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Influenza Vaccine = Less Premature Birth

Reported June 2, 2011

(Ivanhoe Newswire) -- Researchers say there might be a link in pregnant mothers who receive the inactivated influenza vaccine, leading to a reduced risk of a premature infant and the baby being small for gestational age, which is the number of weeks the baby has been in the uterus.

The study found that babies who were born during the flu season, by mothers that were vaccinated against influenza during their pregnancy, were less likely to be premature. Researchers compared infants with mothers who didnít receive the vaccination, but were also born during flu season, which is October to May.

The study analyzed 4,168 mother and baby pairs. Researchers used a large surveillance dataset to analyze the relationship between the receiving of the inactivated flu vaccine during the pregnancy, by mothers of infants born between June 1, 2004 and September 30, 2006 and their baby being premature and small for gestational age.

Results showed compared with newborns of mothers without the vaccination, babies of vaccinated mothers had lower risk of being small for gestational age during the flu season. But researches did not find a significant effect on small gestational age babies during non-influenza periods.

However, the authors were quoted saying "Studies in other populations, particularly randomized controlled trials, are needed to confirm our results." The observational study can only show there is a link between flu vaccination and reduced risk of prematurity, and cannot demonstrate there is a casual link.

SOURCE: PLoS Medicine, May 31, 2011