Introduction: There remains a significant gap in international data on pregnancy outcomes following kidney transplantation, posing a challenge for clinicians who lack extensive and universally accepted findings in this area. In our study, we sought to address this gap by comparing the methodologies of data collection and fundamental outcomes of pregnancies among female kidney transplant recipients (KTR) across three continents. Through this comparative analysis, we aim to provide valuable insights into the diverse approaches and outcomes associated with pregnancy post-kidney transplantation on a global scale.
Methods: Information was gathered from annual reports and published materials sourced from the Pregnancy After Renal Transplantation OUTcomes registry (PARTOUT) in the Netherlands, the Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) and the Transplant Pregnancy Registry International (TPRI) based in the United States with international coverage. Regular online meetings facilitated close collaboration among representatives from each registry. The comparison focused on carefully selected parameters to provide a comprehensive overview of both the key similarities and differences.
Results: Each registry utilized distinct methodologies for data collection. PARTOUT conducted its patient search via the National Organ Transplant Registry and consultations with health professionals. It included pregnant KTR in the Netherlands between 1971-2017 and the data was analyzed retrospectively. ANZDATA applies a voluntary reporting system that includes annual surveys regarding all KTR and all the pregnancy events registered since its formation (1960s). Since 2001 data is collected via paper surveys or online and in 2018 further data was added. TPRI follows a voluntary registration scheme since 1991, easily carried out via health providers or patient self-enrolment. Interviews with participants take place when enrolled, post delivery and then every two years to ensure consistent follow-up. Data collection differs among the registries, given it is tailored to each population. The evolution of each registry over time shows a rising trend in kidney transplant recipients that become pregnant and an efficient effort to tackle missing data by continuously reviewing and improving the methodology. Characteristics and basic outcomes are depicted in Table 1.
Conclusions: Similar outcome rates in KTR among the three registries accentuate that pregnancy in female KTR is attainable, but requires careful planning to mitigate the higher-risk. Acknowledging the registries’ strengths and limitations creates a clear picture of the similarities and differences; sustainability of databases is still challenging. Establishing datasets on a worldwide scale can increase the significance of observations, while identifying common core findings and factors defining the outcomes in this high risk patient group.