My preggie book says that 90% of pregnancies are fine past 7 weeks I think (it could be 6??) so I would say many of the m/c he is talking about are those 3-5 weekers that just dont stick.

He is a fascinating presenter. I've seen one he did on people and reproduction and it talked about human scent, and it makes us choose our "baby-partners". Apparently someone with an attractive scent has less similar genetic makeup to ourself, therefore would provide the strongest offspring.
Someone who we find smells bad has a very simlar genetic code to ourselves, thus the babies wouldn't have a wide spectrum of healthyness.
Isn't that fascinating??
Fi