The Shocking Way Your Flu-Like Symptoms Can Affect Your Baby

A new study aims to uncover how mom's sick days relate to baby's cognitive development. 

Flu-Like Symptoms in Pregnancy Pikselstock/Shutterstock

You might think that minor flu-like symptoms (Think: a slight headache, a bit of fatigue, some achiness) won't affect your pregnancy too much...but if recent research is any indication, those symptoms could leave their mark long after they've faded. 

A team of researchers from the University of Southern California looked at the ways in which the immune systems of pregnant mice reacted to a chemical that mimics a flu-like viral infection. Here's what happened: Levels of tryptophan, which is an amino acid that activates the immune system, went up—this in turn caused the placenta to produce more serotonin, which produced higher quantities of serotonin in the fetal brain.

It sounds harmless enough. After all, in the words of the study's senior author, Alexandre Bonnin, "Serotonin is very important for fetal brain development and can modulate the way the fetal brain is wired." 

But there can be too much of a good thing, at least where serotonin in the brain is concerned. "In response to boosted serotonin levels coming from the placenta, the fetal brain stunted its own genesis of serotonin neurons, probably because receptors sensed there was too much serotonin in there," Bonnin said in a release for the study. "That can be a problem, especially when it leads to the front of the brain not being as developed as it should be."

The study aimed to identify how and why even mild immune attacks (like the flu) alter a baby's central nervous system. Previous studies have linked such attacks during pregnancy to autism, cognitive delay and schizophrenia in offspring.

Does this mean that if you come down with the flu during pregnancy you'll automatically put your child at risk for a central nervous system malfunction? No. According to Bonnin, "Viral infections and inflammation during pregnancy do not guarantee central nervous system malfunctions in children."

"In the first trimester of pregnancy, if the mom gets an infection such as the flu, the risk of the baby developing schizophrenia 15 years later is increased by approximately threefold," Bonnin said. "It doesn't mean that if the mom has the flu, the kid will systematically have schizophrenia, but the risk is increased by threefold."