试验的前瞻性队列数据进行了分析。该试验招募了在巴基斯坦、尼日利亚、坦桑尼亚和赞比亚的医院分娩的中度或重度贫血的女性。中度贫血定义为血红蛋白浓度 70-99 g/L，重度贫血定义为血红蛋白浓度<70 g/L。从之前的产科试验中建立的网络中确定了每个国家中妊娠贫血常见的医院。未获得监护人许可、已知对氨甲环酸过敏或脐带夹闭前发生产后出血的年龄小于 18 岁的妇女被排除在研究之外。产前血红蛋白（暴露因素）是在医院到达后和分娩前测量的。产后出血（结局）有三种定义方式：（1）临床产后出血（估计失血量≥500 mL 或任何足以导致血流动力学不稳定的失血）；（2）世界卫生组织定义的产后出血（估计失血量至少 500 mL）；（3）计算产后出血（估计失血量≥1000 mL）。计算产后出血是根据围产期血红蛋白浓度和体重的变化来估计的。我们使用多变量逻辑回归来检查血红蛋白与产后出血之间的关系，并调整了混杂因素。
在 2019 年 8 月 24 日至 2022 年 11 月 1 日期间招募到 WOMAN-2 试验的 10620 名女性中，有 10561 名（99.4%）有完整的结局数据。来自巴基斯坦医院的 8751 名（82.9%）、尼日利亚医院的 837 名（7.9%）、坦桑尼亚医院的 525 名（5.0%）和赞比亚医院的 448 名（4.2%）女性被招募。平均年龄为 27.1 岁（标准差 5.5），平均产前血红蛋白为 80.7 g/L（标准差 11.8）。对于 8791 名（83.2%）中度贫血的女性，平均估计失血量为 301 mL（标准差 183），对于 1770 名（16.8%）重度贫血的女性，平均估计失血量为 340 mL（标准差 288）。有 742 名（7.0%）女性发生临床产后出血。中度贫血女性发生临床产后出血的风险为 6.2%，重度贫血女性为 11.2%。产前血红蛋白每降低 10 g/L，临床产后出血的可能性增加（调整后的优势比[aOR] 1.29[95%CI 1.21-1.38]）、世界卫生组织定义的产后出血（aOR 1.25[1.16-1.36]）和计算产后出血（aOR 1.23[1.14-1.32]）。有 14 名女性死亡，68 名女性死亡或接近死亡。与中度贫血相比，重度贫血与死亡或接近死亡的风险增加了 7 倍（比值比[OR] 7.25[95%CI 4.45-11.80]）。
贫血与产后出血以及死亡或接近死亡的风险密切相关。应重视育龄期女性贫血的预防和治疗。
WOMAN-2 试验由威康信托基金会和比尔及梅琳达·盖茨基金会资助。
