The seasonal flu and the H1N1 flu are particularly dangerous during pregnancy. Pregnant women have a weakened immune system, so both strains of influenza can lead to a higher risk of complications like pneumonia.
While vaccinations for the swine flu and the seasonal flu may prevent pregnant women from contracting these viruses, antivirals can help reduce the risk of complications in women that do become ill. The Centers for Disease Control and Prevention (CDC) recently updated their guidelines for the use of Tamiflu and other antivirals during pregnancy. In addition, recent studies suggest that the use of the antivirals, oseltamivir (Tamiflu) or zanamivir (Relenza), is safe and effective in pregnant and breastfeeding women with the swine flu.
CDC Recommendations for Antiviral Treatment in Pregnant Women
The prevalence of both swine flu and seasonal flu has led the CDC to update its guidelines for antiviral treatment. The CDC recommends that patients with either H1N1 or seasonal flu with a high risk of complications be treated with either oseltamivir (Tamiflu) or zanamivir (Relenza). Treatment with antivirals should be started as early as possible, ideally within 48 hours of the onset of symptoms. It is recommended that antiviral treatment commence even before the laboratory has confirmation of influenza.
Safety of Tamiflu and Other Antivirals During Pregnancy
There are four antiviral medications currently approved in the United States for the treatment of the flu: amatadine (Symmetrel), rimantadine (Flumadine), oseltamivir (Tamiflu), and zanamivir (Relenza). All four antiviral medications are effective against influenza type A. Oseltamivir or zanamivir are effective against both influenza type B and the H1N1 flu.
So far, there have not been any large clinical studies in humans assessing the safety of these antivirals during pregnancy. Animals studies have shown that rimantadine, oseltamivir, and zanamivir do not seem to cause any problems during pregnancy. In animals, amatadine may lead to an increase in adverse pregnancy outcomes. However, reports of women that received this drug during pregnancy suggest that it does not lead to an increase in birth defects.
A recent study published in the Canadian Medical Association Journal looked at the safety of Tamiflu and Relenza in pregnant and breastfeeding women. A literature search was performed to identify reports of the use of these drugs during pregnancy. The authors note that Tamiflu should be the drug of choice for pregnant women because there is more data available supporting its safety during pregnancy.
The use of antiviral medication may help prevent complications of the seasonal and swine flu in pregnant women. Although the safety of these drugs has not been thoroughly evaluated in the clinical trial setting, there is some information available to support that the use of antiviral drugs during pregnancy is safe for the mother and baby. Women that are diagnosed with seasonal or H1N1 influenza during pregnancy should weigh the pros and cons of antiviral therapy with their physicians.
References
Tanaka T, et al "Safety of neuraminidase inhibitors against novel influenza A (H1N1) in pregnant and breastfeeding women" CMAJ 2009
Organization of Teratology Information Specialists: "Antiviral Medications to Treat/Prevent Influenza (Flu) and Pregnancy"
Megan Doyle - Megan is very passionate about learning. She enjoys keeping up to date with and writing about breakthroughs in the fields of health and ...
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