It's flu season. If you're exposed to the virus, it could mean fever, muscle aches, cough and a sore throat. That's if you're a healthy adult.  

If you're a child, a senior citizen, or pregnant, you're at much greater risk. For these groups, the flu can be extremely dangerous. If you're pregnant, the best way to protect yourself and your fetus from the flu is the flu vaccine. 

"The chance of being hospitalized, being in the intensive care unit, and dying from influenza are all higher during pregnancy," says Leo Pereira, M.D., M.C.R., perinatologist at OHSU. 

Vaccinated pregnant women who are exposed to the flu will have less serious symptoms or even avoid getting sick altogether. Moreover, the protection is passed on to the fetus. So if your baby is born during flu season, he or she will also be less likely to get sick. 

I heard there might be risks 

You may have seen news stories about a study that suggested an association between the flu vaccine and early-term miscarriage in pregnancy.  

There are plenty of reasons not to worry. At least seven other studies have looked at risks of the flu vaccine in pregnancy, and none of them found an association with miscarriage.  

In addition, there are many differences between the women in the study who had miscarriages and the women in the control group that have nothing to do with the flu vaccine.  

"The patients who miscarried were older, had a higher body-mass index, and were more likely to be smokers," Dr. Pereira says. All of these factors are known to increase the risk of miscarriage. 

"Whenever there's a finding like this, we need to look into it further. It's important to get more data and determine if the findings can be replicated," says Dr. Pereira. "But we don't want to jump the gun and change practice just because one study found an association." 

The bottom line 

Dr. Pereira wants patients to know that it's still very important to get vaccinated as soon as the flu vaccine is available in the fall. "Delaying until the flu season gets bad just increases the chances you'll get sick," he says. "We know that's a very real risk."