Yes, we know you are probably already peeing like crazy and how can you possibly drink anymore?!?!
Drinking water is not only healthy for mom and baby, it also helps getting great ultrasound pictures. The fluid around the baby helps the ultrasound waves obtain clearer pictures.
Baby's face can be up against the wall of the uterus or up against the placenta, causing artifact during 3D ultrasounds. Drinking extra water (AT LEAST 64 oz) a week before helps improve the amniotic fluid levels.