Pregnant Women Face Growing Heat Risks in Hong Kong as Climate Change Outpaces Maternal Health Advice

By: Oluwaseun M Lawal

For many expectant mothers in Hong Kong, summer has become more than just uncomfortable. It has quietly turned into something they never imagined could threaten their pregnancies. The heat arrives early. It stays longer. Nights no longer bring much relief. Yet inside many antenatal clinics across the city, conversations about extreme temperatures are still largely missing.

That silence worries public health experts.

Siti, a 37-year-old woman who is six months pregnant, knows what it feels like to live through Hong Kong’s punishing summer. She spends most days inside her tiny sixth-floor apartment in Sham Shui Po, keeping her air conditioner running almost constantly. On particularly hot days, she takes several cold showers just to feel normal again.

She has attended regular prenatal appointments at Kwong Wah Hospital. But despite those visits, nobody ever explained that excessive heat itself could put both her and her unborn child at risk.

“I didn’t know,” she said.

Her experience appears far from unique.

A survey involving 29 pregnant and recently pregnant women in Hong Kong found that only three had ever received advice about heat exposure from a healthcare professional. Even then, the guidance mostly focused on drinking enough water and staying indoors. None recalled being warned that prolonged exposure to extreme heat has been linked in scientific studies to miscarriage, premature birth or stillbirth.

For many women, that information simply never came.

Yet many of them were already experiencing the effects.

Twenty-six respondents said the hot weather had made their pregnancies more difficult. Some described constant exhaustion. Others reported dizziness, swollen feet, rapid heartbeat, dehydration and even fainting while carrying out everyday activities. One woman said she collapsed twice while walking to catch a bus during her first trimester. Another admitted she repeatedly felt as though she was about to suffer heat stroke.

Small moments. But frightening ones.

Medical research increasingly suggests these experiences should not be dismissed as ordinary discomfort.

A large review of international studies published in 2020 found that heatwaves can significantly increase the likelihood of preterm birth. Other peer-reviewed research has associated high temperatures during pregnancy with miscarriage, low birth weight, birth defects, hypertension during pregnancy and stillbirth.

Scientists say the problem becomes even more serious as climate change pushes temperatures higher across Asia.

Hong Kong itself has witnessed dramatic changes over the last century. Very hot nights have become far more common, while extremely hot days are now recorded much more frequently than in previous decades. Combined with the city’s notorious humidity, conditions can quickly become dangerous for vulnerable groups.

Professor David Bishai of the University of Hong Kong’s School of Public Health believes pregnant women have largely been overlooked in climate adaptation efforts.

According to him, they represent one of the missing populations when governments discuss protection from extreme heat.

Doctors working directly with expectant mothers share similar concerns.

Professor Wing-Hung Tam, an honorary clinical professor in obstetrics and gynecology at the Chinese University of Hong Kong, said medical training traditionally warns women against activities like using hot springs or saunas during pregnancy. However, he noted that discussions rarely extend to prolonged exposure to hot outdoor temperatures.

That gap matters because elevated body temperature during pregnancy may affect fetal development, particularly during the early stages.

Dr. Zara Chan, an obstetrician and gynecologist in private practice, routinely discusses heat risks with her patients. She encourages them to remain hydrated, seek cool environments and pay close attention to warning signs such as dizziness, fainting and dehydration.

But she admits that such conversations are far less common in the public healthcare system.

Many women therefore leave hospital appointments with advice covering nutrition, exercise, sleep and smoking, yet receive little or no information about coping safely with increasingly intense heat.

Public health advocates say this needs to change.

Hong Kong’s Department of Health already recognizes pregnant women as a vulnerable group during periods of extreme weather and regularly issues general heat advisories encouraging hydration and staying cool. However, pregnancy-specific guidance explaining the possible effects of prolonged heat exposure has not become part of routine prenatal education.

Several organizations argue that awareness alone is not enough.

Women working outdoors may face even greater risks. Construction workers, surveyors, cleaners and domestic workers often continue working in high temperatures, especially during the early months of pregnancy before informing employers about their condition.

Current workplace heat guidance in Hong Kong remains largely voluntary, offering recommendations such as rest breaks rather than enforceable protections specifically designed for pregnant employees.

Health experts believe stronger policies are needed alongside better education.

Around the world, some countries have begun introducing pregnancy-focused heat awareness initiatives. Researchers from several nations are also developing digital tools capable of warning pregnant women whenever dangerous temperatures are forecast while providing practical advice to reduce health risks.

Professional medical organizations are also paying closer attention. The American College of Obstetricians and Gynecologists recently acknowledged the growing evidence connecting climate-related hazards—including extreme heat—to pregnancy complications such as preterm birth, stillbirth and pregnancy loss.

For frontline healthcare workers in Hong Kong, the solution could begin with something surprisingly simple.

Ask every pregnant woman whether she has access to cooling at home. Explain the risks during prenatal appointments. Help families create practical plans before the hottest months arrive.

For Siti, that kind of conversation would have made a difference.

Instead, she continues relying on her instincts, keeping the air conditioner running despite rising electricity bills and limiting trips outside whenever possible.

Looking back, she says she wishes someone had simply told her earlier.

Sometimes the most important medical advice doesn’t require expensive technology or complicated treatment. Sometimes, it starts with a conversation before the heat arrives.