I've Noticed This Twice Today So Far... C'Mon MSNBC...

[jeff47]

9. It's about proximity and also what the waves pass through.

Most of the time, the trans-vaginal is closer.

But there also isn't a wide variety of tissue with differing density between the vagina and the uterus. There is between the "belly" and the uterus...which is one of the reasons pre-natal "belly" ultrasounds are usually done with a full bladder.

What I'm saying is the 'belly' ultrasounds would produce an indistinct smudge at that gestation. While transvaginal lets you actually see the fetus.

And yes, I'm male. Doesn't mean I'm clueless. Aside from what people learn in biology if they pay attention, my wife had to have a transvaginal ultrasound early in her pregnancy when they couldn't resolve the fetus through her belly. The smudge on the screen that may-or-may-not be a baby on the 'belly' ultrasound became quite distinct transvaginally.