The cytokine Prokineticin-1 in preterm labor with and without intra-amniotic inflammation.

Prokineticin 1 (PROK1), known as endocrine gland-derived endothelial growth factor (EG-VEGF), is a key regulator of pregnancy, playing various roles from implantation to birth. We have shown that maternal serum concentrations of PROK1 are highest during the first trimester and are elevated in pregnancy complications such as spontaneous preterm birth (sPTB). Additionally, PROK1 is described as being largely expressed by the chorion in fetal membranes, suggesting its presence in amniotic fluid. Despite these findings, no information is available about PROK1 concentrations in the amniotic fluid, nor concerning its evolution in the context of spontaneous preterm labor with or without infection. PROK1 concentrations were measured in amniotic fluid from patients with spontaneous preterm labor (n=45) and from women at term without sPTB (n=30). Our findings revealed that PROK1 concentrations were, i) significantly elevated in preterm labor patients compared to term laboring controls; ii) higher in spontaneous preterm labor patients with intra-amniotic infection compared to those without infection, and iii) not affected by the process of labor at term. This study provides the first comprehensive characterization of PROK1 concentrations in amniotic fluid, highlighting its potential involvement in spontaneous preterm labor, with or without infection.