Passage: It has important effects in labour (softening the cervix and causing uterine contraction) and also stimulates osteoblasts to release factors that stimulate bone resorption by osteoclasts.  PGE2 is also the prostaglandin that ultimately induces fever. It is also implicated in duct-dependent congenital heart diseases and is used in infusion in order to open the duct although PGE1 is more commonly used.

Question: What is the most important effect it has in labor?
softening the cervix and causing uterine contraction