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By now, you've probably heard reports that many pregnant women are more vulnerable than most to the swine flu virus, but it's not only viral infections they should worry about. Bacterial infections can also be dangerous.
NPR's Patti Neighmond looks at the risks of those infections and concerns about some of the antibiotics used to treat them.
PATTI NEIGHMOND: Pregnancy can weaken the immune system, which may be one reason why pregnant women are more vulnerable to bacterial infection. Dr. Brian Mercer heads obstetrics at Cleveland's Metro Health Medical Center.
Dr. BRIAN MERCER (Department of Obstetrics, Cleveland's Metro Health Medical Center): Pregnant women who develop a bladder infection are more prone to developing kidney infections, and pregnant women who develop pneumonia are at higher risk of complications from the infection itself.
NEIGHMOND: And those complications can harm the developing fetus.
Dr. MERCER: The infections themselves can carry a risk to the fetus because they can cause fever, and fever is - can lead to miscarriage and birth defects and early labor. Also, infections such as pneumonia can reduce the oxygen supply to the pregnancy and increase the chance for fetal loss.
NEIGHMOND: But there are some cautions with treating this infections. A study this month from the federal government finds most common antibiotics are safe. But it raises a red flag with two types of antibiotics: sulfa drugs like Bactrim and urinary germicides like Macrobid, which are typically used to treat urinary tract infections. In the study, women who had children with birth defects like heart problems, hernias or a cleft palate were more likely to have taken these medications.
Dr. Michael Katz with the March of Dimes says pregnant women shouldn't panic, but they should be careful.
Dr. MICHAEL KATZ (March of Dimes): It's reassuring to see that commonly used antibiotics are not problematic, but some of the rarer antibiotics may be. And the key question is: Is the antibiotic needed? And if it is needed, has it been checked for its potential toxicity?
NEIGHMOND: And doctors can do their part, says Katz, by doing a culture and figuring out exactly what type of bacteria is infecting the pregnant woman. Mercer says this is particularly important to do during the first trimester.
Dr. MERCER: The first trimester is the time when the organs are actually developing. It's the time when a heart becomes a heart and lungs become lungs. After that time, much of the pregnancy is taken up with further development of the organs that are already formed.
NEIGHMOND: In New York City, Dr. Mark Evans is an OB/GYN and geneticist who specializes in high risk pregnancies. He says doctors should be aware that certain antibiotics may cause harm.
Dr. MARK EVANS (OB/GYN and Geneticist): Everything is a balance between trying to minimize the risk to the fetus on one hand, but on the other hand, not winding up with a very sick mother who, in turn, will risk the fetus on the other hand. And so it is difficult, and one has to be judicious. And that's why you start with the safest medication that is most likely to do the job.
NEIGHMOND: Bottom line, says Evans, the antibiotics in question were not proved to cause birth defects. Researchers only raised concerns. Evans says further studies are needed. But in the meantime, birth defects remain uncommon, affecting two to three percent of all newborns.
Patti Neighmond, NPR News.
INSKEEP: And that's Your Health for this Monday morning.
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