Intrinsically poor maternal adaptation to pregnancy and dysregulated processes have been postulated to occur as a consequence of an immune response to the feto-placental unit as "foreign" material. The aim of our study was to compare placental pathology and pregnancy outcomes of in vitro fertilization (IVF) pregnancies conceived by donor oocytes with those conceived by non-donor oocytes.
We conducted a retrospective, case-control study on 91 placentas from IVF pregnancies (36 from donor oocytes and 55 from non-donor cycles). All placentas were examined by a single pathologist for signs indicative of an immune response, including chronic villitis, chronic deciduitis, increased perivillous fibrin, ischemic change/infarction, decidual vasculopathy, increased syncytial knots, intervillous thrombi, and retroplacental hematomas.
Placentas from donor cycles were significantly more likely to demonstrate certain pathologic findings: chronic villitis (P<0.001), chronic deciduitis (P=0.034), increased perivillous fibrin (P=0.001), ischemic change/ infarction (P=0.001), and intervillous thrombi (P =0.008). There was no statistical significance with respect to decidual vasculopathy, increased syncytial knots, or retroplacental hematomas.
Pathologic evidence of an immune-mediated process is much more pronounced in donor oocyte IVF pregnancies compared to non-donor cycles. Clinical implications of these findings have yet to be determined.