After IVF: reason for 'no sex' warning for 12 wks?

Jenn

It seems like the majority of posts I've seen on the guidance after a BFP is no sex for the first trimester. Anyone know why? General guidance is that it's safe, but I know us IVFers are 'extra special' (read: high risk🙄). Just not sure the biological reasoning since orgasm contractions are different than labor contractions in the uterus.

Any insight or experience one way or the other?