lisa dixon is a technician, charging around $500 for the at-home viewing experience. >> it's entertainment purposes only, so i do no diagnostics. >> reporter: critics worry extra ultrasounds may pose unnecessary risks. >> just because it's safe in medicine doesn't mean it should be done excessively or without proper medical indication. >> usually the third or fourth one, and there's no risk in that. there's no proven risk in that. >> reporter: the smiths already knew they were having a boy. and it was finally time to show him off. >> there's the heart beat. >> reporter: and grandma, overjoyed to see her grandson for the very first one. >> i'm very happy. >> reporter: abbie boudreau, abc news, los angeles. >> oh, that's just some taco bell. don't worry.