New Study Shows Benefits of Flu Vaccination During Pregnancy as Flu Vaccine Uptake in Pregnant Women Lags

November 09, 2022 — A new study reports that women who got a flu vaccine during pregnancy had a lower risk of certain negative birth outcomes, including fetal death (stillbirth), preterm birth and low birthweight. While CDC recommends flu vaccination during pregnancy, flu vaccine coverage among pregnant women in the United States has fallen 8 percentage points in the past two seasons and preliminary coverage for this season indicates vaccination is down another 5 percentage points from this time last year. This study adds to the body of evidence supporting the benefits of flu vaccination during pregnancy for both mother and baby. With flu activity increasing, now is a good time to get a flu vaccine.

Researchers retrospectively analyzed data from the Ministry of Health in New Zealand; a nation located in the Western Pacific region of the world with suboptimal flu vaccine coverage among pregnant people. The study population included female residents of reproductive age in that country who were pregnant between January 1, 2003, and December 31, 2018. This collaborative study with The University of Auckland and Abt Associates sought to 1) examine the association between acute respiratory infection (ARI) hospitalization during flu season and negative birth outcomes and 2) measure the association between flu vaccination and birth and pregnancy outcomes.

This analysis of 16 years of data published in the Official Journal of the International Society for Influenza and other Respiratory Virus Diseases found flu vaccination during pregnancy was associated with a lower risk of fetal death (stillbirth), preterm delivery and infants born with low birth weight. Previous studies have found that flu vaccination can lower risk of flu illness and flu-related hospitalizations in pregnant people.

These findings further support the value of flu vaccination in pregnant people. CDC recommends annual flu vaccination for everyone 6 months and older, including pregnant people who are at higher risk of severe flu.