[Pathomorphological features of the placentas and the placental sites after in vitro fertilization with a donor egg]

To identify the structural and immunohistochemical features of the placentas and the placental sites after in vitro fertilization (IVF) with a donor egg (surrogate motherhood).

Morphological and immunohistochemical studies were performed on the placental (a placental disk) and placental bed materials obtained after caesarean delivery. The investigation enrolled 26 patients whose pregnancy occurred with IVF with a donor egg according to the surrogacy (IVF-S) program. A comparison group included 13 patients whose pregnancy occurred after IVF with their own eggs. An immunohistochemical study was conducted on paraffin sections made from biopsy material; mouse antibodies to total cytokeratin (clone AE1/AE3, 'Dako'), HLA-DR (clone TAL.1B5, 'Dako'), and CD138 (clone MI15, 'Dako') were used as primary antibodies.

The histological examination of the placentas in the IVF-S group showed the high incidence of central ischemic heart attacks (69%), dissociated cotyledon development (61%), pathological villous immaturity mainly with the predominance of intermediate differentiated villi (46%), and massive perivillous fibrinoid deposition (73%). The obtained differences between with the study and comparison groups were significant (p<0.05). The IVF-S group was characterized by the development of lymphoplasmacytic deciduitis (1.23±0.4 and 0.5±0.3 scores). Examination of the placental site biopsy material in the IVF-S group revealed the following changes: remodeling of the spiral arteries was incomplete in more than 40% of cases, and in 30% of the spiral arteries had no gestational changes. In the comparison group, more than 90% of the spiral arteries were characterized by complete remodeling during pregnancy. There was also an increase in the count of multinucleated trophoblastic giant cells (104.56±4.21 and 65.67±14.45) and HLA-DR positive cells (41.86±5.32 and 29.00±1.87).

The placentas and the placental sites of the women whose pregnancy occurred with IVF-S are characterized by the development of high lyoplasmacytic deciduitis activity and pronounced placental immune alterations manifested by the high incidence of immune responses at the sites of the closest contact between maternal and fetal tissues. The placental bed exhibited defective spiral artery remodeling, development of chronic inflammatory lesions in the perivascular areas, and an increase in the counts of HLA-DR positive cells and multinucleated trophoblastic giant cells.