Association of maternal exposure to compound hot extreme during pregnancy with preterm birth and the potential biological mechanisms in Guangzhou

He Zhou; Zhixing LI; Guimin Chen; Xin Liu; Moran Dong; Jiaqi Wang; Dengzhou Chen; Jianpeng Xiao; Guanhao HE; Jianxiong HU; Zuhua Rong; Wenjun MA; Tao Liu

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Association of maternal exposure to compound hot extreme during pregnancy with preterm birth and the potential biological mechanisms in Guangzhou

VernacularTitle:广州市孕妇孕期日夜复合热暴露与早产的关联及机制
Author: He ZHOU ^{1
,

2} ; Zhixing LI ^{1
,

3} ; Guimin CHEN ^{1
,

4} ; Xin LIU ⁵ ; Moran DONG ⁵ ; Jiaqi WANG ⁵ ; Dengzhou CHEN ⁵ ; Jianpeng XIAO ⁵ ; Guanhao HE ⁵ ; Jianxiong HU ⁵ ; Zuhua RONG ⁵ ; Wenjun MA ^{1
,

3} ; Tao LIU ^{1
,

3}
Author Information

1. Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, Guangdong 511430, China
2. School of Public Health, Guangdong Pharmaceutical University, Guangzhou, Guangdong 510310, China.
3. School of Medicine, Jinan University, Guangzhou, Guangdong 510632, China.
4. School of Public Health, Southern Medical University, Guangzhou, Guangdong 510515, China.
5. Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, Guangdong 511430, China.
Publication Type:Specialcolumn:Mechanismsunderlyinghumanhealtheffectsofclimatechange
Keywords: compound hot extreme; preterm birth; biological mechanism; birth cohort study
From: Journal of Environmental and Occupational Medicine 2022;39(3):289-295
CountryChina
Language:Chinese
Abstract: Background Global warming may increase the frequency of compound hot extreme (CHE).However, there is still a lack of studies assessing the associations between CHE and preterm birth (PTB), and the underlying biological mechanisms remain unclear. Objective To estimate the association of exposure to CHE during pregnancy with PTB, and to explore the roles of inflammatory, endothelial dysfunction, and oxidative stress in the association between CHE and PTB. Methods All participants were selected from the Prenatal Environments and Offspring Health (PEOH), a prospective birth cohort conducted in Guangzhou. In this study, a total of 2449 participants who gave birth from May to October in 2014 to 2017 were enrolled, and among them blood samples were collected from 311 preterm (n=43) and full-term (n=268) pregnant women at the time of delivery. A hot day/night was identified as a day when the daily maximum temperature/minimum temperature was higher than its 90th percentile in the study period, and a CHE was defined as having both a hot night and a following hot day. The meteorological data were obtained from the China Meteorological Data Sharing Service System. Anusplin was used to assess the daily maximum temperature, daily minimum temperature, and relative humidity of the participant residence. Enzyme-linked immunosorbent assay (ELISA) was used to measure C reactive protein (CRP), endothelin-1 (ET-1), and malondialdehyde (MDA) levels in maternal serum, and their results were transformed by natural logarithm. A distributed lag nonlinear model was used to investigate the associations of exposures to hot day, hot night, and CHE during pregnancy with PTB at different lag days, and a logistic regression model was used to investigate the associations of CRP, ET-1, and MDA with PTB. Results The incidence rate of PTB was 6.2% in all selected participants. Compared with the non-hot day, the RRs (95%CIs) of CHE in lag 3, 7, and 14 days on PTB were 1.43 (1.12-1.84), 1.24 (1.08-1.43), and 1.17 (1.05-1.30), respectively, and the cumulative effects (% difference) (95%CI) of CHE in lag 14 days on maternal serum CRP, ET-1, and MDA were 0.33% (−0.45%-1.12%), 0.59% (0.11%-1.07%), and 0.57% (0.09%-1.05%), respectively. Compared with the Q1 (lowest quartile) for CRP, ET-1 and MDA, the RRs (95%CIs) of Q4 (highest quartile) for PTB were 1.27 (0.50-3.22), 1.51 (0.61-3.72), and 2.07(0.81-5.27), respectively. Conclusion Maternal exposure to CHE during pregnancy might be associated with an increased risk of PTB. Prenatal exposure to CHE is positively associated with maternal serum CRP, ET-1, and MDA, and the three biochemical indicators are also positively associated with PTB. However, the above conclusions still need further confirmation.