This blog features:
- What are pregnancy registries?
- Why are pregnancy registries important?
- Their purpose and usefulness in clinical aspects of drug safety monitoring
- How pregnancy registries contribute to pharmacovigilance and long-term follow-up
Introduction
Pregnancy presents a unique challenge in medicine and pharmacovigilance. Pregnant women are often underrepresented in clinical trials, which means that information about the safety of medicinal products during pregnancy may remain limited when a product reaches the market.
For this reason, pregnancy registries also included as important sourceof report with in pharmacovivilance and clincial trials.
Pregnancy registries: An Overview
A pregnancy registry (more precisely, a pregnancy exposure registry) is an observational research study that systematically collects information about women who are exposed to a medicine or vaccine during pregnancy and follows pregnancy and/or infant outcomes.
Pregnancy registries can therefore complement the normal adverse-event collection mechanisms used in pharmacovigilance.
From a pharmacovigilance perspective, information obtained through pregnancy follow-up activities can contribute to the overall safety evaluation of a medicinal product.
“Pregnancy registries turn individual pregnancy exposures into structured safety evidence, helping pharmacovigilance teams understand risks that may only become visible through follow-up over time.”
Pregnancy registries as a source of safety information
Pregnancy exposure information can originate through different mechanisms, including routine pharmacovigilance reporting and structured pregnancy follow-up activities.
A registry provides an opportunity to collect information systematically rather than relying only on individual spontaneous reports. This can be particularly valuable when the objective is to understand pregnancy outcomes over time and to evaluate potential patterns across a population.
However, pregnancy registry data remain observational and should be interpreted appropriately when assessing potential associations between medicinal-product exposure and pregnancy outcomes
Pregnancy Registries in Clinical Research and Pharmacovigilance
Pregnancy registries sit at the intersection of clinical research and pharmacovigilance.
From a clinical perspective, they can provide information about treatment exposure and pregnancy outcomes in populations that may have limited representation in clinical trials.
From a pharmacovigilance perspective, they can contribute structured information to the ongoing safety evaluation of medicinal products.
Their value becomes particularly evident when registry data are combined with other evidence sources, allowing safety professionals to develop a more complete understanding of the potential risks associated with exposure during pregnancy.
Characteristics of pregnancy registries
A well-designed pregnancy registry should consider several important characteristics.
1. Inclusive enrollment criteria
Registries should generally be inclusive rather than unnecessarily exclusive, using comprehensive inclusion criteria.
A broad approach can help ensure that relevant pregnancy exposures and outcomes are captured rather than restricting enrollment to a narrowly defined group.
Importantly, although prospective enrollment is preferred, retrospective enrollment should not necessarily be discouraged. Retrospective information can still provide valuable evidence, although its retrospective nature should be considered when analysing and interpreting the data.
2. Solicited information
Information collected through an organised pregnancy registry is generally obtained through a structured follow-up activity rather than arising purely from unsolicited spontaneous reporting.
This distinction is important in pharmacovigilance because the source and method of collection can influence how the information is classified, processed, followed up, and assessed.
3. Prospective follow-up
Prospective enrollment and follow-up are generally preferred.
Following a pregnancy from exposure through its outcome allows information to be collected at different stages rather than relying solely on information available after the pregnancy has ended.
Nevertheless, retrospective enrollment may still provide useful information and can contribute to the overall evidence base when appropriately identified and analysed.
Why is it included as crucial source of report?
Pregnancy registries can provide information that may be difficult to obtain through conventional clinical trials or spontaneous reporting systems alone.
One important consideration is the design of the registry itself.
Registries designed to capture pregnant women with a particular disease or condition, rather than being limited exclusively to exposure to a single medicinal product, may provide broader opportunities to evaluate treatment patterns and pregnancy outcomes.
Such registries can support longitudinal assessment of:
- Treatment exposure during pregnancy
- Changes or switches between medicinal products
- Different treatment patterns
- Pregnancy outcomes
- To collect safety information
- Outcomes among exposed and, where available, unexposed populations
- Longer-term outcomes in neonates and infants
This broader approach may also allow comparisons between different treatment exposures and pregnancy outcomes.
In exceptional circumstances, however, a medicinal-product-specific pregnancy registry may be appropriate when the safety question or characteristics of the product justify such an approach.
Using Existing Pregnancy Registries and Databases
Developing a completely new registry is not always necessary.
Where suitable existing pregnancy registries or databases are available, their use can provide several advantages, including:
- Existing infrastructure for data collection
- Established follow-up procedures
- Availability of comparator groups
- Opportunities for longer-term follow-up
- More efficient data collection and analysis
- Reduced duplication of existing efforts
Using established data sources may therefore improve the feasibility and efficiency of pregnancy safety studies.
Key Takeaways
Pregnancy registries can play an important role in understanding medicinal-product safety during pregnancy.
The key points are:
- Pregnancy registries systematically collect information on pregnancy exposure and outcomes.
- They complement routine pharmacovigilance reporting mechanisms.
- Prospective enrollment is generally preferred, although retrospective information can still be valuable.
- Registries should generally use comprehensive and inclusive enrollment criteria.
- Disease-based registries may provide broader information than product-specific registries in some circumstances.
- Existing pregnancy registries and databases can improve efficiency and provide opportunities for comparator and long-term follow-up data.
- Hybrid approaches can combine product-specific information with existing public or healthcare data sources.
- Follow-up may extend beyond delivery to neonates and infants.
- Breastfed infants may also be relevant when exposure through breast milk is possible.
- Registry information can contribute to the identification and evaluation of potential safety signals.
- Pregnancy registry findings should be interpreted alongside other clinical and pharmacovigilance evidence.
Conclusion
Pregnancy registries provide a structured approach to collecting and following information on medicinal-product exposure during pregnancy. Their longitudinal nature can provide valuable information on pregnancy outcomes and, where appropriate, longer-term neonatal and infant outcomes.
Rather than replacing routine pharmacovigilance systems, pregnancy registries complement existing safety data sources and can strengthen the overall evidence base for evaluating medicinal-product safety in pregnancy.
The most effective approach depends on the safety question, the medicinal product, the population being studied, available databases and registries, and the required duration of follow-up. Careful registry design, comprehensive enrollment, appropriate follow-up, and robust analysis are therefore essential for generating meaningful pregnancy safety evidence.
For pharmacovigilance professionals, understanding how pregnancy registries work—and how their information fits into the broader safety surveillance framework—is an important part of evaluating medicinal-product safety throughout the product lifecycle.
