JUL 17, 2022 7:09 PM PDT

Increased Risk of Miscarriage in Summer Heat

WRITTEN BY: Alexandria Bass

Extreme summer heat is miserable for all of us, but new research is finding it may be especially dangerous for pregnant women who face an increased risk of miscarriage during peak summer months.

A research team led by Amelia Wesselink, PhD, assistant professor of epidemiology at Boston University School of Public Health, found that pregnant women have a 44% higher risk of miscarriage in August than in February, the month with the lowest rate of miscarriage. Heat is thought to be behind this finding, but researchers plan to dig deeper into potential causes. 

In their study, Wesselink and her team analyzed pregnancy outcomes for more than 12,000 women across different seasons. Miscarriage rates were highest in peak summer—late August—especially for women in some of the hottest areas of the country, the southern and midwestern U.S.

Between 2013 and 2020, data were collected on American and Canadian pregnant women enrolled in the Pregnancy Study Online (PRESTO), an internet-based fertility study from Boston University School of Public Health. Each study participant was followed for up to one year after enrollment. Researchers looked at participants’ income, education, race, ethnicity, lifestyle, and responses to follow-up questions about their pregnancy and miscarriage. Women seeking fertility treatments were not included in the study.

Most of the women in the study were white (86%), had at least a college degree (79%), and many earned more than $100,000 a year (47%). Half of the women were able to conceive within a year of planning to get pregnant. Of the women who did conceive, nearly 20% of them miscarried.

The risk of miscarriage was 44% higher in August for pregnancies in their first 8 weeks and 31% higher for pregnancies at any point.

Saifuddin Ahmed, PhD, a researcher at Johns Hopkins Bloomberg School of Public Health in Baltimore, stated extreme heat may not be the only thing to blame for this observation. “You need to be careful when linking summer months to miscarriage, as women may pursue more outdoor activities during summer.”

Wesselink also noted that study participants were not representative of the general population—most were white and wealthier than average.

Sources: EpidemiologyMedscape

About the Author
BA in Psychology
Alexandria (Alex) is a freelance science writer with a passion for educating the public on health issues. Her other professional experience includes working as a speech-language pathologist in health care, a research assistant in a food science laboratory, and an English teaching assistant in Spain. In her spare time, Alex enjoys cycling, lap swimming, jogging, and reading.
You May Also Like
NOV 08, 2022
Technology
People say too much screen time is bad for kids. But is it really the problem?
NOV 08, 2022
People say too much screen time is bad for kids. But is it really the problem?
Screen time is a parent’s conundrum. How much screen time is too much? How do I adequately monitor my child’ ...
NOV 11, 2022
Immunology
Regenerating the Immune System to Halt Multiple Sclerosis
NOV 11, 2022
Regenerating the Immune System to Halt Multiple Sclerosis
A bone marrow or blood stem cell transplant has been an effective but risky way to treat multiple sclerosis (MS), and no ...
NOV 15, 2022
Genetics & Genomics
Revealing the Mutations that Make Melanoma Immortal
NOV 15, 2022
Revealing the Mutations that Make Melanoma Immortal
Telomeres cap the ends of chromosomes, preventing breakage. Some cancer cells can use those protective caps to their adv ...
NOV 17, 2022
Drug Discovery & Development
Implantable Pump Delivers Chemotherapy Directly to the Brain
NOV 17, 2022
Implantable Pump Delivers Chemotherapy Directly to the Brain
An implantable pump can bypass the blood-brain barrier and deliver chemotherapy to specific brain areas. The correspondi ...
NOV 17, 2022
Neuroscience
Fluorescent Proteins Extend Blood Flow Tracking to Months in Mice
NOV 17, 2022
Fluorescent Proteins Extend Blood Flow Tracking to Months in Mice
Harmless, fluorescent proteins allow scientists to track blood flow in mice. The advance could help researchers monitor ...
NOV 18, 2022
Plants & Animals
Cannabis Users Have Worse Bypass Outcomes, Increased Risk of Amputation
NOV 18, 2022
Cannabis Users Have Worse Bypass Outcomes, Increased Risk of Amputation
Lower extremity bypass surgery is a common procedure used to address occluded arteries in the leg, usually with the goal ...
Loading Comments...