THURSDAY, Oct. 11, 2018 (HealthDay News) -- The flu shot reduces a pregnant woman's risk of hospitalization for flu by 40 percent, new research shows.
"Expecting mothers face a number of threats to their health and the health of their baby during pregnancy, and getting the flu is one of them," said study co-author Allison Naleway, of Kaiser Permanente Center for Health Research, in Portland, Ore.
These "findings underscore the fact that there is a simple, yet impactful way to reduce the possibility of complications from flu during pregnancy: get a flu shot," Naleway added in a news release from the U.S. Centers for Disease Control and Prevention.
Investigators, including CDC researchers, analyzed 2010-2016 data from more than 2 million pregnant women in the United States, Canada, Australia and Israel.
The flu shot was equally protective during all three trimesters, and among women with health problems such as asthma and diabetes, the researchers said.
More than 80 percent of the pregnancies in the study overlapped with flu season, highlighting the fact that many mothers-to-be are exposed to the virus at some point during pregnancy.
Previous studies have shown that a flu shot can reduce the risk of flu in pregnancy. This study shows vaccination also reduces the risk of hospitalization for flu-related complications, such as pneumonia.
Flu poses a heightened risk in pregnancy due to changes to the immune system, heart and lungs. And women remain highly susceptible to flu-related illness for two weeks after pregnancy, according to the CDC.
In addition, a flu shot during pregnancy also protects babies for several months after birth, before they are old enough for their own flu vaccination.
Only about half of pregnant women in the United States reported getting a flu shot during recent flu seasons. The CDC and other public health agencies want to increase that number, and recommend women get vaccinated during any trimester of pregnancy.
But pregnant women should be sure to get a flu shot, not the nasal spray flu vaccine, the CDC recommends.
The new findings were published Oct. 11 in the journal Clinical Infectious Diseases.
The March of Dimes has more on the flu and pregnancy.