Study: Autism Risk Increases 34% if Mother Has Fever While Pregnant

New research published in Molecular Psychiatry reveals that pregnant women who have fever, especially in their second trimester, may have a heightened autism risk for the baby. 

While this is not the first time autism in children has been linked to infections in the mother, this study is believed to be the most comprehensive so far. 

The purpose of this research was to examine if high temperatures in pregnancy were connected to autism in the child years later, and if by lowering the fever with medication, this outcome could be influenced or changed. 

Autism risk during pregnancy: The study

A team of researchers from Columbia University’s Mailman School of Public Health observed 95,754 Norwegian children born between 1999-2009.

During this time, around 15,700 babies were born to mothers who had fever while pregnant. Within than group, over 580 cases of autism spectrum disorder among children were identified. 

What's more, after adjusting for factors such as maternal age, smoking status and previous pregnancies, if the mothers had a slight fever at any time in their pregnancy, autism risk increased by 34%.

The risk increased to 40% when fever was reported in the second trimester of pregnancy, in comparison to children whose mothers were fever-free. 

Women who had fever three or four times after 12 weeks of pregnancy had increased autism risk for their child by more than 300%. 

No need to panic!

Now all this information might be scary if you are currently pregnant and reading this article. This is where we need to tell you that the overall risk is still very low, as pointed out by the lead researcher of the study Dr. Mady Hornig, who is associate professor of epidemiology at Columbia University’s Center for Infection and Immunity.

To break it down even further for you: Even among the mums who had several bouts of fever after 12 weeks gestation, only 5 out of 308 kids developed autism. 

What's the link between fever and autism?

As you know, fever is the body's showing you that it's battling an infection. It's a perfectly normal sign of a healthy immune system. 

Experts still don't know the exact reasons for an infection to increase the chances of autism in the child.

However, Dr. Hornig has a theory. She explains that the second trimester is  crucial for brain development in the baby. And during this time, mummy's immunity is lowered so the developing baby won't be rejected by her body. 

Together, "these factors could make her offspring more vulnerable to developmental disruption," says Dr. Hornig. 

As a follow-up to this study, researchers are now looking at blood samples from both the mums and their children. This will allow them to find out if certain infections (or immune reactions from the mother) are associated with a higher risk of autism. 

Interestingly, those mums who took ibuprofen to bring down the fever during pregnancy had autism-free children. But Dr. Hornig says "this finding should be interpreted with "extreme caution", and certainly warrants further investigation. 

Simple health precautions while pregnant

Mums-to-be, you can lower the risk of developing an infection by following a few basic rules, such as: 

• Eating healthily 
• Washing your hands often
• Avoiding crowded places and association with sick people

Consult your doctor about getting the flu shot to protect yourself and your baby after his or her birth. 

Please seek the opinion of your doctor if you have any health concerns during pregnancy.