203153 - A post-marketing, observational, retrospective, cohort study to assess the safety of RefortrixTM (Tdap) when administered during pregnancy in a maternal immunization program in Brazil

Study type

• Study topic:
  Disease /health condition

  Human medicinal product
• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness
• Data collection methods:
  Secondary use of data

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Medicinal product name, other:
  RefortrixTM
• Medical condition to be studied:
  Gestational diabetes

  Stillbirth

  Congenital anomaly

  Preterm premature rupture of membranes

Population studied

• Short description of the study population:
  Exposed Cohort (cohort of pregnant women who received Refortrix as part of the maternal immunization program in Brazil); Unexposed Cohort historical cohort of unvaccinated pregnant women before the implementation of the immunization program)
• Age groups:
  • Adults (18 to < 46 years)
  • Adults (46 to < 65 years)
• Special population of interest:
  Pregnant women
• Estimated number of subjects:
  2462

Study design details

• Main study objective:
  To compare the risk of gestational diabetes, pregnancy-related hypertension and pregnancy haemorrhage in a cohort of pregnant women vaccinated with RefortrixTM as part of the maternal immunization program in Brazil (Exposed cohort) with a historical cohort of unvaccinated pregnant women before the implementation of this immunization program (Unexposed cohort).
• Outcomes:
  Occurrence of any of the pregnancy-related AEs in Exposed and Unexposed subjects after week 27 and any of the outcomes in neonates from Exposed and Unexposed subjects. After week 27 up to week 37 (for pre-term birth) and after week 27 (for small for gestational age). Occurrence of pregnancy-related AEs of interest/neonate-related events in Exposed and Unexposed subjects after week 27, occurrence of congenital anomalies in the neonates of Exposed and Unexposed subjects after week 27 up to birth and Occurrence of pregnancy-related AEs and birth outcomes per calendar year in the Unexposed cohort after week 27.
• Data analysis plan:
  The risk for each primary endpoint will be calculated. For each specific endpoint, the number of subjects where the event occurred will be divided by the total number of subjects at risk for both the Exposed and Unexposed cohorts respectively, together with its exact 95% confidence interval (CI).The co-primary endpoints of pregnancy will be pooled together and the co-primary endpoints of birth outcome will be pooled together. The analysis of the risk for the pooled endpoints will be performed using the same method as for the separate co-primary endpoints.The comparison of the risk with its two sided 95% CI of each primary endpoint between the Exposed cohort and the Unexposed cohort will be obtained by means of logistic regression model, using the exposure status as a binary independent variable in the model. Absence of increased risk will be concluded if this CI contains 1.