Singapore’s tropical heat can feel relentless, especially for expectant mums. Pregnancy itself raises core body temperature and causes physiological changes that make cooling less efficient. Dr Harvard Lin, Consultant Obstetrician, Gynaecologist, and Urogynaecologist at AOGC, explains the heightened vulnerabilities and bullet‑proof strategies to stay safe in the sun.
Why Pregnant Women Are More Vulnerable to Heat‑Related Illnesses
Pregnancy brings about hormonal shifts and increased metabolic rate. Dr Lin says that “most women experience an increase in body temperature during pregnancy … making them more sensitive to high temperatures, and at higher risk of heat‑related illnesses.”
This is due to:
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↑ Blood volume & heart rate (up to +20% cardiac output by week 8)
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Progesterone-induced vasodilation
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Excess body mass and fat
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High humidity in Singapore, reducing sweat evaporation and efficient cooling
Heat‑Related Complications Pregnant Women May Face
While feeling warm is normal during pregnancy, prolonged exposure to high heat can lead to serious health problems. Dr Lin explains the common heat-related complications that expectant mothers should watch out for.
Hot and humid weather causes the body to lose fluids and salts faster through sweat. Severe dehydration can be dangerous for both mother and baby, as it may reduce amniotic fluid levels and affect nutrient transport to the foetus.
Nutrient Deficiencies Caused by Dehydration
When fluid loss isn’t replaced, essential nutrients like calcium, magnesium, and potassium can drop, affecting the baby’s growth and development.
Fatigue
Dr Lin notes, “Extreme exhaustion or lack of energy is normal in pregnancy; and hot weather can further intensify this feeling.” Persistent overheating may strain the cardiovascular system, indirectly limiting oxygen delivery to the baby.
Heat Exhaustion
The body works harder to cool both mother and baby. Symptoms such as dizziness, excessive sweating, and weakness should be treated immediately to prevent escalation.
Heat Stroke – The Most Serious Risk
Dr Lin warns, “Heat stroke is dangerous for both the mother and their unborn foetus and may lead to brain, heart, kidney and muscle damage.” Prolonged heat stroke can even increase the risk of stillbirth.
How High Heat Exposure Affects the Baby
Neural Tube Defects (Spina Bifida, Anencephaly)
High maternal temperatures in the first trimester increase the risk of neural tube defects. “These defects occur when the neural tube, which later forms the brain and spinal cord, fails to close properly,” says Dr Lin.
Congenital Heart Defects
Heat stress in early pregnancy can interfere with heart development, leading to structural abnormalities at birth.
Preterm Birth
Persistent heat exposure raises the likelihood of early labour, which can lead to respiratory issues, developmental delays, and long-term health problems.
Stillbirth
Dr Lin warns that “severe heat exposure has been linked to an increased risk of stillbirth, where the foetus dies in the womb after 20 weeks of pregnancy.”
Placental Insufficiency
Heat stress can impair placental function, “reducing the supply of oxygen and nutrients to the foetus, potentially leading to growth and developmental issues,” according to Dr Lin.
Babies exposed to continuous heat stress during pregnancy are more likely to be born underweight, making them vulnerable to infections and chronic health conditions later in life.
When to Seek Medical Help
While mild heat discomfort is common, seek medical attention immediately if you experience any of the following symptoms:
Dr Lin emphasises that palpitations, breathlessness when lying down, or any sign of cardiovascular compromise require urgent medical care.
Diet Tips for Expectant Mums in Hot Weather
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Stay hydrated: Carry a bottle of water everywhere; drink frequently, even if you’re not thirsty.
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Avoid dehydration triggers: Minimise caffeine, sugary drinks, and salty foods.
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Eat smaller, frequent meals: Heavy meals can increase body heat.
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Choose nutrient-rich foods: Green leafy vegetables, whole grains, fish, chicken, eggs, and vitamin C-rich foods (tomatoes, capsicum).
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Opt for cooling fruits: Watermelon, papaya, and cucumber help maintain hydration.
Lifestyle Tips to Beat the Heat While Pregnant
If you’re looking for ways to stay cool while carrying your baby, follow Dr Lin’s practical tips:
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“Rest or take a nap when you can in a cool, darkened room.”
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“Invest in a cooling leg gel and take regular breaks to sit with your feet up in front of a fan or in an air‑conditioned room.”
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“Place a bowl of ice cubes in front of an electric fan for a cooling breeze.”
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“Have a spray bottle filled with water to cool your face and body.”
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“Place a wet towel on your head or neck, or fill a bowl with cold water to put your feet in.”
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“A lukewarm shower or bath can help during the day. At night it can be soothing and may help you get a more restful night’s sleep.”
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“If you have another child, sitting with your feet in the water of a shaded paddling pool is a good way to cool down, as well as keeping watch while your child enjoys the water.”
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“Avoid going out in the hottest part of the day, usually mid to late afternoon. Limit trips or shopping when temperatures are at their highest.”
Final Advice from Dr Harvard Lin
Dr Lin’s advice is simple but crucial:
“Be mindful of your surroundings and listen to what your body is telling you.”
He stresses that heat-related illnesses are preventable if mums-to-be stay cool, rest frequently, keep hydrated, and seek medical help early when feeling unwell.
About Dr. Harvard Lin
Dr. Harvard Lin is a Consultant Obstetrician, Gynaecologist, and Urogynaecologist at the Asian Obstetrics & Gynaecology Centre (AOGC) in Singapore. With dual accreditation in both general obstetrics and urogynaecology, Dr. Lin combines clinical excellence with compassionate care to support women through all stages of life. He is a Fellow of the Royal College of Obstetricians and Gynaecologists (UK) and the Academy of Medicine, Singapore, with a strong commitment to high-risk pregnancy care, pelvic floor disorders, and minimally invasive surgery.
