Pertussis is a highly contagious infectious disease caused by the bacteria Bordetella Pertussis. Although all age groups are susceptible to this disease, infants less than three months old are the most at risk. To prevent neonatal infection, Switzerland recommends Tdap immunization during pregnancy since 2013. Although multiple studies have shown the effectiveness of this antenatal maternal immunization, one recent study suggested it could result in a higher risk of developing chorioamnionitis (CA). Our study was made to evaluate the risk of developing CA in women who received antenatal Tdap immunization versus those who did not undergo immunization during pregnancy, and to analyze the risk of this antenatal immunization on other neonatal complications. It included 724 women with singleton live birth pregnancies who gave birth at the Geneva University Hospitals (HUG) between July 15th 2014 and July 17th 2016. Finally, this study showed no association between maternal Tdap immunization and CA.