What are the effects of campfire smoke exposure during pregnancy?

From the Guidelines

Pregnant women should avoid exposure to campfire smoke as much as possible to minimize the risk of low birth weight, preterm birth, and pregnancy loss, as well as potential long-term respiratory issues in children. The evidence suggests that landscape fire smoke exposure during pregnancy is associated with adverse perinatal outcomes, including low birth weight, preterm birth, and pregnancy loss 1. Campfire smoke contains harmful chemicals, such as particulate matter, carbon monoxide, and polycyclic aromatic hydrocarbons, which can cross the placenta and potentially affect fetal development 1.

Some key points to consider:

• The gestational period has several unique challenges for exposure analysis, including varying gestational lengths and the concept of 'minoris resistentiae', or critical period of susceptibility 1.
• The discovery of black carbon particles resulting from combustion found on the fetal side of the human placenta, in the fetal liver, lung, and brain, provides evidence for the possible 'insult' of landscape fire smoke on the developing fetus 1.
• Mechanistic work from air pollution and environmental tobacco smoke studies suggests that in utero PM2.5 exposure causes epigenetic and neonatal immune changes in the fetus, resulting in adverse perinatal and respiratory outcomes 1.

If exposure to campfire smoke is unavoidable, pregnant women should:

• Minimize time spent near the fire
• Position themselves upwind of the smoke
• Ensure the campfire area is well-ventilated
• Wear a mask if necessary
• Move to fresh air immediately if symptoms like coughing, wheezing, or difficulty breathing occur, and contact their healthcare provider. While enjoying outdoor activities during pregnancy is beneficial, taking precautions around campfires helps protect both maternal and fetal health.

From the Research

Effects of Campfire Smoke Exposure During Pregnancy

• Campfire smoke exposure during pregnancy can lead to adverse obstetric outcomes, including inflammation, oxidative stress, endocrine disruption, DNA damage, telomere shortening, epigenetic changes, as well as metabolic, vascular, and endothelial dysregulation in the maternal-fetal unit 2.
• Exposure to air pollution and other combustion sources, such as tobacco and diesel, has been linked to similar adverse outcomes, suggesting a potential risk from campfire smoke exposure 2, 3, 4.
• Strategies to reduce exposure to campfire smoke, such as limiting time outdoors, wearing N95 respirator face masks, and using high-quality indoor air filters, may help mitigate the risks 2.

Comparison to Other Forms of Smoke Exposure

• Secondhand smoke exposure during pregnancy has been associated with low birth weight, preterm birth, and delayed infant neurodevelopment 5, 3, 4.
• Tobacco smoke exposure during pregnancy has been linked to an increased risk of obstetric complications and adverse health outcomes for children exposed in-utero 3.
• Environmental exposure to contaminants, including air pollutants, during pregnancy has been associated with preterm birth, fetal growth restriction, and other negative birth outcomes 4.

Management and Prevention

• Reducing exposure to campfire smoke and other environmental contaminants is crucial to preventing adverse obstetric outcomes 2, 4.
• Counselling interventions and nicotine replacement therapy have been shown to be effective in helping pregnant women quit smoking and reduce their exposure to tobacco smoke 3.
• Further research is needed to fully understand the effects of campfire smoke exposure during pregnancy and to develop effective strategies for prevention and management 2, 3, 4.