Can Temperature Affect Maternal Stress During Pregnancy?

Abstract

Background/Aim: Maternal psychological stress during pregnancy has essentially been conceptualized as a teratogen. However, little is known about the effect of temperature on maternal stress during pregnancy. The aim of this study is to investigate the relationship between temperature and maternal stress during pregnancy. Methods: In 2010, a total of 1931 eligible pregnant women were enrolled across Shanghai from four prenatal care clinics during their mid-to-late pregnancy. Maternal life-event stress and emotional stress levels during pregnancy were assessed by the "Life Event Scale for Pregnant Women" (LESPW) and "Symptom Checklist-90-Revised Scale" (SCL-90-R), respectively. Multivariate binary logistic regression models were used to evaluate the relationship between temperature and maternal stress. Stratified analyses were conducted to identify the modifying effects of complications of pregnancy and sunlight duration on the association between temperature and maternal stress. Results: After adjusting for relevant confounders, an U-shaped relationship was observed between the daily average temperature and maternal Global-Severity-Index (GSI) of the SCL-90-R. The risk of high GSI (P75-P100) increased when the women were exposed to extreme low temperatures (P1-P5) (OR=1.7, 95% CI: 1.1-2.7) and extreme high temperatures (P95-P100) (OR=1.6, 95% CI: 1.1-2.4) compared to the risk when they were exposed to an optimal temperature range (20-25°). High temperatures induced acute stress (lasted for 1 day), whereas low temperatures induced long-term stress (lasted for 14 days). Women without complications of pregnancy were more susceptible to extreme low or high temperatures than those with complications of pregnancy. When exposed to extreme low or high temperatures, women experiencing short (vs. long) sunlight duration were more likely to develop high GSI (P75-P100). Conclusions: In conclusion, extreme low (P1-P5) and high (P95-P100) temperatures may induce acute and long-term emotional stress during pregnancy, respectively. Complications of pregnancy and sunlight duration may modify the relationship between temperature and maternal stress during pregnancy.