There’s some good news for pregnant women. Swedish researchers say that the H1N1 “swine flu” vaccine, named Pandemrix, does not cause any birth defects. Experts who reviewed the study agree, saying that these findings should ease concerns women still might have about this particular immunization.
Dr. Jennifer Wu, an obstetrician at Lenox Hill Hospital in New York City, said that,
This year’s flu vaccine includes protection against an H1N1-like virus.
H1N1 infamously caused a worldwide panic from 2009 to 2010 as “swine flu” swept across the United States. The virus appeared to be a new influenza strain that combined bird, swine and human flu viruses with a pig flu virus.
This new study “indicates that first trimester administration of H1N1 vaccine does not seem to increase congenital birth defects, US Health and World News reports.
The US Centers for Disease Control and Prevention recommends that all pregnant women receive a seasonal flu vaccine since they are especially susceptible to flu complications.
Led by Dr. Jonas Ludvigsson of the Karolinska Institute in Stockholm, the research studied the risks of birth defects, looking at overall conditions, congenital heart disease, cleft palates and limb abnormalities in over 40,000 children whose mothers had received the H1N1 vaccine.
The researchers compared the children to their siblings and to other children in the general population. They found that there was no indication that vaccinating pregnant women increased the overall risk of babies born with birth defects.
Wu said that looking at risks for vaccines given in a woman’s first trimester is important, as this is when early organ development happens, making the embryo especially vulnerable to anything that might disrupt its growth and cause defects.
Pandemrix was developed by GlaxoSmithKline and was first approved for use in 2009 by the European Commission specifically to combat the swine flu pandemic at the time.
The new study was published in the Annals of Internal Medicine.