I've said pregnancy is a public private affair.
I've said pregnancy is a lonely affair.
Pregnancy is also a very intimate affair between you and your fetus.
Seriously, this is pretty much as close as close can be.
You and your offspring spend 10 months together and everything you experience, he/she experiences.
Every emotion she/he experiences.
It's pretty close, closer than a spouse can be.
It's comforting to know this bond is there.
It also reminds you that your responsibilities as a parent begin long before you even meet face to face.