A Landscape Analysis of Post-Marketing Studies Registered in the EU PAS Register and ClinicalTrials.gov Focusing on Pregnancy Outcomes or Breastfeeding Effects: A Contribution from the ConcePTION Project.

Introduction: A large proportion of medicine product labels lack information on safety in pregnancy and breastfeeding. To address this gap, pharmaceutical companies are requested to develop post-approval studies regarding the use of drugs by pregnant and breastfeeding women.

Objective: Our study aims to review key features of observational studies in pregnancy and breastfeeding and their impact on the respective medicine product labels.

Methods: Observational studies focusing on the safety evaluation of medicines used during pregnancy and breastfeeding were selected from the European Union Register of Post-Authorization Studies (EU PAS register) and ClinicalTrials.gov. We extracted information on the variables of interest and performed an impact assessment on the respective label.

Results: A total of 141 observational studies were eligible. Of these, 63 studies (45%) were based on primary data collection and 55 studies (39%) on secondary use of health data. A small number of studies (8%) aimed to evaluate drug safety during breastfeeding. Studies using secondary data collection lasted around 2.9 years as opposed to 7.5 years' duration for studies using primary data collection. Only two product labels were updated based on the study results.

Conclusion: The duration is significantly longer for studies based on primary data collection, and these are also smaller in size (less power), whereas outcomes of interest are similar. For completed studies, the impact on the label was very low. Given the gap in adequate pregnancy information on product labels, the current process of generating evidence in pregnancy and breastfeeding seems neither efficient nor impactful. To support evidence-based decision making by prescribers, this current process might be redesigned.