The H1N1 flu virus, which circulated during the 2009-2010 flu season, was especially deadly for pregnant women. An article in the New England Journal of Medicine revealed that of the 1088 H1N1 patients who were hospitalized, or died, in five months in 2009, 10% of them were pregnant women. This is a huge number considering that only 1% of the general US population is pregnant on a single day. In fact, about 6% of the deaths due to H1N1 were pregnant women.
The article also concluded that pregnant women with H1N1 appeared to become sicker much faster than other H1N1 after being identified with mild flu symptoms.
While pregnant women are recommended to get the seasonal flu vaccine, before H1N1, the death of pregnant women due to the flu was relatively rare. This may have lead to less aggressive treatment of flu symptoms among pregnant women infected with the H1N1 flu virus.
Obstetricians are encouraged to give their pregnant patients the seasonal flu vaccine, though this does not occur at optimal rates. Besides benefitting the mother, the seasonal flu vaccine also reduces flu-like illness in babies less than 6 months of age by 63%.
This year the CDC is strongly encouraging pregnant women to get the seasonal flu vaccine (which contains protection against H1N1). Pregnant women are only allowed to get the flu shot, in lieu of the flu nasal spray, and there are mercury free flu shots for women concerned about the mercury in thimerosal.
Some clinics are offering free flu shots for seniors and people with disabilities, and the CDC recommends that everybody above the age of 6 months get the vaccine.
Given that H1N1 is expected to circulate in some form again during the 2010-2011 flu season, it is unknown exactly how this year’s flu will effect pregnant women. Even if you got the flu shot last year, you need to get it this year as well for the highest level of protection. As about 200,000 Americans are hospitalized for the flu, getting the vaccine makes sense.
N Engl J Med 2010; 362:27-35
January 7, 2010