Jason Biggs' Wife Jenny Mollen -- Wanna See My Placenta?

Jason Biggs' wife just dished out a healthy dose of reality to potential parents ... by tweeting a pic of her placenta in all its bloody glory.

Biggs' wife Jenny Mollen popped out Sid Biggs Saturday afternoon ... and then shared the placenta photo with the caption, "Hope I'm not 'over sharing' but there's no denying my placenta looks super hot and thin in this pic."

The new mom says she wanted to turn her nutrition sac into a pill ... but docs advised against it -- so now she's saving it for a cake topper on Sid's 1st b-day.