As Temperatures Soar, Doctors Warn of Increased Pregnancy Risks

Published August 6, 2026

MADERA, Calif. – As triple-digit temperatures soar and wildfire activity threatens air quality across the Central Valley, experts at Valley Children’s are urging pregnant women to take extra precautions against extreme heat and smoke exposure.

Health experts say pregnancy increases the risk of heat-related illnesses because the body must work harder to regulate temperature while supporting a developing baby. According to the Centers for Disease Control and Prevention, pregnant women are more susceptible to conditions such as heat exhaustion and heat stroke.

“All pregnant patients, even the healthy ones, can develop heat-related illness within an hour of exposure to extreme heat,” said Dr. Daniel Hernandez, medical director for OB/GYN and high-risk delivery service at Valley Children’s Healthcare. “Pregnant people with chronic conditions, like high blood pressure, diabetes or seizure disorders, need to take extra precautions.”

Medical experts also warn that prolonged exposure to extreme heat can increase the risk of preterm and early-term births, stillbirth and low birth weight. Poor air quality from wildfire smoke may further increase health risks by affecting blood flow through the placenta.

To reduce the risk of heat-related illness, experts recommend that pregnant women stay hydrated, limit outdoor activities during the hottest hours of the day, wear lightweight clothing and spend time in air-conditioned environments when possible.

Pregnant women should contact their health care provider if they experience decreased fetal movement, difficulty breathing, signs of dehydration, dizziness, confusion or other symptoms of heat-related illness. Heat stroke is considered a medical emergency and requires immediate treatment.

The health effects of extreme heat and unhealthy air quality can continue after birth, particularly for babies born prematurely or at a low birth weight.

“Babies born prematurely face a higher risk of complications because they are weaker and more vulnerable to severe conditions that can disrupt bodily functions,’ said Dr. James Horspool, complex care pediatrician and medical director of the Charlie Mitchell Children’s Center at Valley Children’s. “However, all infants are vulnerable to excessive heat because they naturally retain more heat than older children and adults, making it harder for them to cool down and stay hydrated.”

Parents are encouraged to watch for signs of dehydration in infants, including fewer than five to seven wet diapers within a 24-hour period. Medical attention should be sought if a baby becomes unusually lethargic, difficult to wake or is feeding poorly.

Wildfire smoke presents another concern for young children, Dr. Horspool said.

“Wildfire smoke is also a significant risk to young babies,” Dr. Horspool said. “The particulate matter in the smoke is very irritating to the delicate tissues inside the lungs. If there is a wildfire near your home, look for resources to help you remove your children from immediate or proximate exposure.”