Heat stress and fetal risk. Environmental limits for exercise and passive heat stress during pregnancy: a systematic review with best evidence synthesis
Ravanelli N, Casasola W, English T, Edwards KM, Jay O
British journal of sports medicine · 53 citations
How it was studied
- Design
- Systematic review (indexed by PubMed)
- Studied in
- People
- Main outcome
- Health markers and function
Who paid for it
- Funding
- Independent funding
- University or hospital
- University of Ottawa
- Government
- Bộ Giáo dục và Ðào tạo
Based on 2 listed funder(s).
Publication
- Published
- 2018-03-01 · Br J Sports Med · vol. 53 · issue 13 · pp. 799–805
- Publisher
- BMJ
- Cited
- 96 citations · more than 70% of similar papers · 0.9× the field average
- References
- 83 works
- Access
- Paywalled
- Research areas
- Thermoregulation and physiological responses · Gestational Diabetes Research and Management · Cancer Risks and Factors
- Keywords
- Medicine, CINAHL, Pregnancy, Hyperthermia, Heat stress, Meta-analysis, Gestation, Core (optical fiber), Physical therapy, Obstetrics, Internal medicine, Psychological intervention, Animal science
- MeSH
- humans, heat stress disorders, body temperature, treatment outcome, exercise, body temperature regulation, heat-shock response, pregnancy, female, teratogenesis
5 authors
From AU, CA, GB
- Nicholas RavanelliThe University of Sydney; University of Ottawa
- William CasasolaThe University of Sydney; University of Exeter
- Timothy EnglishThe University of Sydney
- Kate M. EdwardsThe University of Sydney
- Ollie Jay · correspondingThe University of Sydney; University of Ottawa
Abstract
Objective
Pregnant women are advised to avoid heat stress (eg, excessive exercise and/or heat exposure) due to the risk of teratogenicity associated with maternal hyperthermia; defined as a core temperature (Tcore) ≥39.0°C. However, guidelines are ambiguous in terms of critical combinations of climate and activity to avoid and may therefore unnecessarily discourage physical activity during pregnancy. Thus, the primary aim was to assess Tcore elevations with different characteristics defining exercise and passive heat stress (intensity, mode, ambient conditions, duration) during pregnancy relative to the critical maternal Tcore of ≥39.0°C.
Design
Systematic review with best evidence synthesis.
Data sources
EMBASE, MEDLINE, SCOPUS, CINAHL and Web of Science were searched from inception to 12 July 2017.
Study eligibility criteria
Studies reporting the Tcore response of pregnant women, at any period of gestation, to exercise or passive heat stress, were included.
Results
12 studies satisfied our inclusion criteria (n=347). No woman exceeded a Tcore of 39.0°C. The highest Tcore was 38.9°C, reported during land-based exercise. The highest mean end-trial Tcore was 38.3°C (95% CI 37.7°C to 38.9°C) for land-based exercise, 37.5°C (95% CI 37.3°C to 37.7°C) for water immersion exercise, 36.9°C (95% CI 36.8°C to 37.0°C) for hot water bathing and 37.6°C (95% CI 37.5°C to 37.7°C) for sauna exposure.
Conclusion
The highest individual core temperature reported was 38.9°C. Immediately after exercise (either land based or water immersion), the highest mean core temperature was 38.3°C; 0.7°C below the proposed teratogenic threshold. Pregnant women can safely engage in: (1) exercise for up to 35 min at 80%-90% of their maximum heart rate in 25°C and 45% relative humidity (RH); (2) water immersion (≤33.4°C) exercise for up to 45 min; and (3) sitting in hot baths (40°C) or hot/dry saunas (70°C; 15% RH) for up to 20 min, irrespective of pregnancy stage, without reaching a core temperature exceeding the teratogenic threshold.
Abstract via Europe PMC. Copyright remains with the authors or publisher.
Community trust
Loading…
How much do you trust this study's findings?
Comments
Sign in to rate, comment on or flag this study.Sign inSomething wrong here?
Flag this study if its information, labels or funding look wrong. An editor reviews every flag.
Sign in to rate, comment on or flag this study.Sign inEducational information about published research. Not medical advice, and not a recommendation to start or stop anything.