Seasonal influenza occurs every year and millions of pregnant women
risk severe illness during seasons with a more aggressive strain.
Regulatory agencies in Europe and the USA therefore recommend
neuraminidase inhibitors for pregnant women with confirmed or suspected
influenza, or those exposed to close contacts with the illness, despite
limited knowledge on their safety and effectiveness during pregnancy.
‘There are no increased risks to newborn babies if their mothers have taken drugs to prevent or treat influenza during pregnancy.’
A study published by The BMJ
today finds no increased risks
to newborn babies if their mothers have taken drugs to prevent or treat
influenza during pregnancy.
This is the largest study to date to assess potential risks of
taking antiviral drugs (known as neuraminidase inhibitors) during
pregnancy and the results support previous findings. So a team of researchers based in Scandinavia and France decided to
assess risks of adverse birth outcomes in association with neuraminidase
inhibitors during pregnancy.
The study involved almost 6,000 women who were prescribed any of the
two neuraminidase inhibitors, oseltamivir or zanamivir, during
pregnancy - and almost 700,000 women who did not receive prescriptions
during a pregnancy in the same period (2008 to 2010).
After several health-related factors were taken into account, such
as age, smoking and use of other medications, the team found no
increased risks of adverse outcomes including low birth weight, low
Apgar score (a test of a baby's condition at birth), preterm birth,
stillbirth, or birth defects.
The findings remained the same when the analyses were restricted to oseltamivir exposure only.
The researchers point out that their study included some limitations
that could have influenced the findings. For example, the study did not
assess risks of adverse outcomes before 22 weeks of pregnancy, and some
women could have filled a prescription without taking the drug.
However, they say their results "support previously reported
findings that the use of neuraminidase inhibitors is not associated with
increased risks of adverse fetal or neonatal outcomes."