Whooping cough vaccine safe in pregnancy

August 4, 2014

Pregnant women given pertussis vaccination in their third trimester to prevent infections in newborns, should be reassured that the vaccine is safe, and in fact, may be beneficial, according to a study published in The BMJ online July 11, 2014.

Pregnant women given pertussis vaccination in their third trimester to prevent infections in newborns, should be reassured that the vaccine is safe, and in fact, may be beneficial, according to a study published in The BMJ online July 11, 2014.

In a retrospective study, a cohort of vaccinated pregnant women were identified using data from the Clinical Practice Research Datalink, a large electronic healthcare records database covering approximately 8% of the United Kingdom population.  Study participants included 20,074 pregnant women with a median age of 30 years who received the pertussis vaccine and a matched historical unvaccinated control group immediately prior to the start of the vaccination program as well as known rates taken from national data where available.

Vaccines are not routine evaluated in pregnancy during clinical development and when the United Kingdom introduced a new vaccination program against pertussis targeting pregnant women, it was imperative that a proactive approach was taken to monitor safety both to identify any important risks but also to provide reassuring data on safety in their absence to support the program and protect infants against pertussis, according to the lead author of the study Katherine Donegan, pharmacoepidemiologist, Medicines and Healthcare Products Regulatory Agency.

“There is no evidence of an increased risk of any of an extensive predefined list of adverse events [stillbirth, maternal or neonatal death, pre-eclampsia or eclampsis, hemorrhage, fetal distress, uterine rupture, low birth weight, etc.] related to pregnancy associated with pertussis vaccination when administered to pregnant women in their last trimester,” Donegan said. “In particular, there is no evidence of an increased risk of stillbirth.”

Whooping cough is highly infectious and babies are most at risk of severe complications and death, according to Donegan.

“Vaccinating pregnant women has been highly effective at preventing disease and deaths in young babies,” she said. “But, sadly, in the United Kingdom and elsewhere, we are still seeing deaths in newborns whose mothers did not receive the vaccine for whatever reason. If worry over vaccine safety is a factor in some women not having the vaccine then the results from our large study should help provide reassurance that the vaccine is safe in pregnancy, as well as very beneficial.”