Pregnant women at increased risk of serious flu-related complications

WASHINGTON - An extensive review of published research and data from previous flu seasons has revealed that pregnant women who catch the flu are at a serious risk for flu-related complications, including death.

The review, conducted by scientists from the Johns Hopkins Children’s Center, Emory University and Cincinnati Children’s Hospital, found substantial and persistent evidence of high complication risk among pregnant women infected with the flu virus, while confirming vaccine safety.

The researchers say that the findings solidify existing Centers for Disease Control and Prevention (CDC) recommendations that make pregnant women the highest-priority group to receive both the H1N1 and seasonal flu vaccines.

“The lessons learned from flu outbreaks in the distant and not-too-distant past are clear and so are the messages. If you are an expectant mother, get vaccinated. If you are a physician caring for pregnant women, urge your patients to get vaccinated,” says lead author Pranita Tamma, M.D., an infectious disease specialist at the Johns Hopkins Children’s Center.

Tamma says that even though there are still no published data on the safety of the new H1N1 vaccine, experts believe it to be just as safe as the seasonal flu vaccine because “the H1N1 vaccine is manufactured in the same rigorous way as the seasonal flu vaccines and we expect it to have a very similar safety profile as the other flu vaccines.”

In their extensive review of data from three past flu pandemics and 11 published research studies on vaccine safety outcomes over 44 years, the researchers found no increased risk of either maternal complications or bad foetal results from the inactivated (injection) flu vaccine.

Researchers point out that even though study after study has found no link between the vaccine stabilizer thimerosal and autism, thimerosal-free injectable versions of the flu vaccine are available for those who have lingering concerns.

In their review, researchers say four studies have found evidence that antibodies protective against the flu, developed by the mother after vaccination, cross the placenta and transfer some protection to the foetus that lasts up to six months after birth.

Because pregnancy causes a variety of changes in the body, most notably decreased lung capacity, along with increased cardiac output and oxygen consumption, it puts pregnant women at high risk for complications.

In addition, parts of the mother’s immune system are selectively suppressed, a process that offers essential protection to the foetus, but decreases the mother’s ability to fight off infection.

The study has been published online in the American Journal of Obstetrics and Gynecology. (ANI)