There is now even more good news about the seasonal flu vaccine and how it can prevent severe infections in pregnant women. As I’ve said before, pregnant women and infants are at most risk of complications from the flu (even more from H1N1), and both groups are strongly recommended to get the annual flu shot. Unfortunately, the vaccination rate among pregnant women is very low. But the vaccine’s safety is not in doubt, and in fact, the flu vaccine not only can save the life of the mom but also the fetus. New studies now show that the flu shot during pregnancy not only protects the fetus and the newborn during those crucial first 6 months, but also that newborns have higher, healthier birth weights in vaccinated moms. Here’s a good quote from the review article (Seasonal Flu Vaccine for Pregnant Mothers Protects Infants ):

“Babies born to mothers who got the flu vaccine were on average half a pound heavier, which is not a trivial amount,” said lead author Mark C. Steinhoff, MD, from the Cincinnati Children’s Hospital Medical Center in Ohio. Dr. Steinhoff said this effect was seen only during periods when the flu virus was circulating. “The effect [in this study] was specific to the vaccine and the season. The benefits are seen in the mother and the infant, and now we see that it benefits the fetus,” he stated.

Why such a large and healthy increase in birth weight? The assumption is that the unvaccinated moms are getting sick from the flu and therefore losing weight and health during crucial development times for the fetus. But I think the more important stats are those that showed prevention of flu-related hospitalization in 79.8% of all infants (0 to 12 months old) and in 85.3% of those younger than 6 months of age. Since the flu vaccine is not indicated until 6 months of age for infants, and infants 0-6 months are most at risk for flu complications, it makes sense for moms to do everything possible to transfer their own antibodies (including from vaccines) during those critical first 6 months of life. So, if you’re pregnant, ask your ob/gyn doctor about the flu vaccine! And if your doctor hems and haws about “safety”, tell them to get up to speed on the real data, or find a better informed doctor. Here’s the official CDC statement:

Pregnant women and newborns are at risk for influenza complications, and all women who are pregnant or will be pregnant during influenza season should be vaccinated. The American College of Obstetricians and Gynecologists and the American Academy of Family Physicians also have recommended routine vaccination of all pregnant women. No preference is indicated for use of TIV that does not contain thimerosal as a preservative (see Vaccine Preservative [Thimerosal] in Multidose Vials of TIV) for any group recommended for vaccination, including pregnant women. LAIV is not licensed for use in pregnant women. However, pregnant women do not need to avoid contact with persons recently vaccinated with LAIV.