BackgroundGlobal 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.ObjectiveTo 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.MethodsAll 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.ResultsThe 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.ConclusionMaternal 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.

[背景]硒(Se)是人体必需的元素,但过量的硒会产生毒性.孕妇孕期硒暴露水平与胎儿发育的关系目前尚不明确.[目的]了解广州市孕妇孕期硒暴露与孕晚期胎儿头围的关系.[方法]所有孕妇均来自2016年起在广州进行的产前环境与后代健康(PEOH)队列.研究对象分别在孕早期(孕周≤13周)完成基线调查并建立随访档案,在孕晚期(孕周≥28周)进行随访.调查包括面对面采访的问卷调查并从医院信息系统中提取孕妇的产前护理记录,另分别收集孕早期和孕晚期孕妇各15.0mL尿液,孕晚期对胎儿进行超声检查,记录胎儿头围的生长发育情况.根据是否提供尿样及所有资料的完整性,孕早期和孕晚期分别剔除部分对象后,研究共纳入2 739名孕妇;其中孕早期和孕晚期各纳入孕妇2138、1383名,分别分析孕早、晚期孕妇硒暴露与孕晚期胎儿头围的关系.尿硒浓度(ωSe)通过尿肌酐校正(计量单位为:μg·g-1,以肌酐计,后同),并经自然对数转换为InωSe.调整孕妇年龄、受教育程度、家庭收入和孕前体重指数、孕次、孕周数、胎儿性别、二手烟暴露、钙片的摄入、肉与海鲜的摄入等因素后,应用多重线性回归模型估算孕妇硒暴露水平与胎儿头围之间的关系,并进一步分性别进行分析.[结果]在2739名孕妇中,年龄≥30岁的有1926人(70.3％),男胎有1474人(53.8％),受教育程度在高中及以上的有2313人(84.4％),怀孕期间有二手烟暴露的871人(31.8％),孕周≥37周的有2637人(96.3％).孕早期和孕晚期孕妇的硒暴露水平的中位数及第25、75百分位数分别为38.5(30.1,44.5)μg·g-1 和38.9(28.7,54.0)μg·g-1.孕晚期胎儿头围为(218.1±41.4)mm.经多重线性回归模型分析,未观察到孕早期的硒暴露与孕晚期胎儿头围的关联有统计学意义.但孕晚期孕妇尿InωSe每增加一个单位,胎儿头围减小值及其95％可信区间(CI)为7.04(3.41～10.67)mm(P＜0.001).在孕晚期,孕妇硒暴露根据InωSe的四分位数分为四组(Q1～Q4),与Q1组相比,Q4组者胎儿的头围减小19.47(12.50～26.43)mm(P＜0.001).孕晚期孕妇尿中InωSe每增加一个单位,男胎和女胎的头围分别减小5.06(0.48～9.63)mm(P=0.031)、11.30(5.32～17.27)mm(P＜0.001),且男女差异为6.24(1.69～10.79)mm;与硒暴露Q1组相比,Q4组者男胎和女胎的头围分别减小18.13(8.45～27.81)mm、21.26(11.23～31.30)mm(均P＜0.001).[结论]在本人群的暴露水平下,孕晚期孕妇较高尿硒水平与孕晚期胎儿头围减小有关.

目的 了解广州市孕妇PM2.5暴露与其孕晚期尿和血中白细胞水平的暴露反应关系,明确其易感暴露窗口.方法 根据前期在广州建立的一项出生队列研究(PEOH研究),采用时空土地利用回归模型估算孕妇从怀孕前13周至其孕晚期采样周的每周PM2.5暴露水平.分别使用Cox比例风险模型嵌套的分布滞后非线性模型和分布滞后非线性模型估计孕妇每周PM25暴露与其尿白细胞阳性风险和血白细胞计数之间的暴露反应关系.结果 本次研究纳入了3753名孕妇.孕妇在第20～27孕周PM2.5暴露与尿白细胞阳性呈正相关,且在第24孕周效应最强,PM2.5每增加10 μg/m3,HR为1.030(95％ CI:1.007～1.054).孕妇在孕前第5周至第6孕周的PM2.5暴露与血白细胞计数呈正相关,且在末次月经当周效应最强,PM2.5每增加10μg/m3,血白细胞计数增加0.22％(95％ CI:0.10％～0.35％).结论 孕妇孕期暴露于PM2.5与孕晚期尿白细胞阳性风险升高和血白细胞计数升高有关,易感暴露窗口分别为第20～27孕周和孕前第5周至第6孕周.

Background: Previous studies have demonstrated the embryotoxicity and fetotoxicity of thallium (Tl). However, the effects of prenatal exposure to Tl on birth weight and placental weight and the mediating role of placental weight in the association of Tl with birth weight remain unclear. Methods: We recruited 2,748 participants from the ongoing Prenatal Environment and Offspring Health Cohort (PEOH Cohort) study, which was initiated in 2016 in Guangzhou, China. The Tl concentrations in maternal urine samples collected during the first and third trimester were determined by inductively coupled plasma mass spectrometry. Birth weight and placental weight were extracted from maternal medical records. Results: Pregnant women exposed to the highest tertile of Tl in the first trimester (β = −42.7 g, 95% CI: −82.3, −3.1 g) and third trimester (β = −50.6 g, 95% CI: −99.0, −2.3 g) had babies with lower birth weights than those exposed to the lowest tertile. We also found significant negative associations of exposure to Tl concentrations in the first and third trimester with placental weight. Mediation analyses showed that 50.3% (95% CI: 15.9, 79.2%) and 33.5% (95% CI: 1.3, 80.3%) of the effects of Tl exposure in the first and third trimester on birth weight were mediated by decreased placental weight. Conclusion: Our results suggest that prenatal exposure to Tl is negatively associated with birth weight and that this association may be mediated by decreased placental weight.

目的 探索孕妇孕期烧香对出生体重和胎盘重量的影响,为降低不良妊娠结局的发生风险提供依据.方法 基于前瞻性出生队列,在医院产科门诊和住院部收集资料,采用多重线性回归模型分析孕妇佛香和蚊香焚烧暴露与出生体重和胎盘重量的关系.结果 共纳入4 038对母婴.与无佛香暴露者相比,高频烧佛香的孕妇胎盘重量降低5.43 g(95％CI:-9.94～-0.91).与无蚊香暴露者相比,蚊香暴露为高频孕妇的新生儿出生体重降低56.76 g(95％CI:-110.31～-3.22).结论 孕妇孕期应减少室内烧香暴露,避免其引起的出生体重和胎盘重量下降.

Background: The ongoing COVID-19 pandemic has brought significant challenges to health system and consumed a lot of health resources. However, evidence on the hospitalization costs and their associated factors in COVID-19 cases is scarce. Objectives: To describe the total and components of hospitalization costs of COVID-19 cases, and investigate the associated factors of costs. Methods: We included 876 confirmed COVID-19 cases admitted to 33 designated hospitals from January 15th to April 27th, 2020 in Guangdong, China, and collected their demographic and clinical information. A multiple linear regression model was performed to estimate the associations of hospitalization costs with potential associated factors. Results: The median of total hospitalization costs of COVID-19 cases was $2,869.4 (IQR: $3,916.8). We found higher total costs in male (% difference: 29.7, 95% CI: 15.5, 45.6) than in female cases, in older cases than in younger ones, in severe cases (% difference: 344.8, 95% CI: 222.5, 513.6) than in mild ones, in cases with clinical aggravation than those without, in cases with clinical symptoms (% difference: 47.7, 95% CI: 26.2, 72.9) than those without, and in cases with comorbidities (% difference: 21.1%, 21.1, 95% CI: 4.4, 40.6) than those without. We also found lower non-pharmacologic therapy costs in cases treated with traditional Chinese medicine (TCM) therapy (% difference: -47.4, 95% CI: -64.5 to -22.0) than cases without. Conclusion: The hospitalization costs of COVID-19 cases in Guangdong were comparable to the national level. Factors associated with higher hospitalization costs included sex, older age, clinical severity and aggravation, clinical symptoms and comorbidities at admission. TCM therapy was found to be associated with lower costs for some non-pharmacologic therapies.

Although previous studies have proposed an association between maternal exposure to fine particulate matter (PM2.5) and the risk of gestational diabetes mellitus (GDM), such evidence remains rare. Additionally, the effects of PM2.5 on glycemic control in GDM patients are poorly known. In this study, we conducted a prospective birth cohort study in China, and aimed to investigate the association between maternal exposure to PM2.5 and the risk of GDM, identify the susceptible exposure window, and quantify the exposure-response relationships between PM2.5 and fasting glucose in GDM patients. A spatiotemporal land-use-regression model was used to estimate individual weekly PM2.5 exposure during pregnancy. A distributed lag nonlinear model incorporated with a Cox proportional hazard model was used to estimate the association between maternal exposure to PM2.5 and the risk of GDM. Among the 4174 pregnant women in our study, 1018 (24.4%) were diagnosed with GDM. Each 10 μg m−3 increment in PM2.5 exposures during the 24th gestational week was significantly associated with a higher risk of GDM [hazard ratio (HR) = 1.03, 95% CI (confidence interval): 1.01, 1.06]. Compared to the lowest quartile (Q1) of PM2.5 exposure, participants with the highest quartile (Q4) during the 21st–24th gestational weeks had a higher risk of GDM, and the strongest association was observed in the 22nd gestational week (HR = 1.15, 95%Cl: 1.02, 1.28). The mean PM2.5 exposures during the 21st–24th weeks were positively associated with fasting plasma glucose in pregnant women with GDM. Each 10 μg m−3 increase in the mean PM2.5 exposure was associated with a 0.07 mmol l−1 (95% CI: 0.04, 0.11 mmol l−1) increase in the fasting glucose level. Our findings suggest that maternal exposure to higher PM2.5 during pregnancy may increase the risk of GDM, and result in poor glycemic control among pregnant women with GDM. The 21st–24th gestational week period might be the (most)? susceptible exposure window of PM2.5.

Background: Strict lockdown measurements implemented during the COVID-19 pandemic have dramatically reduced the anthropogenic-based emissions in China. We aimed to comprehensively describe air pollution during and after the COVID-19 lockdown in China, and to estimate the mortality burden related to the air pollution changes. Methods: We analyzed national air quality monitoring and mortality data to describe the changes of air pollutants, and to estimate the health impact from air pollution changes during and after the lockdown periods in 2020 compared with 2018-2019. Changes in number of deaths and years of life lost (YLL) were used as indicators in the estimations. Findings: The mean air quality index (AQI), PM10, PM2·5, NO2, SO2 and CO concentrations during the lockdown period in 2020 across China declined by 18·2 (21·2%), 27·0μg/m3 (28·9%), 10.5μg/m3 (18·3%), 8·4μg/m3 (44·2%), 13·1μg/m3 (38·8%), and 0·3mg/m3 (27·3%) respectively, when compared to the same periods during 2018-2019 . We observed an increase in O3 concentration during the lockdown by 5·5μg/m3 (10·4%), and a slight decrease after the lockdown by 3·4μg/m3 (4·4%). As a result, there were 51·3 (95%CI: 32·2, 70·1) thousand fewer premature deaths (16·2 thousand during and 35·1 thousand after the lockdown), and 1,066·8 (95%CI: 668·7, 1,456·8) thousand fewer YLLs (343·3 thousand during and 723·5 thousand after the lockdown) than these in 2018-2019 in China. Interpretation: The COVID-19 lockdown has caused substantial decrease in air pollutant concentrations except for O3, which has been accompanied by substantial mortality reductions in China. Funding: Key-Area Research and Development Program of Guangdong Province. Declaration of Interests: We declare no competing interests. Ethics Approval Statement: This study was approved by the Ethics Committee of Guangdong Provincial Center for Disease Control and Prevention (W96-027E-2020004).

目的 探讨组蛋白去乙酰化酶(histone deacetylase,HDACs)的3个单核苷酸多态性位点与2型糖尿病(type 2 diabetes mellitus,T2DM)的关联,以及各位点与环境间交互作用对T2DM易感性的影响,为T2DM预防和治疗提供依据.方法 2017年在广州市花都区17个行政村和2个社区居委中随机抽取10个村做基线调查后选取T2DM者为病例组,以同性别、年龄相差不超过5岁和来源于同一行政村为条件,1∶1个体匹配方法匹配对照组.采用条件Logistic回归分析模型分析基因和环境及其交互作用对T2DM的影响.结果 共调查499名病例,平均年龄(61.53±13.08)岁,男性占37.88％;499名对照的平均年龄(61.48±13.09)岁,男性占37.88％.甘油三酯(triglyceride,TG)异常(OR=2.410,95％ CI:1.755～3.310,P＜0.001)和总胆固醇(total cholesterol,TC)异常(OR=1.436,95％ CI:1.046～1.972,P=0.025)是T2DM的危险因素.rs72792338 TT+TC基因型携带(OR=0.526,95％ CI:0.349～0.793,P=0.002)是T2DM的保护因素.结论 甘油三酯和总胆固醇异常是T2DM的危险因素,rs72792338TT和TC基因型携带是T2DM的保护因素,未发现HDACs基因与环境对T2DM的影响存在交互作用.

Although studies have assessed the associations between prenatal exposure with fine particulate matter (PM) with birth weight, few have investigated the effect of PM1 exposure and identified the susceptible exposure window. Additionally, a baby boom occurred after China implemented the universal two-child policy, but whether the effects of PM are modified by birth order remains unknown. The objective of this study was to estimate the effects of prenatal exposure to PM (PM2.5 and PM1) on birth weight, identify the susceptible exposure windows, and assess the modifying effect of birth order on the effects of PM exposure. All participants were selected from the Prenatal Environment and Offspring Health (PEOH) cohort conducted since 2016 in Guangzhou, China. A spatiotemporal land-use-regression (STLUR) model was used to estimate a pregnant woman's weekly PM2.5 exposure, and a generalized additive model (GAM) was used to estimate each PM1 exposure. A distributed lag non-linear model (DLNM) was applied to assess the exposure-lag-response associations between weekly PM exposure and birth weight. The sample included 4086 pregnant women. The results showed that maternal exposure to PM2.5 and PM1 during the 15th to 24th and 16th to 24th gestational weeks were associated with lower birth weight, the strongest association was observed in the 19th week, during which each 10 mu g/m(3) increment in PM2.5 and PM1 was associated with a 1.47 g (95% CI: 2.49 g, 0.44 g) and 1.58 g (95%CI: 2.74 g, 0.41 g) decrease in birth weight, respectively. Compared with the first-born neonates, greater effects of PM2.5 and PM1 exposure on birth weight were observed among the second-born neonates in the 15th to 21st and 15 h to 22nd gestational weeks. Further studies tracking the health of the second-born children are warranted because they may be more sensitive to environmental factors than the first-born children.

Maternal exposures to ambient temperatures during pregnancy may increase the preterm birth (PTB) risk; however, which periods have stronger effects remain controversial. The effects of temperature exposure on PTB in first- and second-born neonate groups may be different during the new baby boom that has followed the Two-child Policy in China. We examined a birth cohort of 4928 pregnant women beginning in 2016 in Guangzhou, China. An inverse distance weighted method was used to estimate the temperature exposure at each individual residential address. A distribution lag non-linear model incorporating a Cox proportional hazard model was employed to estimate the effects of temperature exposure on PTB and test the effects modification of birth order related to the new baby boom. A total of 4101 pregnant women were included, of which 234 (5.7%) experienced PTB. Compared with the mean temperature (23.0 °C), we found a significantly higher risks of PTB associated with high temperatures (i.e, 30 °C [95th centile]) from the 4th to 8th, and 22nd to 27th gestational weeks. A peak effect was found during the 6th week (HR = 1.79, 95% CI: 1.26, 2.54) and 24th week (HR = 1.83, 95% CI: 1.27, 2.62). The risks of PTB were reduced for low temperatures (i.e. 14 °C [5th centile] versus 23.0 °C) from the 2nd to 10th and 20th to 26th gestational weeks, and the negative peak effect was found during the 4th week (HR = 0.43, 95% CI: 0.26, 0.72) and 23rd week (HR = 0.59, 95% CI: 0.43, 0.83). Stratification analyses showed that significant effects of 30 °C versus 23 °C on PTB were observed during the 4th to 8th weeks in the second-born neonate, and the peak effect was found in the 6th week (HR = 2.13, 95% CI: 1.31, 3.47). However, we did not find significant effects of 30 °C during the same weeks in the first-born neonate group. Maternal exposures to higher temperatures during pregnancy may increase the risk of PTB, and lower temperatures may decrease the risk of PTB. Stronger effects of temperature exposures during the first trimester on PTB risk were found among the second-born neonates than among the first-born neonates.

Although studies have assessed the associations of maternal exposure to ozone (O3) during pregnancy with blood pressure and the risk of hypertensive disorders of pregnancy (HDP), the results were inconsistent. Furthermore, no studies have been conducted in China where the ambient O3 concentration continuedly increased. The present study aimed to estimate the effects of maternal exposure to O3 during pregnancy on the HDP risk, systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP). All participants of pregnant women were selected from the prospective birth cohort study on Prenatal Environments and Offspring Health conducted in Guangzhou, China. A spatiotemporal land-use-regression model was used to estimate individual monthly air pollution exposure from three months before pregnancy to childbirth date. Information on HDP, SBP, DBP and PP was obtained from maternal medical records. A Logistic regression model and a mixed linear model were used to estimate the associations of maternal exposure to O3 with the risk of HDP and blood pressure (SBP, DBP and PP), respectively. We found significant associations of maternal exposure to O3 during the third (OR = 1.31, 95%CI: 1.07, 1.60) and the second month (OR = 1.25, 95%CI: 1.02, 1.51) before pregnancy with the risk of HDP. Observed significantly positive associations of O3 exposures with SBP, DBP and PP during the two months before pregnancy and during the early pregnancy. The peak effects of O3 exposure on SBP, DBP and PP were respectively observed during the second month of pregnancy (β = 1.07  mmHg, 95%CI: 0.84, 1.31  mmHg), the first month before pregnancy (β = 0.40  mmHg, 95%CI: 0.21, 0.50  mmHg) and the second month of pregnancy (β = 0.78  mmHg, 95%CI: 0.59, 0.97  mmHg). Our results suggest that maternal exposure to O3 were positively associated with blood pressure and the risk of HDP, and the period from three months before pregnancy to the first trimester might be the critical exposure window.

Background: The placenta performs crucial functions to ensure normal fetal development. Experimental studies have indicated associations between exposure to elevated temperatures during pregnancy and reduction in placental weight and volume. However, epidemiological studies in humans are lacking. Objective: To estimate the associations between prenatal exposure to ambient temperature with placental weight, volume, and the placental weight to birth weight ratio (PFR). Methods: We conducted a prospective birth cohort study using the Prenatal Environment and Offspring Health Cohort (PEOH Cohort) beginning in 2016 in Guangzhou, China. Women in early pregnancy were recruited and followed up during their hospitalization for childbirth. An inverse distance-weighted method was employed to estimate the average temperature exposure of every 4 weeks as well as the trimester-specific average temperature exposure at the individual's residential address. A generalized linear model was applied to estimate the effects of temperature exposure during pregnancy on the placental weight, volume, and PFR. Results: A total of 4051 pregnant women were enrolled. Compared with the reference temperature of 20 degrees C, maternal exposure to 29 degrees C (95th centile) during late pregnancy was associated with an average of -6.03 g (95% confidence interval [CI]: -11.28 g, -0.78 g) in placental weight, -16.15 cm(3) (95% CI: -26.24 cm(3), -6.07 cm(3)) in placental volume, and 0.26 (95% CI: 0.07, 0.45) in PFR. The peak effects of high temperatures on placental weight, volume, and PFR were found from 29 to 32 weeks (beta = -3.79 g, 95% CI: -8.39 g, 0.82 g), 37 to 40 weeks (beta = -19.34 cm(3), 95% CI: -30.99 cm(3), -7.69 cm(3)), and 25 to 28 weeks (beta= 0.35, 95% CI: 0.04, 0.66), respectively. Conclusions: Maternal exposure to elevated temperatures was associated with a decrease in placental weight and volume and an increase in PFR. The associations were stronger when exposures occurred during late pregnancy.

The aim of this study was to estimate the weekly time-weighted (outdoor and indoor activity patterns) individual exposure to particulate air pollutants (PM10, PM2.5 and PM1) of pregnant women. A total of 4928 pregnancy women were recruited during their early pregnancy, and 4278 (86.8%) were successfully followed-up at childbirth. Each individual weekly average PM10 and PM2.5 concentrations at the residential and workplace addresses from three months before pregnancy to childbirth was estimated using a spatiotemporal land use regression (ST-LUR) model, and the weekly PM1 concentration was estimated employing a generalized additive model (GAM) which utilized weekly PM2.5 and meteorological factors as independent predictors. Then, the time-weighted individual exposure to particulate air pollutants during workdays and non-workdays during the period from three months before pregnancy to childbirth was estimated based on the estimated weekly air pollutant concentrations and each participant's indoor and outdoor activity model, respectively. Data analysis was carried out by R software (version 3.5.1) and packages "SpatioTemporal", "mgcv" and "splines" were mainly used. This method takes a full consideration of indoor and outdoor activity patterns in the individual exposure to particulate air pollutants. •A ST-LUR model was used to estimate the individual weekly average PM10 and PM2.5 concentrations at their residential and workplace addresses.•A GAM was applied to estimate the weekly average PM1 concentration at individual residential and workplace addresses.•Individual weekly exposure to particulate air pollutants during workdays and non-workdays was assessed based on the estimated particulate air pollutant concentrations and their indoor and outdoor activity model.