Pregnant women infected with swine flu have a markedly higher risk of death than the general population and need to get to a doctor straight away if they suspect they have the flu, concludes a study in the British medical journal The Lancet.
Furthermore, the study found that the rate of hospitalization for pregnant women is more than four times that of the general population.
The study is based on data collected and analyzed by the U.S. Centers for Disease Control and Prevention (CDC). The CDC data report on the first six deaths among pregnant women with H1N1, looking at the period between April 15 and June 16, 2009.
The pregnant women represent 13 per cent of the total 45 deaths reported to CDC during that time period.
While it's still not clear if pregnant women are more likely to catch swine flu, once they are infected, pregnant women seem to have a higher risk of complications.
All of the six pregnant mothers in the CDC study who died were healthy prior to infection of H1N1. One had asthma and another was obese but otherwise healthy.
All developed viral pneumonia which led to acute respiratory distress requiring the use of a ventilator to help them breathe.
The study found that all the women did not receive antiviral medications soon enough to benefit them. For that reason, the authors recommend that pregnant women with even a suspected case of swine flu be given prompt treatment with antivirals.
"The death of a pregnant woman is always heartbreaking, and unfortunately, we have been hearing reports of otherwise healthy women dying from H1N1," said CDC's Dr. Denise Jamieson, lead author of the study.
"If a pregnant woman feels like she may have influenza, she needs to call her healthcare provider right away."
Jamieson also says some doctors hesitate to treat pregnant women with antiviral medications because of concerns for the developing baby, "but this is the wrong approach," she says.
"It is critical that pregnant women, in particular, be treated promptly."
Doctors know that pregnant women are vulnerable to complications from seasonal flu and have increased rates of illness and death.
Despite recommendations from the Advisory Committee on Immunization Practices and the American College of Obstetricians and Gynecologists for inactivated flu vaccine for all pregnant women, seasonal flu vaccine coverage among pregnant women is very low (less than 14 per cent).
It's expected that pregnant women will be given priority when guidelines for the new swine flu vaccine are developed in Canada. Those guidelines are due soon.
Canadian doctors have also noticed that pregnant women are more at risk of complications. Earlier this month, Dr. David Butler-Jones, Canada's Chief Public Health Officer, said that while pregnant women are no more likely to contract the virus, infection increases their chances of pregnancy complications, including early delivery and miscarriage.
Shortly after, Health Canada released guidelines for health professionals on caring for pregnant women with H1N1, as well as a factsheet for pregnant mothers about how to prevent infection and when to seek medial care.
"We want to help inform pregnant women of the precautions they should take, like hand sanitizing and avoiding large crowds," said Butler-Jones.
