Jiaqi Wang1, Xin Liu1, Moran Dong1, Xiaoli Sun2, Jianpeng Xiao1, Weilin Zeng1, Jianxiong Hu1, Xing Li1, Lingchuan Guo1, Zuhua Rong1, Guanhao He1, Jiufeng Sun1, Dan Ning1, Dengzhou Chen1, Yonghui Zhang3, Bo Zhang4, Wenjun Ma1, Tao Liu5. 1. Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China. 2. Gynecology Department, Guangdong Women and Children Hospital, Guangzhou 511442, China. 3. Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China. 4. Food Safety and Health Research Center, School of Public Health, Southern Medical University, Guangzhou 510515, China. 5. Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou 511430, China. Electronic address: gztt_2002@163.com.
Abstract
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 °C, maternal exposure to 29 °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 cm3 (95% CI: -26.24 cm3, -6.07 cm3) 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 (β = -3.79 g, 95% CI: -8.39 g, 0.82 g), 37 to 40 weeks (β = -19.34 cm3, 95% CI: -30.99 cm3, -7.69 cm3), and 25 to 28 weeks (β = 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.
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 °C, maternal exposure to 29 °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 cm3 (95% CI: -26.24 cm3, -6.07 cm3) 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 (β = -3.79 g, 95% CI: -8.39 g, 0.82 g), 37 to 40 weeks (β = -19.34 cm3, 95% CI: -30.99 cm3, -7.69 cm3), and 25 to 28 weeks (β = 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.
Authors: Xinye Qiu; Kelvin C Fong; Liuhua Shi; Stefania Papatheodorou; Qian Di; Allan Just; Anna Kosheleva; Carmen Messerlian; Joel D Schwartz Journal: Environ Epidemiol Date: 2020-09-14
Authors: Yohani Dalugoda; Jyothi Kuppa; Hai Phung; Shannon Rutherford; Dung Phung Journal: Int J Environ Res Public Health Date: 2022-02-04 Impact factor: 3.390