I stumbled across this a few days ago: about 10 years ago there was a study that suggested that women who swallow semen are quite substantially less likely to develop pre-eclampsia (a complication of pregnancy involving high blood pressure). And it would appear that the evidence in favour of this suggestion has been mounting. anyway, if anyone out there is feeling a bit intellectual, here's the original paper.
Another reason to get your girl to take a facial and then swallow.
:-)
The final sentence of the paper says it all.