Extreme heat increasing pregnancy complications, survey shows

Extreme heat has led to a marked increase in the risks faced by pregnant women and their babies, according to a survey of 1,000 health care professionals in countries including Brazil, India and Zimbabwe.

The survey, commissioned by the medical research foundation Wellcome, found that 73% of maternal health care professionals had seen an increase in heat-related complications in the past five years. More than three-quarters reported an increase in harm to fetuses or newborn babies over the same period.

The findings, which also include Australia and the U.K., add to a wealth of scientific evidence linking extreme heat with poor pregnancy outcomes, including maternal deaths and preterm births.

Nearly every health professional who responded said they had cared for a pregnant woman or baby whose health was affected by extreme heat.

The findings were released on Monday (Oct. 5) at a pre-COP summit in Fiji, where Wellcome launched a global call to action on heat and women’s health, ahead of the U.N. climate summit COP31 in Antalya, Turkey, in November.

‘Invisible killer’

Julia Gillard, chair of Wellcome and former prime minister of Australia, said no woman should have to fear that extreme heat will harm her baby.

“Extreme heat is an invisible killer, but pregnant women must not be invisible,” she said. “Leaders have the evidence and solutions they need—now they must act.”

Around a quarter of the survey respondents had seen pregnancy complications that they believed were linked to extreme heat and needed monitoring or treatment.

More than a third also reported low birth weight or restricted growth, dehydration and heat-related illness in newborns. Difficulties in feeding, breathing and temperature regulation were also common.

More than 90% wanted more training and resources to protect pregnant women during extreme temperatures.

Wellcome is calling on governments to prioritize pregnant women and their babies in national climate plans, with specific funded measures to protect them from extreme heat.

The charity has invested more than £20 million in research to understand the risks of extreme heat during pregnancy and test local solutions.

Low-cost solutions

Fortunate Machingura, Zimbabwe country director at the Wellcome Consortiums, leads research for HAPI Zimbabwe, a study looking at how measures designed with local communities can reduce heat risks such as dehydration during labor, preterm birth and heat strain. The study is working with 1,600 women in urban South Africa and rural Zimbabwe.

Low-cost measures being tested include a heat alert system that provides personalized smartphone warnings, relayed by community health workers to women without phones; cooling kits that support hydration and sun protection; and reflective roofs to cool buildings.

Other interventions are even simpler: families share demanding tasks and schedule work for cooler hours, while male “heat champions” help fetch and store water.

For Machingura, these measures make it possible to protect pregnant women from the worst effects of heat.

“Advice means little if water is kilometers away,” she told SciDev.Net. “HAPI engages families, women’s groups, chiefs and maternity services, asking men to share responsibilities women often carry alone.”

Demanding work, water insecurity and heat-retaining buildings add to the heat stress for women in the northeastern Mount Darwin district, home to the country’s first Climate Health Demonstration Laboratory, says Machingura.

She says early findings from the study here showed significantly lower levels of dehydration among women who received the HAPI intervention compared with those who did not.

Record heat

The findings come as the European Earth observation program Copernicus declared August the joint warmest month ever recorded, tied with July 2023. They also come amid an intensifying El Niño event, which is affecting temperature patterns.

India has experienced acute heat waves this year, with temperatures exceeding 45°C (113°F) in some regions.

Neelam Singh is chief functionary of the Indian nonprofit Vatsalya, which works to improve the health and well-being of women and girls, particularly in India’s Uttar Pradesh. She says the survey findings reflect the heat-related health challenges Vatsalya is seeing on the ground for women during pregnancy and after childbirth.

“In particular, excessive heat can contribute to dehydration and physical exhaustion during pregnancy, while also potentially affecting fetal well-being and newborn health,” Singh told SciDev.Net.

“We have also observed that heat and associated dehydration adversely affect women during the postpartum period, including their ability to initiate and sustain adequate lactation,” she said, adding that data to quantify this is currently lacking.

Previous studies, however, have shown a clear link between heat and adverse pregnancy outcomes. A study published in the journal Environment International concluded that 1.4% of premature births can be attributed to heat during the warm season—equivalent to 855 cases per million births. The study featured by SciDev.Net’s Latin America and Caribbean edition analyzed data from 13 countries over a 40-year period.

Climate ‘fault line’

Speaking at a ministerial meeting organized by Wellcome in Fiji on Monday (Oct. 5), Simon Stiell, head of the United Nations Framework Convention on Climate Change, said extreme heat was making pregnancy the “new fault line” of the climate crisis.

Reflecting on the survey data, he said, “Behind those numbers are human stories: an expectant mother’s journey to a clinic delayed by dangerous heat; a midwife working through unsafe temperatures; a newborn needing specialist care.”

He added, “A safe birth is already too often shaped by geography, income and access to care. Without action, extreme heat will widen that injustice.”

Provided by
SciDev.Net

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Lisa Lock

BA art history, MA material culture. Former museum editor, paramedic, and transplant coordinator. Editing for Science X since 2021.

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Andrew Zinin

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