Pregnant Womens Bodies Could Make Flu Evolve IntoSuperflu

I can’t imagine much worse than having the flu while you’re pregnant. I mean, the first trimester feels like one long flu anyways. Add fever and a threat to baby’s health? Too much.

To pile on the already unfortunate situation, your body may actually be making the flu worse for everyone else as well. A recent study found that a pregnant woman’s body might be making the flu virus mutate into a more savage version of itself. The study was carried out in mice, but the researchers still found the most common form of the flu present after contact with pregnant mice was the most nasty one. It’s a superbug factory.

The flu virus is already a master mutator. That’s why we need a new vaccination every year. But, in a pregnant women whose immune systems are down, it has the opportunity to change much more.

That’s just how MRSA, a particularly nasty superbug, is evolving . Hospital patients with weak immune systems catch the bacteria, but their bodies can’t kill all of it. The bacteria then have ample opportunity to change and develop defenses against the hosts immune cells. After thousands of patients and thousands of different immune systems, the bacteria became really good at it. Hence, superbug status.

A pregnant woman’s immune system is hindered, too, but for a different reason. Baby is like a foreign organism — its got its own DNA and blood type, after all. The placenta helps mediate the foreign-ness by filtering back and forth between mother and child, but in the end, the immune system still has to operate at lower levels anyway.

Lowered immune system means higher susceptibility to disease and more time to let the virus adapt. It’s the perfect disease vector, really. But, god is it demoralizing to think that while we’re prepping for baby and trying to get comfortable, the flu could be inside us, busy making next year’s batch. The take-home message? Get your flu shot, gals.

Casey Rentz is a science writer whose essays have appeared in New Scientist, Scientific American, Smithsonian.com, The Guardian, and Best Science Writing Online book series. She lives in Los Angeles with her husband and two kiddos. Find her at www.caseyrentz.com. Follow her at Facebook , Twitter .

*First published at The Nest: Finding Nature in Parenthood