20-30% of fetuses are lost 15-30 days into gestation in pigs, and an additional 10-15% are lost in days 50-70. In mammals an uterine leukocyte (uNK) recruits during endometrial decidualization, and expand in early gestation, then decline mid-gestation. For humans and mice uNK produces HIF-1α, VEGF, and PIGF. In pigs, uNK is first detected at day 12, and is triggered by the attachment of conseptuses since the endometrium does not decidualize. This study aimed to determine if leukocytes like uNK can have a proangiogenetic result in mid-gestation, and to trace the difference between day 20 to 50. Proinflammatory cytokines (IFN-γ
and TNF-α) transcription levels were analyzed at gestation day 20 and 50, as these have been present when fetuses have been aborted. The transcription levels were compared between peri-implantation and mid-gestation pregnancy failures. The results found pig leukocytes produce VEGF and PlGF, like other mammals. PIGF aids in uNK maturation, which produce VEGF, and VEGF levels were higher at day 50 than 20 in healthy cells. Pregnancy failures corresponded with low levels of VEGF and HIF-1α transcription, but not with low levels of PIGF. Healthy sites transcribed IFN-γ
and TNF-α, a day 20 arrest had higher IFN-γ
transcripts, and day 50 arrests had a higher level of TNF-α. The implication of the results is that pig leukocytes play a role in angiogenesis until mid-gestation.