Heat waves hazardous for women.- edited by Aishee Biswas

Climate change is causing extreme temperatures, droughts, famines, and increased precipitation in many countries around the world. The Lancet has reported that climate change is the largest threat to global public health in the 21st century. The report from July 2021 also revealed that over five million people die on average each year worldwide due to extreme temperatures in a span of two decades (2000-2019). Climate change is causing an increase in death and illness due to severe weather, worsening air quality, changing patterns of infection, and disruption to food supplies. In addition, the Indian Meteorological Department reported that February of this year was the hottest on record since 1901.

Given the proven detrimental effects of extreme climatic conditions on health, the question arises as to how pregnant women in developing countries are affected by these conditions, particularly heatwaves.

Until the final days of pregnancy, many women engage in physical labor. However, climate change is exacerbating their susceptibility to spontaneous abortions, premature labor, and low birth weight, resulting in higher rates of neonatal morbidity and mortality. Expecting mothers in India are exposed to dehydration, vector-borne diseases like malaria and dengue, and extreme temperatures and precipitation, which are endemic in the region. The risk of diarrhea leading to dehydration, exhaustion, fetal malnutrition, and worm infestation increases due to climate change, which can further lead to anemia, said many doctors.

According to a study,  climate change is expected to raise the occurrence of vector-borne illnesses such as malaria , dengue fever, and Zika virus, which can have significant adverse effects on pregnant women and fetuses.

Maternal and child health are among the most affected areas by climate-sensitive diseases in India, which has been found to have the highest burden of such diseases in the world, as per a 2018 study by the National Center for Biotechnology Information.

Dehydration during pregnancy can have several negative effects on both the mother and the developing fetus. One of these effects is the lowering of amniotic fluid, which serves as a protective cushion against physical impact and temperature changes, and also allows the baby to move freely for proper growth and development.

Dehydration can also increase the frequency of urinary tract infections due to urinary concentration. Additionally, exposure to high temperatures that cause severe dehydration can lead to low blood pressure, resulting in fatigue, dizziness, and even fainting.

Premature labor: Elevated temperatures can cause the secretion of anti-diuretic hormones and oxytocin which can retain water in the body. This release of oxytocin may trigger early contractions that can lead to preterm labor.

Decreased fetal growth: High temperatures can reduce the blood flow to the uterus and, in turn, to the fetus. This may result in a lack of nutrition and oxygenation for the baby, leading to suboptimal fetal growth known as intrauterine growth retardation.

Increased risk of preeclampsia: Exposure to high temperatures can cause inflammation and oxidative stress in the body, increasing the risk of high blood pressure conditions such as preeclampsia in women who are already prone to hypertension.

Higher incidence of birth defects: Prolonged exposure to high temperatures, particularly during the first trimester, can increase the likelihood of birth defects such as neural tube defects and congenital heart defects.