The recommended timing of pertussis immunisation for pregnant women has been brought forward from 28 weeks to 16 weeks in order to improve infant protection and provide more opportunity for women to be offered the vaccine during pregnancy. A recent study has shown that maternal pertussis immunisation in the second trimester significantly increases neonatal antibodies.
In practice, the most appropriate time to offer pertussis immunisation will be after the foetal anomaly scan, which usually takes place between 18 and 20 weeks' gestation. Immunisation can be offered at any time after the scan.
Pertussis remains at heightened levels in the population. It is therefore critically important that women are offered the pertussis-containing vaccine in each and every subsequent pregnancy.