Pathology of the Placenta in Singletons after Assisted Reproductive Technology Compared to Singletons after Spontaneous Conception: A Systematic Review.

Background: We reviewed the literature comparing the pathological characteristics of singleton births conceived after assisted reproductive technology (ART) with those after spontaneous conception. Methods: We reviewed PubMed, EMBASE, Ovid MEDLINE, Google Scopus, Scholar, Cochrane Central Register of Controlled Trials and the Web of Science for the previous 10 years, up to November 2022. Results: Four eligible studies included 3445 placentas, 806 after ART (IVF/ICSI). Placentas after ART differed in frequency of retroplacental and marginal hematomas ( p  = 0.04), increased thickness ( p  = 0.02), higher overall occurrences of vascular and anatomical pathology ( p  < 0.001) and more frequent marginal ( p  = 0.001) and membranous ( p  = 0.02) umbilical cord insertion than placentas from non-ART pregnancies. Conclusion: Further research is needed to determine the extent to which these placental changes in ART pregnancies alter its function and pregnancy outcome.