Ambient temperature and preeclampsia: A historical cohort study

Area of Science:

• Environmental Epidemiology
• Reproductive Health
• Climate Change Adaptation

Background:

• Inconsistent associations between ambient temperature and preeclampsia risk reported in prior studies.
• Potential impact of temperature-related preeclampsia on the global health burden, particularly with ongoing climate change.

Purpose of the Study:

• To investigate the association between ambient temperature during pregnancy and preeclampsia risk.
• To identify critical exposure periods and differentiate risks for early- and late-onset preeclampsia.

Main Methods:

• Utilized a historical cohort of 129,009 pregnancies in southern Israel.
• Merged pregnancy data with temperature data from a hybrid satellite-based exposure model.
• Employed distributed-lag and cause-specific hazard models, stratifying by early (≤34 weeks) and late (>34 weeks) onset preeclampsia.

Main Results:

• A positive association was observed between higher gestational temperatures and increased preeclampsia risk, notably in the third trimester.
• Exposure to 37°C during week 33 was associated with a higher risk (HRCS: 1.07) compared to 22.4°C.
• Associations were found for both early- and late-onset preeclampsia, with stronger effects for early-onset disease during specific critical windows.

Conclusions:

• High ambient temperatures during early and, particularly, late gestation are linked to an elevated risk of preeclampsia in southern Israel.
• Findings highlight the vulnerability of pregnant individuals to heat exposure and inform public health strategies.
• Results underscore the need to consider climate change adaptation in maternal healthcare planning.