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"Can the flu cause a miscarriage?"


Can a bout of the flu bring about a miscarriage? I haven't actually had the flu yet, but I am 6 months pregnant. On one hand, I'm worried about how the flu vaccine would affect my baby, but on the other hand, I know I have to be careful about how badly the flu could hurt her, too.


You should most definitely get vaccinated. For many years, infection with influenza virus has been known to be WORSE in pregnant woman and can definitely cause harm to the mother and fetus, including miscarriage. This is postulated to be because pregnant woman have decreased immune systems (compared to age-matched non-pregnant woman).

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This is biologically understandable; you would want to lower your immune system so that your body does not react against the proteins of the fetus are are recognized as "foreign" to your immune system. If there is a vaccination shortage, pregnant women are in fact one of the designated groups to STILL receive the vaccination. This reflects a thorough analysis of the data by the national committee charged with making annual vaccination recommendations (for all vaccines, not just influenza). The vast majority of influenza virus vaccinations are the trivalent (protects against 3 strains of the virus that are predicted to be circulating during the 2010-2011 flu season, including the 2009 H1N1 swine influenza virus) inactivated virus. This means that the vaccination, which delivered as an intramuscular injection, cannot cause the disease. Additionally, there is a live attenuated virus vaccination that is delivered via a nasal spray. There are some reports of this vaccine causing illness because it is a live influenza virus that has been attenuated (decreased activity). I would imagine that most Ob/Gyn doctors would not give this type of vaccination to pregnant women. I would encourage you to get vaccinated as soon as possible by the Ob/Gyn following your pregnancy. She/he can provide you with more information about the vaccination, including the small (but present) risks of the vaccination for you to consider with your physician.

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