BMJ: 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. 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.
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.”