Interestingly enough; That means Deibu can't have sex again, like *ever*. What happens if you shake a yukkuri when it's pregnant? Given the mamu-mamu and peni-peni are the same organ turned inside-out...Would that mean instant miscarriage?
I'm not sure this would work, I've never seen a mother be able to stop there child from being born before. I can also see this ending like that one comic where a reimu pretends to be pregnant and than get real fat before her husband leaves her to star to death in there house because she became to big to leave.
Another one is from True Happiness where mother Reimu tries to runaway from anon to protect her only child(or children) inside of her but when she's going to give birth, she can't hold it anymore no matter how hard she tries.