I have just read this article Here regarding cord blood and thought i would let people know what happened for me as i was involved in a clinical trial and I am rhesus negative.

I asked for the cord to be left unclamped until it finished pulsating. I had asked my midwife if this would be possible with the amount needed for the clinical trial and the blood tests to see whether i would need anti-D. You will be pleased to know that this was possible and there was plenty of blood for the trial and the test. I thought I would share this info as it was something I was concerned about being able to do as i thought that once the cord stopped pulsating there would be no blood left in it. so Rh-ve girls, yes you can let it stop pulsating and still have the tests to see if you need another shot of anti-D