Why The Study Linking Flu Shots to Miscarriages Shouldn’t Stop You From Getting The Vaccine

Why The Study Linking Flu Shots to Miscarriages Shouldn’t  Stop You From Getting The Vaccine

Hear that report suggesting that the flu shot is linked to miscarriages? Before you skip your shot, listen to what experts have to say about why you should still get vaccinated.

Don’t Believe That Flu Shot, Miscarriage Link

Flu Shot May Not Really Cause Miscarriage

Experts: Holes in Miscarriage, Flu Shot Study


“With flu season in full swing, September is possibly the worst time to release a confusing study about the safety of flu shots for pregnant women. But that’s what happened, and now doctors across the country are running defense to protect pregnant women and their babies from the flu,” Robyn Horsager-Boehrer, M.D., an OB/GYN and maternal-fetal medicine specialist, wrote in a statement online. The original study was published in Vaccine.

“The most important thing I want women to understand is this: This study does not say that you are at increased risk for miscarriage if you are in the first trimester, have a healthy pregnancy, and get a flu shot,” Horsager-Boehrer wrote.

Nanette Santoro, a professor at the University of Colorado, also thinks women should get the shot.

“Based on the data, and the slight change in how miscarriages were recorded in this study as compared to prior studies, we can’t be sure the findings are ‘real’ and can’t think of a biological reason why the flu shot should cause miscarriages,” she said. “The message we don’t want to communicate is that women should not get a flu shot when pregnant. Influenza can be life-threatening for pregnant women, especially when they are in their third trimester.  So for women who have any respiratory or immune compromise, they should not change their approach to immunization at all!”

In the study, researchers looked at 485 pregnant women, ages 18 to 44, who had a miscarriage and compared them to 485 pregnant women of similar ages who had normal deliveries during the 2010-2011 and 2011-2012 flu seasons. Of those who lost their babies, 17 had received flu vaccine in the 28 days before the miscarriage, and had also received the vaccine during the prior flu season. In those with normal deliveries, just four had the vaccine.

“The study did not specify when the women who got flu shots were vaccinated, but it stated that many received a flu shot within 28 days of the miscarriage and also received a flu shot during the previous year’s flu season,” she added.

“We only saw the link between vaccination and miscarriage if they had been vaccinated in the season before,” said James Donahue, an epidemiologist and lead author, told the Washington Post.

“Scientifically, it is unclear why this would occur. There was no association seen with a pregnancy loss more than 28 days after vaccination,” Haywood L. Brown, M.D., president of the American College of Obstetricians and Gynecologists (ACOG), said in a statement. When the vaccination was given either later in the first trimester or in the second or third trimester, there was no link to miscarriage or any other adverse pregnancy outcomes, he noted.

Verdict: Get Vaccinated

Women should still receive the vaccine—and it’s “particularly important” during pregnancy, Brown added. He noted that the vaccine is the most effective strategy to protect newborns because it cannot be administered to infants younger than six months.

The Centers for Disease Control and Prevention (CDC) and its Advisory Committee on Immunization Practices said it has not changed the recommendation for influenza vaccination of pregnant women.

In a statement, the CDC said the study does not prove flu shots can cause miscarriage. They noted that earlier studies did not find a link between flu vaccination and miscarriage.

“There is an ongoing investigation to study this issue further among women who were pregnant and eligible to receive flu vaccine during the 2012-13 through 2014-15 flu seasons. Results are anticipated in late 2018 or 2019,” the CDC said.

Hype or Health Hazard?

The authors say women should still get vaccinated but explained to other outlets they had to report on the facts despite the outrage over the study.

“I appreciate that researchers continue to question what is and isn’t safe for pregnant women and their babies. However, as medical professionals, we have to be careful about what we say and how we say it,” Horsager-Boehrer added. “This inconclusive study is a prime example of how associative data, particularly when it is distributed without proper context, can do more harm than good for public health.”

Serena Chen, M.D., a fertility specialist from New Jersey, noted that the study is the only one that has shown the association—and only for two particular years.

“Physiologically it does not really make sense why there would be an association between the flu shot and miscarriage,” Chen told HelloFlo. “We still have a lot of data demonstrating that the flu can be deadly to pregnant women so the benefits of the flu shot still clearly outweigh the risks for most women.”

Carolyn Thompson, M.D., a Nashville-based OB/GYN thinks that the advantages of getting the shot far outweigh the disadvantages, particularly since there seems to be healthy skepticism about the study.

“I am particularly skeptical about the perceived connection between serial flu shots and risk of miscarriage,” she said, noting that discussing the topic is appropriate.

She still recommends getting pricked.

“All this being said, I still am a strong proponent of flu shots for pregnant women,” Thompson added.

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