Sarah Buckley's article on "Third Stage - Leaving Well Enough Alone" helped me get my head around this.

Basically, the natural oxytocin your body produces does the job of syntocinon (which is artificial oxytocin). Oxytocin first causes your uterus to contract to push out the baby. After the baby is born, oxytocin causes the uterus to contract and expel the placenta - the contracting clamps off the blood vessels so you don't haemorrhage.

Oxytocin is pretty amazing, it's the "Love Hormone" that is responsible for orgasm as well as birth! It is also responsible for the let-down reflex when breastfeeding. So the things that help those activities, likewise help the flow of oxytocin after birth so that your uterus clamps down effectively and blood loss in minimized. Oxytocin also enlarges the blood vessels on your chest - creating a natural heating pad for the baby to lie on and stay warm. That's one reason why they encourage skin-to-skin cuddling right after birth. Then the baby, snuggled up warm with mum, smells this heavenly smell and gradually becomes interested in the nipple. The nuzzling increases the release of the oxytocin. And that helps the placenta detach, and the uterus to involute and expel the placenta. (That's why "nipple stimuation" is suggested as one way to get labour going - it stimulates the release of oxytocin). Oxytocin, the "feel good hormone" is the magic behind all of this!

A quiet, warm room, with dim lighting and gentle voices also helps optimize the release of natural oxytocin.

My understanding is that with gentle, patient care, if all the above is unfolding naturally, there is no need for artificial syntocinon. I see no need to use it routinely or prophylactically - I would prefer that it is reserved to use only when actually indicated - for example, if my blood loss was too much for any reason.

It is not necessary to clamp the cord or pull on the cord (even gently) during a physiological third stage. Sometimes kneeling up, or sitting on the toilet or giving a cough can be enough to gently birth the placenta. Some parents don't cut the cord until after the placenta is out, and some don't cut the cord at all (Lotus Birth). These are all options.