Real-world experience of adding placental histopathology studies into perinatal clinical trials

Addition of placental histopathology studies to obstetric trials is likely to be cost-effective and may reveal structural changes suggestive of functional dysfunction to explain the success or failure of a clinical intervention. We share our recent experience in adding placental pathological examination to two clinical trials, retrospectively in one and at the outset in the other, so that other clinical trial investigators may benefit from it. The practical issues can be summarised as being regulatory and ethical, operational and reporting. Prospective inclusion of placental pathological examination as part of a clinical trial protocol is easier than retrospective, and is facilitated by fully-costed funding.