Association of ambient temperature exposure during pregnancy with anxiety and depression symptoms in pregnant women

Objective To evaluate the effects of temperature and thermal humidity index exposure on maternal anxiety and depression symptoms during pregnancy.

Methods From June 2017 to December 2020, we conducted a prospective cohort study in the Guangzhou Panyu Maternal Child Health Hospital (Guangzhou Panyu District He Xian Memorial Hospital). A self-designed questionnaire was used to collect the demographic characteristics of pregnant women. The Self-Rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS) were used for psychological assessment. Daily meteorological data during the study period were collected and used to calculate the thermal humidity index (THI). A multiple linear regression model was used to evaluate the association of temperature/THI exposure with standardized SAS and SDS scores. A logistic regression model was used for assessing the association of temperature/THI exposure with maternal anxiety and depression.

Results A total of 5 553 pregnant women were included in this study. During the first, second, and third trimesters, 2 497, 2 709, and 857 participants finished the SAS assessment, respectively. The detection rates of anxiety symptoms were 13.1%, 8.9%, and 10.3%, respectively. Moreover, 2 554, 2 784, and 863 participants finished SDS assessment and the detection rates of depressive symptoms were 27.2%, 19.3%, and 18.9%, respectively. Regression models showed that during the second trimester, with per 5 ℃ increase in average ambient temperature at one week, two weeks, and one month before the survey, the standardized SAS score (95% confidence interval CI) decreased by 0.61 (-1.08, -0.13), 0.70 (-1.24, -0.16), and 0.75 (-1.44, -0.07), respectively. The odds ratios (95%CI) for the risk of anxiety were 0.71 (0.56, 0.91), 0.61 (0.46, 0.81), and 0.55 (0.38, 0.79), respectively. Similar associations were observed with THI exposure. Stratified analysis by survey seasons revealed that higher temperatures and THI during the cold season were associated with a decreased risk of anxiety during the second trimester. While higher temperatures and THI during the warm season were linked to a reduced risk of depression.

Conclusion Temperature exposure during pregnancy is associated with anxiety and depression symptoms, and these associations vary across seasons.