Priority Setting Partnership on Placental Pathology: Consensus recommendations for placental research

The placenta supports the metabolic and respiratory requirements of the fetus. Placental disorders, caused by various pathophysiological mechanisms, may result in adverse pregnancy and neonatal outcomes. Knowledge gaps remain in the understanding, reporting and interpretation of placental pathology relating to clinical conditions. This project aimed to collaboratively identify the most important unanswered research questions related to placental pathology.

An international Priority Setting Partnership (PSP) was conducted, involving (perinatal) pathologists, obstetricians, paediatrician-neonatologists, midwives, and scientists with expertise in placental pathology. In the first survey, participants identified their three most important unanswered research questions. Afterwards literature was reviewed for evidence on the proposed questions. In a second survey, participants ranked the most important questions from an initial long-list. The top-ranked questions were then discussed and finalized in a 1-h online consensus workshop.

Ninety participants completed the first survey. The majority of stakeholders were perinatal pathologists (n = 39 (43.3 %) and most were based in Europe (n = 43 (47.8 %). 270 questions were submitted; after review, these were subdivided into 32 overarching questions. The second ranking survey was completed by 53 participants. Twenty-five participants attended the online workshop, which reached consensus on the top 10. The questions focus, among others, on causes, recurrence risk, consistency of reporting, diagnosing tools and potential use of artificial intelligence.

Following this international PSP, the top 10 prioritized research questions on placental pathology have been identified. This will inform the research agenda for funders and policy-makers, and is intended to improve care for patients suffering from placental insufficiency.