“…The angiogenesis process depends on the expression of angiogenic factors such as vascular endothelial growth factor A (VEGFA) (Karaman et al, 2018; Simons et al, 2016; Vonnahme et al, 2001), angiopoietins (ANGPT1‐ANGPT2) (Wang & Lash, 2017) and basic fibroblast growth factor (bFGF or FGF2) (Welter et al, 2004) that act by binding to specific receptors such as Flt‐1 (VEGFR1) and KDR (VEGFR2 or Flk‐1), TEK2, FGFR1‐R2 respectively. While many studies have provided evidence for the differential expression of pro‐angiogenic growth factors and blood vessels development in the porcine placenta, the exact cause of spontaneous fetal loss is uncertain (Charnock‐Jones et al, 2001; Fiorimanti et al, 2022; Fiorimanti, Cristofolini, et al, 2018; Fiorimanti, Rabaglino, et al, 2018; García‐Fernández et al, 2015; Guimarães et al, 2017; Sanchis et al, 2015; Stenhouse et al, 2019; Vonnahme & Ford, 2004). During early gestation in pigs, significant morphological changes occur at the maternal–chorioallantoic interface, as a greater increase in placenta weight occurs between 37 and 42 days of gestation (Wright et al, 2016).…”