Over the Belly
The pose above could work as a cute "can I see my feet?" photograph. However, that is not the intent. Rather, this image is meant to be photographed from below.
This is a simple, fun, and easy to accomplish. You are essentially choosing between two focal points, the mom-to-be's face or her pregnant belly. Each can work as well as the other. A shallow depth of field will clarify your choice, a wide depth of field will keep everything in focus.
Depending on the exact angle, the mom-to-be's expression, the style of light and the size and shape of the belly, you can have a photo which is sweet, funny, artistic or even startling.
