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NCT Number: NCT06258057

Safety of Tetanus, Diphtheria, Acellular Pertussis With 5 Acellular Pertussis Components (Tdap5) Vaccination During Pregnancy

The purpose of this study is to evaluate the safety of Adacel vaccine among pregnant individuals exposed to Adacel at any point between the 1st day of the 27th week of gestation up to the end of pregnancy and their offspring (ie, Adacel-exposed cohort), in comparison with pregnant individuals not vaccinated with any Tdap vaccines during pregnancy and their offspring (ie, Tdap-unvaccinated comparator cohort).

The primary objectives are to estimate incidence rates and relative risks for each prespecified pregnancy outcome in Adacel-exposed and Tdap-unvaccinated comparator cohorts and for each prespecified adverse birth outcome in the offspring of both cohorts.

The secondary objectives are to estimate incidence rates and relative risks for each prespecified adverse fetal and neonatal outcome in the offspring of Adacel-exposed and Tdap unvaccinated comparator cohorts and for each prespecified adverse outcome for pregnant individuals in both cohorts.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Pertussis (Whooping Cough) Bacterial Infections Bacterial Infections and Mycoses Bordetella Infections Gram-Negative Bacterial Infections Infections Respiratory Tract Diseases Respiratory Tract Infections Whooping Cough

Age range

15 year–49 year

Sex eligibility

Female

Study type

Observational

Primary location

Investigational Site

Chilly-Mazarin, 91380, France

About this study

This is a retrospective cohort study utilizing existing EHR data to identify eligible pregnant individuals, with an observation period spanning January 2016 through December 2024. Given this study design, follow-up for all pregnancies with documented deliveries is expected to be complete by December 2025.

The study report is expected to be completed by 31 December 2026.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • For pregnant individuals:
  • Continuous enrollment, with no more than a 1-month administrative gap from 90 days prior to their last menstrual period (LMP)
  • Continuous enrollment for the duration of their pregnancy through delivery or termination of pregnancy (or 6 weeks postpartum for preeclampsia/eclampsia and 28 days for PPH) unless censored at death in order to capture study outcomes
  • At least 1 prenatal visit prior to 27 weeks of gestation during pregnancy
  • For offspring:
  • Infants delivered by pregnant individuals who meet all the inclusion criteria above
  • With gestational age as calculated based on date of birth recorded in the EMR

Exclusion criteria

  • For pregnant individuals:
  • Loss of pregnancy or with delivery before 27 weeks of gestation
  • Vaccinated with Boostrix® (Tdap vaccine, GSK), or with an unknown brand of Tdap vaccine, or Td (tetanus, diphtheria) vaccine during pregnancy
  • Vaccinated with any Tdap vaccine prior to the ACIP recommended optimal timeframe of ≥ 27 0/7 weeks of gestation
  • Received more than one Tdap vaccine during pregnancy
  • Vaccinated with one or more live vaccines during pregnancy
  • Pregnant individuals with multiple gestation pregnancies (eg, twins, triplets)
  • For offspring:
  • Infants delivered by pregnant individuals who meet any of the exclusion criteria above

Treatment and study plan

Not applicable / database analysis

Other

Not applicable / database analysis

Primary outcomes

  1. Pregnancy outcome: Live birth

    Time frame: From 1st day of the 27th week of gestation up to 42 weeks gestation

    Incidence rates of live births in Adacel-exposed and Tdap-unvaccinated comparator cohorts

  2. Pregnancy outcome: Still birth/fetal demise

    Time frame: From 1st day of the 27th week of gestation up to 42 weeks gestation

    Incidence rates of still birth/fetal demise in Adacel-exposed and Tdap-unvaccinated comparator cohorts

  3. Pregnancy outcome: Therapeutic abortion

    Time frame: From 1st day of the 27th week of gestation up to 42 weeks gestation

    Incidence rates of therapeutic abortion in Adacel-exposed and Tdap-unvaccinated comparator cohorts

  4. Birth outcome: Preterm birth

    Time frame: From 1st day of the 27th week of gestation and less than 37 weeks gestation

    Incidence rates of preterm birth in live born infants of both Adacel-exposed and Tdap-unvaccinated comparator cohorts

  5. Birth outcome: Low birth weight

    Time frame: From 1st day of the 27th week of gestation up to 42 weeks gestation

    Incidence rates of low birth weight in live born infants of both Adacel-exposed and Tdap-unvaccinated comparator cohorts

  6. Birth outcome: Small for gestational age

    Time frame: From 1st day of the 27th week of gestation up to 42 weeks gestation

    Incidence rates of small for gestational age in live born infants of both Adacel-exposed and Tdap-unvaccinated comparator cohorts

Secondary outcomes

  1. Adverse neonatal outcome: Neonatal death

    Time frame: From birth up to 28 days post-birth

    Incidence rates of neonatal death in the offspring of Adacel-exposed and Tdap-unvaccinated comparator cohorts

  2. Adverse neonatal outcome: Neonatal sepsis

    Time frame: From birth up to 28 days post-birth

    Incidence rates of neonatal sepsis in the offspring of Adacel-exposed and Tdap-unvaccinated comparator cohorts

  3. Adverse neonatal outcome: Neonatal respiratory distress

    Time frame: From birth up to 28 days post-birth

    Incidence rates of neonatal respiratory distress in the offspring of Adacel-exposed and Tdap-unvaccinated comparator cohorts

  4. Adverse neonatal outcome: Congenital anomalies

    Time frame: From birth up to 28 days post-birth

    Incidence rates of congenital anomalies (major and minor) in the offspring of Adacel-exposed and Tdap-unvaccinated comparator cohorts

  5. Adverse neonatal outcome: Neonatal/early infancy intensive care admissions for bronchopulmonary dysplasia

    Time frame: From birth up to 28 days post-birth

    Incidence rates of neonatal/early infancy intensive care admissions for bronchopulmonary dysplasia in the offspring of Adacel-exposed and Tdap-unvaccinated comparator cohorts

  6. Adverse fetal outcome: Fetal growth arrest (restriction)

    Time frame: From 1st day of the 27th week of gestation up to 42 weeks gestation

    Incidence rates of fetal growth arrest (restriction) in Adacel-exposed and Tdap-unvaccinated comparator cohorts

  7. Adverse outcomes in pregnant individuals: Preterm labor

    Time frame: From 1st day of the 27th week of gestation and less than 37 weeks gestation

    Incidence rates of Preterm labor in Adacel-exposed and Tdap-unvaccinated comparator cohorts

  8. Adverse outcomes in pregnant individuals: Preeclampsia/eclampsia

    Time frame: From 1st day of the 27th week of gestation up to 42 days postpartum

    Incidence rates of preeclampsia/eclampsia in Adacel-exposed and Tdap-unvaccinated comparator cohorts

  9. Adverse outcomes in pregnant individuals: Postpartum hemorrhage

    Time frame: Within 24 hours of delivery up to 28 days postpartum

    Incidence rates of postpartum hemorrhage in Adacel-exposed and Tdap-unvaccinated comparator cohorts

  10. Adverse outcomes in pregnant individuals: Placental abruption

    Time frame: From 1st day of the 27th week of gestation up to 42 weeks gestation

    Incidence rates of placental abruption in Adacel-exposed and Tdap-unvaccinated comparator cohorts

  11. Adverse outcomes in pregnant individuals: Premature rupture of membranes

    Time frame: From 1st day of the 27th week of gestation up to 42 weeks gestation

    Incidence rates of premature rupture of membranes in Adacel-exposed and Tdap-unvaccinated comparator cohorts

  12. Adverse outcomes in pregnant individuals: Chorioamnionitis

    Time frame: From 1st day of the 27th week of gestation up to 42 weeks gestation

    Incidence rates of chorioamnionitis in Adacel-exposed and Tdap-unvaccinated comparator cohorts

Sponsors and collaborators

Lead sponsor

Sanofi

Industry

Registry information

Official study title

Safety of Tetanus, Diphtheria, Acellular Pertussis With 5 Acellular Pertussis Components (Tdap5) Vaccination During Pregnancy: A Cohort Study Using US Electronic Medical Record Data

Important dates

Study start
2024
Primary completion
2026
Study completion
2026
First posted
Feb 14, 2024
Registry last updated
Apr 6, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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