reassurance did not change participants initial impressions of acceptability. Conclusion Conducting a human challenge study in pregnancy would be acceptable to some pregnant women and may offer a means to investigate the specific environment that surrounds commensalisation of neonates. Furthermore, this may offer new avenues to explore vaccine development for the prevention of neonatal infection. While participants would want the maximum amount of information available before considering whether to participate, initial aversion to this methodology it is unlikely to be changed.