According to research studies, ultrasounds pose no noticeable risks to the baby or mother. Ultrasounds are convenient, painless and give immediate and comprehensive results. They are an integral tool for pregnancy diagnostics and function by using high-frequency sound waves to image a developing baby, as well as the reproductive organs of the mother. They are much safer than x-rays because they use sound waves instead of radiation.
The only potential issue with ultrasounds is a false positive. That is, detecting a birth defect when it is not really there. Although follow-up examinations often show that the baby is healthy, these false alarms can understandably cause anxiety for the mother.
Usually doctors offer at least 2 scans during the course of a pregnancy, with the first mandatory scan performed at 8-14 weeks. This scan assesses when your baby is expected to be born and the second scan, at 18-21 weeks, assesses the physical condition of the baby. A pregnant woman has the right to refuse these procedures, though they are highly recommended to support the careful and accurate monitoring of pregnancy.