A novel hysteroscopic technique for the accurate biopsy of decidua parietalis and basalis

BackgroundDiscrepancies in the results from studies of early events in human trophoblast invasion of decidua have been acknowledged and are attributed largely to deficiencies in the accuracy of sampling of the decidual tissue used in the research. We describe a novel technique of biopsy of decidua parietalis and basalis that overcomes the issue of accuracy of site of the biopsy.Methods & results:The technique is applicable to pregnancies undergoing first trimester surgical termination. Following cervical dilatation, a rigid hysteroscope is introduced into the cervical canal. The pressure of the saline distending medium shears the membranes of the gestation sac away from the decidua parietalis, leaving the pregnancy suspended at the site of the early placenta (the decidual basalis). Under direct vision a biopsy forceps is used to sample the decidua parietalis, and then the forceps is introduced beneath the gestation sac to sample the decidua basalis. Morphological and immunohistochemical studies have confirmed the accuracyof site and adequacy of the samples, with a 40% myometrial spiral artery success rate.ConclusionThis is a simple novel technique of decidual biopsy under direct vision which allows for high accuracy of the site of biopsy material, and therefore has the potential to revolutionize research on trophoblast-decidua interactions during the critical early stages of human pregnancy.