Out of 347 pregnant women in 2009 with severe pandemic flu, 75 died, and 272 were admitted to an ICU and survived the illness, according to a MMWR report by the CDC (Centers for Disease Control and Prevention). The authors stressed that pregnant mothers with influenza have a higher risk of being hospitalized and dying.

For the last seven years ACIP (Advisory Committee on Immunization Practices) has recommended that all pregnant women receive the inactivated influenza vaccine, no matter what trimester they are in.

In 2004, when the ACIP recommendation was issued, only about 15% of pregnant mothers received a flu jab. This percentage went up to 50% in 2009, the year of the A (H1N1) influenza pandemic, also known as the swine flu pandemic.

For the last two years the CDC says it has collaborated closely with state and local health authorities to carry out enhanced surveillance for severe flu among women who are pregnant, as well as those who have recently given birth.

The authors reveal that more pregnant mothers with swine flu who received antiviral treatment promptly survived compared to the other infected pregnant women. They also report that hospitalized infected women who gave birth during their hospitalization had a much higher risk of doing so prematurely, and to babies of low birth weight.

Mothers who were hospitalized, got better and went home, were more likely to give birth to infants of low birth weight, compared to pregnant women in the general population.

The authors say their findings underline the importance for pregnant mothers to make sure they are vaccinated against flu, as well as the timely administration of antiviral medications to those who do become infected.

This report only includes pregnant women with severe illness during the pandemic period - April 15, 2009 to August 10, 2010. Severe illness means those who either died or were admitted to an ICU (intensive care unit).

Below are some highlighted details from their report:
347 women had severe illness
272 women were admitted to the ICU and did not die
75 women died
49.8% of those with severe illness had underlying medical conditions
61.5% of those in the ICU with underlying conditions died, compared to 46.7% with no underlying conditions
Of those who died, 86.1% were given antiviral treatment with a neuraminidase inhibitor
Among those who survived, 94.8% were given antiviral treatment with a neuraminidase inhibitor
Only 7% (4) of the women who died received treatment with a neuraminidase inhibitor within two hours of becoming ill
40.6% of those who survived received treatment with a neuraminidase inhibitor within two hours of becoming ill
Examples of underlying conditions include asthma, pregestational/gestational diabetes or hypertention, cancer, chronic lung disease, autoimmune disease, neurologic disease, thyroid conditions, and kidney conditions.

They found no link between risk of death from severe flu illness and race, trimester of illness onset, or age.

Written by Christian Nordqvist