Pregnant women are at risk from flu

DALLAS — Flu cases among young pregnant women surged at a large public hospital, calling attention to yet another group at serious risk of the flu.

About 80 expectant mothers have been diagnosed with the flu since early October, said Dr. Jeanne Sheffield, a maternal and fetal medicine specialist at Parkland Health and Hospital System. More than 60 were admitted, with one treated in the intensive care unit, she said.

Pregnancy weakens a woman’s immune system, making her more vulnerable to the virus. Only two of the women had the flu shot, and they had it just before they became ill, so they were not protected.

But Sheffield said it is rare to see so many pregnant women get sick. Most were in their teens and early 20s; all recovered and are out of the hospital.

"Maybe we may have admitted five or 10 a year in the past," Sheffield said. "This is much different than normal."

It isn’t clear why Parkland had so many flu cases among pregnant women. Some health officials speculate that it’s because Parkland — with 15,000 births annually among the leading hospitals for deliveries — is a large public hospital that treats many uninsured people. Its patients are less likely to see a doctor regularly or early in an illness, Sheffield said.

A Texas Department of Health survey found no other serious outbreaks among pregnant women in the state, and the Centers for Disease Control and Prevention has not heard of any similar outbreaks in the nation.

Sheffield believes Parkland also is being more aggressive about testing for the flu than other hospitals. Testing was done on all pregnant women who showed flu symptoms after one sick woman with an unusually high heart rate was diagnosed with it in October.

"Suddenly all of us were very aware that influenza was around, and it was affecting our pregnant women," she said. "We jumped on it very, very quickly."

Among the states with major flu outbreaks, Texas was the first where the virus was widespread. That may explain why Dallas is the first to report such a high number of ill pregnant women, said Dr. Tim Uyeki, a CDC epidemiologist.

"Any type of infection can lead to pre-term labor," Sheffield said, adding that the flu can progress to more dangerous infections such as pneumonia or meningitis.

While flu shots are encouraged for everyone, women in their second and third trimesters are among those at high risk, along with women at any stage of pregnancy who are HIV-positive.

Parkland began a vaccination campaign among pregnant women when doctors noticed the upswing in cases, Sheffield said, and free shots are offered to all pregnant women treated at the hospital or any of its community clinics.

The number of flu cases began to taper off last week, the doctor said.