1800sonogram.com is a directory service of 3d 4d Ultrasound Centers in Colma for fetal imaging or pregnancy. If you are looking for Colma 3d 4d ultrasound centers to get your baby sonograms, use our directory to find a 3d 4d ultrasound center nearest to your home. Colma is a small town in San Mateo County, California. The population was 1,191 at the 2000 census. The town was founded as a necropolis in 1924. A large amount of Colma's land is dedicated to cemeteries. The town has a total area of 1.9 square miles, all of it land. Click here to view the ultrasound centers in Colma.