The rapid spread of variant H1N1, a.k.a. swine flu, has brought attention to previous pandemics of influenza in 1918 and 1957. In each of these flu episodes, pregnant women were particularly vulnerable. The incidence of pregnant women among those infected in the U.S. during the current epidemic of H1N1 is six times higher than in the population in general.
Lethal Complications of H1N1 for Pregnant Women
Prior outbreaks of swine flu and even seasonal influenza indicate that pregnant women and new mothers are vulnerable to pneumonia. During the 1918 flu pandemic approximately one quarter of pregnant women who became infected with flu subsequently died of pneumonia. Half of the deaths during the 1957 swine flu epidemic were pregnant women.
Why Pregnant Women and New Mothers are Particularly Vulnerable to H1N1
The growing fetus in a pregnant woman presses upward and compresses the lungs. Compression reduces the ability of the lungs to fill and expel fluid. As a result, pregnant women are susceptible to pneumonia.
Pregnancy and birth demand substantial changes in a mother’s immune system to accommodate a foreign body and subsequently to enhance inflammation enough to deliver a baby. These dramatic shifts in the immune system make a mother more vulnerable to infection and make flu infections more dangerous.
Prevention of Infection of Pregnant Mothers and Newborns is Imperative
Since infection poses high risks for pregnant mothers and their babies, the first priority to prevent infection. Isolation and hygiene must be encouraged. In England, women have been discouraged from becoming pregnant until after the current H1N1 outbreak has subsided. The CDC has not yet made that recommendation, but they do direct pregnant women to be vigilant about avoiding contact with infected individuals, to minimize contact of siblings with potential sources of infection and discourage visitors to new borns.
CDC Recommendations for Pregnancy and H1N1
- Start antiviral drugs promptly
- Isolate infected mothers from other pregnant women
- Cover mothers face with surgical mask before, during and after delivery
- Isolate mother after delivery
- Support breastfeeding
Initiation of Antiviral Drug is Imperative
The CDC also emphasizes rapid intervention for pregnant women who show symptoms of H1N1 infection. The variant H1N1 is currently sensitive to neuraminidase inhibitors, so early use of antiviral drugs, e.g. Oseltamivir, is recommended. The risks of antiviral drugs during pregnancy for mother and fetus, or for newborns have not been fully evaluated. The risks of untreated infections appear to be greater.
CDC Advises Breastfeeding to Protect Newborns
The CDC states in its guidelines for H1N1 that, “Breastfeeding should be protected and supported at all times because of the protection from respiratory infection that breast milk provides to the infant. “
references:
Considerations Regarding Novel H1N1 Flu Virus in Obstetric Settings
Novel Influenza A (H1N1) Virus Infections in Three Pregnant Women --- United States, April--May 2009
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