Higher Sun Exposure in the First Trimester Is Associated With Reduced Preterm Birth; A Scottish Population Cohort...

Area of Science:

• Obstetrics and Gynecology
• Environmental Health
• Perinatal Epidemiology

Background:

• Preterm birth (<37 weeks gestation) is a leading cause of under-5 mortality globally.
• Prevention strategies for preterm birth are a critical public health priority.
• The impact of environmental factors like sun exposure on pregnancy duration remains largely unexplored.

Purpose of the Study:

• To investigate the association between available sunlight exposure and the risk of preterm birth.
• To explore potential dose-response relationships and subgroup variations.

Main Methods:

• Population-based data-linkage study in Scotland (2000-2010) involving 556,376 singleton births.
• Maternity records linked to meteorological sunshine data by postcode.
• Logistic regression analyses, including sibling analyses and subgroup analyses for spontaneous and indicated preterm births.

Main Results:

• Higher available sun exposure in the first trimester of pregnancy was significantly associated with a reduced risk of preterm birth.
• A dose-response relationship was observed, with the highest quartile of sun exposure showing a reduced odds ratio (OR) of 0.91 (95% CI 0.87-0.93).
• No significant association was found with second-trimester or combined first- and second-trimester sun exposure.

Conclusions:

• First-trimester sun exposure demonstrates a protective effect against preterm birth.
• This finding highlights novel mechanisms and potential therapeutic avenues for preterm birth prevention.