ArticleBJOG : an international journal of obstetrics and gynaecology2026
Heat Stress and Placental Abruption: A Space-Time Stratified Case-Crossover Study.
Article in BJOG : an international journal of obstetrics and gynaecology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers, 1 of them a synthesis that pooled it.
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Who cites it
3 citing papers in PubMed, 1 synthesis or guideline pooled it.
- A systematic review and meta-analysis on heat thresholds for maternal health and birth outcomes.Nature communications · 2026Pooled it
- Heat Stress and Placental Abruption: A Space-Time Stratified Case-Crossover Study.BJOG : an international journal of obstetrics and gynaecology · 2026Article
- Reduction of stillbirth rate in refugee and migrant populations living on the Thailand Myanmar border: A retrospective study 1986-2023.PLOS global public health · 2026Article
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4 authors.
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Abstract
objectiveTo examine whether heat stress, measured by wet bulb globe temperature (WBGT), a comprehensive heat stress index is associated with placental abruption within 7 days.
designA space-time-stratified case-crossover design.
settingAll 11 regions in Japan during the warm season (June-September) from 2011 to 2020. POPULATION: 6947 cases of placental abruption were registered in the Japan Perinatal Registry Network database.
methodsQuasi-Poisson regression with distributed lag linear models assessed the association between heat stress, defined as daily maximum WBGT exceeding the 95th percentile of the regional distribution during the warm season, and daily placental abruption cases over a lag period of 0-7 days. Stratified analyses examined gestational week (preterm vs. term), hypertensive disorders of pregnancy (HDP), and small for gestational age (SGA).
main outcome measuresClinical diagnosed placental abruption.
resultsHeat stress was associated with an increased risk of placental abruption on lag 1 (relative risk [RR]: 1.23, 95% confidence interval [CI]: 1.11-1.39) and lower risk on lag 2 (RR: 0.84, 95% CI: 0.74-0.95), with negligible cumulative risk over lag 0-7 due to counterbalancing effects. Similar patterns were observed in preterm and term pregnancies. Individuals with HDP showed a higher risk on lag 1 (RR: 1.57, 95% CI: 1.31-1.88), as did those with SGA infants (RR: 1.47, 95% CI: 1.26-1.73).
conclusionsHeat stress during pregnancy may increase the risk of placental abruption on the day after exposure, potentially advancing cases that might have occurred later, particularly in individuals with HDP or SGA infants.
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