<i>Prostaglandin-endoperoxide synthase</i> 2 (<i>PTGS2</i>) and <i>PGF2α-receptor</i> (<i>PTGFR</i>) mRNA expressions were compared between primary UI (PUI) and obstructive dystocia (OD) samples in isolated parturient myometrium. Here, PTGFR is linked to osteochondritis dissecans.