Pregnant Women and Swine Influenza Considerations for Clinicians

Health
Pregnant Women and Swine Influenza Considerations for Clinicians
By Copied from CDC.gov
May 2, 2009 - 6:26:36 PM

May 1, 2009 5:45 PM ET
Copied from CDC.gov (please see CDC.gov site for updates)

Background

Human infections with a swine influenza A (H1N1) virus that is easily transmissible among humans was first identified in April 2009. The epidemiology and clinical presentations of these infections are currently under investigation. There are insufficient data available at this point to determine who at higher risk for complications of swine influenza A (H1N1) virus infection. However, it’s reasonable to assume that the same age and risk groups who are at higher risk for seasonal influenza complications should be also considered at higher risk for swine influenza complications.

Evidence that influenza can be more severe in pregnant women comes from observations during previous pandemics and from studies among pregnant women who had seasonal influenza. An excess of influenza-associated excess deaths among pregnant women were reported during the pandemics of 1918–1919 and 1957–1958. Adverse pregnancy outcomes have been reported following previous influenza pandemics, with increased rates of spontaneous abortion and preterm birth reported, especially among women with pneumonia. Case reports and several epidemiologic studies conducted during interpandemic periods also indicate that pregnancy increases the risk for influenza complications for the mother and might increase the risk for adverse perinatal outcomes or delivery complications.

Clinical Presentation

Pregnant women with swine influenza would be expected to present with typical acute respiratory illness (e.g., cough, sore throat, rhinorrhea) and fever or feverishness. Many pregnant women will go on to have a typical course of uncomplicated influenza. However, for some pregnant women, illness might progress rapidly, and might be complicated by secondary bacterial infections including pneumonia. Fetal distress associated with severe maternal illness can occur. Pregnant women who have suspected swine influenza A (H1N1) virus infection should be tested (http://www.cdc.gov/h1n1flu/specimencollection.htm), and specimens from women who have unsubtypeable influenza A virus infections should have specimens sent to the state public health laboratory for additional testing to identify swine influenza A (H1N1).