Umbilical Vein Injection for 3rd Stage?

The 3rd stage of labor is the time from child's birth to delivery of the placenta. Delayed placental separation and expulsion is a potentially life-threatening event because it hinders expected postpartum uterine contraction, which can lead to PPH. The concept of umbilical vein injection of a variety of substances (saline, pitocin, plasma expanders) is nothing new. It was first described in the 1930s! This had found new life in the 1980s and 1990s but soon thereafter again fell into ambiguity. What is the theorized MOA of this intervention? Does oxytocin injection into the umbilical vein help prevent PPH? Is this an effective management option in the 3rd stage? We will walk down history's timelime and find out. We will also summarize the data of 2 Cochrane Reviews that have twice looked at this technique, with the last published report in 2021. Thank you Haley for the podcast topic suggestion!