Pregnant women should take prescription flu medicines if they are diagnosed with the new swine flu, health officials said Tuesday.
So far, swine flu has not proven to be much more dangerous than seasonal flu, and pregnant women don't catch the virus more often than other people. But in general, flu poses added risks for pregnant women, said Dr. Anne Schuchat of the U.S. Centers for Disease Control and Prevention.
Pregnancy weakens a woman's immune system so she's more likely to suffer dehydration and pneumonia when she catches the flu. The virus also raises the risk for a premature birth, said Schuchat.
Risks from the virus are greater than the unknown risks to the fetus from the drugs Tamiflu and Relenza, Schuchat said at a press conference.
"We really want to get the word out about the likely benefits of prompt antiviral treatment" for pregnant women, she said.
Still, the flu medicines' effectiveness is somewhat limited, studies have shown. They can relieve symptoms and shorten the disease by about a day. They only work if started within 48 hours of first symptoms, and little is known about whether they cut the chances of serious flu complications. Most people recover from the flu with no medical treatment.
But a pregnant Texas woman who had swine flu died last week, and at least 20 other pregnant women have swine flu, including some with severe complications. The Texas woman also had other health problems — asthma and rheumatoid arthritis.
In total, about 3,000 U.S. cases of swine flu have been confirmed through lab testing so far, most of them ages 18 and under. Officials think the actual number of infections is much higher, and that infections are still occurring.
CDC officials said the swine flu may seem to be mild now, but they worry the virus will mutate into something more dangerous. One concern is that it will combine with the more deadly but less easily spread bird flu virus that has been circulating in Asia and other parts of the world.
Another concern is that it will combine with the seasonal virus that went around over the winter. That virus was not unusually virulent, but it was resistant to Tamiflu — the current first-line defense against the new swine flu. If the two virus strains combine, it's possible the swine flu will become resistant to Tamiflu as well, health officials worry.