Don't know about research, but have seen both methods used in practice, I don't know our guidelines either. But would suggest it needs more reading around the incidence and management (yet another thing to do!)

I guess it would vary depending on the involution of the uterus, if it is well contracted then maternal effort may deliver it, if signs of separation are evident to negate the need for manual removal which we know if the more complex option of spinal, theatre , antibiotics etc.

I think I may see what I can find to help?

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