Flu vaccine does not carry miscarriage risks, experts say

According to several studies presented as the 49th annual meeting of the Infectious Disease Society of America's Pandemic Influenza Task Force, the flu vaccine does not raise the risk of miscarriage in pregnant women.

The studies also showed that the vaccine protects newborn infants for four months and that pregnant mothers are getting the message about both the flu shot's importance and its safety, Medical News Today reports.

"Pregnant women are understandably concerned about protecting their unborn babies, which makes it all the more important for them to understand that getting a flu shot during pregnancy is an important way to protect the baby, as well as themselves," Dr. Kathleen Neuzil, a member of the task force, said, according to Medical News Today. "These new data on the safety and effectiveness of these vaccines is reassuring, and the increasing number of pregnant women receiving the vaccine affirms that women are hearing the message about the vaccine's benefits."

Researchers from Wisconsin's Marshfield Clinic compared 243 pregnant women who had a miscarriage with 243 women who didn't and found no increased likelihood of having received a flu shot during the four weeks before the miscarriage compared to those who had no miscarriage. Thirty-eight women who had a miscarriage received the flu shots compared to 31 who had not miscarried, which is not a statistically significant difference.

A study at the University of Utah showed that a mother who is vaccinated against the flu passes on the antibodies caused by the vaccine to her baby, who is protected for up to four months after being born. The study is important because a newborn cannot be vaccinated for at least six months and can experience a higher risk of complications if infected with influenza.

"Our research suggests that maternal vaccination does provide some protection from the flu for a few months after birth," Julie H. Shakib, the lead author of the study, said, according to Medical News Today. "Pregnant women should receive the vaccine as soon as it becomes available to protect themselves as well as their babies."

A study carried out at Christiana Care Health System in Newark, Del., found that pregnant mothers seem to be getting the message about the benefits and safety of the flu vaccine. The study, which involved 300 pregnant women, found that before 2009, less than 15 percent got vaccinated, compared to 55 percent after 2010.

"Pregnant women are one of the groups identified as a priority for receiving the influenza vaccine, but historically have been the least likely among those groups to get the vaccine," Nuezil said, according to Medical News Today. "It's good to learn the message of the importance of vaccination is getting through to pregnant women, and this research should provide even more comfort."