Semen Therapy Helps With Pregnancy
Correlation between oral sex and a low incidence of pre-eclampsia: a role for solubleHLA in seminal fluid ?
A dangerous condition of rising blood pressure that threatens the mother and risks miscarriage.
The mother’s immune system is fighting the baby because of the father’s DNA.
By swallowing his semen regularly her body accepts his DNA.
The same mechanism prepares her body to accept his sperm so she can get pregnant in the first place.
Wikipedia : Pre-eclampsia 7.7 Induction of paternal tolerance