Trasferimento di embrioni ottenuti mediante tecniche di riproduzione assistita nella specie ovina: anomalie morfologiche e vascolari durante la fase iniziale della gravidanza

Fetal growth depends on the development of a normal placenta and often pregnancies obtained from ARTs showplacental defects, owed to vascular anomalies. SCNT and monoparental embryos provide important models for studyingplacental insufficiency. We have used these models for evaluating their morphological and vascular features from 20thto 23rd days of pregnancy, critical time for early vascularity. Maternal caruncles, chorioallantoic membranes and, ifpresent, embryos from natural mating (n=5), after IVF (n=7) and after transfer of in vitro activated parthenogenotes(IVA, n=5) have been collected. IVA embryos showed higher resorption (80% IVA, 42,8% IVF, 20% CTR) andreduced development than IVF and controls. The histological analysis have demonstrated a normal caruncolardevelopment, but high degenerative changes in the IVA fetal membranes. The vascular parameters evaluated (by meansof quantitative analysis on PCNA labelled sections) were: capillary area density (CAD), capillary number density(CND), capillary surface density (CSD). Caruncles obtained from natural mating showed higher CAD, CND and CSDthan IVF and IVA (p < 0.05). This study demonstrates that the placental vascular development is compromised in theearly pregnancy obtained from ARTs and should be considered as important factor for related high rate of embryonaldeath.[...]