You can think the concept of ancient Egyptian sonar isn’t insane if you like, but the Egyptians didn’t have sonar because it was developed in 1915 and you don’t use sonar to look at a baby in the womb, you use ultrasound. Sonar uses sound within the range of human hearing.
Also, it isn’t true.
So is there any science behind the ancient test? According to the National Institutes of Health, in 1963 researchers decided to try out the method. In a study published in the journal Medical History they found that wheat and barley watered with urine from men and non-pregnant women kept the grains from sprouting. But in about 70 percent of the cases, the urine from pregnant women did cause the grain to sprout. The test, however, did not accurately predict the sex of the children. It’s possible that increased estrogen levels in the urine could have helped stimulate the seeds.