From what i have read - to delay by two mins is to receive 80% of the blood/iron/nutrient stores from the placenta.
From there it can vary tp up to twenty mins to stop pulsating. Some doctors/hospitals dont like to delay clamping because they think it can cause jaundice in the baby (i think) - BUT the extra value your bub would get out of delaying clamping is much better for a couple of hours spent under phototherapy.
I'll see if i can find the article i read...

Here it is Sammiejane - i found it very useful because i didnt know anything about delaying cord clamping.
https://www.bellybelly.com.au/birth/...-cord-clamping