Environmental heat stress on maternal physiology and fetal blood flow in pregnant subsistence farmers in The Gambia, west Africa: an observational cohort study.
Environmental heat stress on maternal physiology and fetal blood flow in pregnant subsistence farmers in The Gambia, west Africa: an observational cohort study.
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DOI：
10.1016/s2542-5196(22)00242-x
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发表时间：
2022-12
期刊：
影响因子：
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通讯作者：
Haines A
中科院分区：
文献类型：
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作者：
Bonell A;Sonko B;Badjie J;Samateh T;Saidy T;Sosseh F;Sallah Y;Bajo K;Murray KA;Hirst J;Vicedo-Cabrera A;Prentice AM;Maxwell NS;Haines A
人为气候变化在全球范围内造成了极端气温，数据显示撒哈拉以南非洲特别容易受到这些变化的影响。在撒哈拉以南非洲，妇女占农业劳动力的50%，尽管高温暴露增加了不良生育结果的风险，但她们往往在整个怀孕期间工作。在这项研究中，我们的目的是提高认识的病理生理机制负责的不良健康结果造成的环境热应激怀孕自给农民。我们还旨在提供数据，以确定环境热应激是否也对胎儿产生生理影响。我们在伦敦卫生与热带医学院冈比亚医学研究理事会单位的野外站（名为MRC Keneba野外站），在冈比亚的西江进行了一项观察性队列研究。年龄在16岁或以上且任何妊娠或产次的妊娠<36周的孕妇被邀请参与研究。参与者有资格，如果他们参与农业或相关的手工日常生活任务。如果参与者拒绝提供知情同意书，有多胎妊娠（例如，如果他们有双胞胎），急性不适，或被诊断为先兆子痫或子痫，则不合格。采用湿球地球仪温度（WBGT）和通用热气候指数（UTCI）测量热应激，采用心率和皮肤温度计算的改良生理应变指数直接测量母体热应变。胎儿心率（FHR）和胎儿应变（定义为FHR >160次/分[bpm]或<115 bpm，或脐动脉阻力指数增加）的结局指标在休息和工作期间进行测量。多变量重复测量模型（FHR线性回归，胎儿应变逻辑回归）被用来评估热应激和热应变与急性胎儿应变的关联。在2019年8月26日至2020年3月27日期间，92名合格的参与者被招募到研究中。极端热暴露频繁，WBGT的平均暴露为27.2 °C（SD 3.6 °C），UTCI等效温度为34.0 °C（SD 3.7 °C）。UTCI对胎儿应变的总影响导致比值比（OR）为1.17（95%CI 1.09 - 1.29; p<0.0001），UTCI每升高1°C，校正后的直接影响OR为1.12（1.03 - 1.21; p= 0.010）。使用UTCI模型，每增加一个单位，母体热应激对胎儿应激的校正OR为1.20（1.01 - 1.43; p= 0.038）。我们的研究数据表明，减少母亲暴露于热应激和热应变可能会减少胎儿的应变，并有可能减少不良的出生结果。迫切需要进一步研究热应激与各种环境和人群中妊娠结局之间的关系，以制定有效的干预措施。Wellcome Trust。
Anthropogenic climate change has caused extreme temperatures worldwide, with data showing that sub-Saharan Africa is especially vulnerable to these changes. In sub-Saharan Africa, women comprise 50% of the agricultural workforce, often working throughout pregnancy despite heat exposure increasing the risk of adverse birth outcomes. In this study, we aimed to improve understanding of the pathophysiological mechanisms responsible for the adverse health outcomes resulting from environmental heat stress in pregnant subsistence farmers. We also aimed to provide data to establish whether environmental heat stress also has physiological effects on the fetus. We conducted an observational cohort study in West Kiang, The Gambia, at the field station for the Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine (named the MRC Keneba field station). Pregnant women who were aged 16 years or older and who were at <36 weeks’ gestation of any gravida or parity were invited to participate in the study. Participants were eligible if they were involved in agricultural or related manual daily tasks of living. Participants were ineligible if they refused to provide consent, had multiple pregnancies (eg, if they had twins), were acutely unwell, or were diagnosed with pre-eclampsia or eclampsia. Heat stress was measured by wet bulb globe temperature (WBGT) and by using the universal thermal climate index (UTCI), and maternal heat strain was directly measured by modified physiological strain index calculated from heart rate and skin temperature. Outcome measures of fetal heart rate (FHR) and fetal strain (defined as a FHR >160 beats per min [bpm] or <115 bpm, or increase in umbilical artery resistance index) were measured at rest and during the working period. Multivariable repeated measure models (linear regression for FHR, and logistic regression for fetal strain) were used to evaluate the association of heat stress and heat strain with acute fetal strain. Between Aug 26, 2019, and March 27, 2020, 92 eligible participants were recruited to the study. Extreme heat exposure was frequent, with average exposures of WBGT of 27·2°C (SD 3·6°C) and UTCI equivalent temperature of 34·0°C (SD 3·7°C). The total effect of UTCI on fetal strain resulted in an odds ratio (OR) of 1·17 (95% CI 1·09–1·29; p<0·0001), with an adjusted direct effect of OR of 1·12 (1·03–1·21; p=0·010) with each 1°C increase in UTCI. The adjusted OR of maternal heat strain on fetal strain was 1·20 (1·01–1·43; p=0·038), using the UTCI model, with each unit increase. Data from our study show that decreasing maternal exposure to heat stress and heat strain is likely to reduce fetal strain, with the potential to reduce adverse birth outcomes. Further work that explores the association between heat stress and pregnancy outcomes in a variety of settings and populations is urgently needed to develop effective interventions. The Wellcome Trust.