WASHINGTON, March 31 (UPI) -- A flu shot during pregnancy cuts the risk for stillbirth in half, according to a large study of mothers in Western Australia.
Researchers at the Department of Health in Western Australia found the influenza vaccine lowered the risk after a review of Australian births during two consecutive seasonal flu epidemics, they report in the journal Clinical Infectious Diseases.
Pregnancy makes women more susceptible to illness, including the flu, researchers said, noting the new study's results echo one conducted in Switzerland in 2000 that showed stillbirths increased during the flu season there.
"The findings support the safety of influenza vaccination during pregnancy, and also suggest that vaccination protects against stillbirth," Annette Regan, communicable disease control directorate project officer at the department of health in Western Australia, said in a press release. "With more than three million stillbirths occurring worldwide each year, establishing a connection between influenza season, vaccination and stillbirth could have global implications for infant mortality."
For the study, researchers analyzed records on 58,008 births in Western Australia between April 2012 and December 2013. Among the women, 8.8 percent had received the flu vaccine, and 377 stillbirths occurred at a rate of 5.0 per 100,000 pregnancy days for women without the vaccine and 3.0 per 100,000 days for women who received the vaccine.
Overall, stillbirth was 51 percent less likely among vaccinated mothers, as opposed to unvaccinted mothers, with the largest reduction in stillbirths coming just after flu season ended.
"While further research is needed to confirm these links, the findings of this study should encourage expectant mothers and health care providers to discuss the safety and benefits of receiving the influenza vaccine during pregnancy," Regan said.