Like many advances in medicine, ultrasound was not "discovered" for its medical utility. Ultrasound is modification of sonar, or acoustic (sound) waves to aid in the imaging of the human body. It allows physicians to "see" the reflection of the sound waves as images of internal structures. It has moved beyond its original use in obstetrics for basic diagnosis of pregnancy and fetal life to detailed fetal "physical examinations" and utility in invasive procedures to the fetus in the attempt to prevent fetal death or other intrauterine complications. Uses for ultrasound outside of obstetrics have also grown since its first use. In some practices it is frequently a part of routine examinations as well as being used as a tool for diagnosis in non-gynecologic areas of women’s health care.

Ultrasound is now a "real time" process. This means that a picture is rapidly generated by the computer as the acoustic information comes back to it. There is essentially no delay and the operator can alter the image with positioning of the probe to yield an optimal examination of the organ in question. The images of the fetus produced by ultrasound can be used not only to evaluate the presence of birth defects, but can be used to monitor fetal activity and use this information to assist in the determination of the fetal well-being. The most recent advance in ultrasound technology now allows for three dimensional imaging of fetal surface structures, such as the face, when adequate amounts of amniotic fluid are present.

For many years, gynecologists have used ultrasound to augment pelvic examinations. Evaluation of the female pelvis has evolved most frequently in a dual imaging approach. The appearance of the pelvic organs, uterus, and ovaries are evaluated through the abdominal wall and through the use of a probe placed in the vagina for closer, less distorted images. Benign uterine tumors, called fibroids, are frequently identified on examination when the uterus is enlarged and irregular in shape. These fibroids can be evaluated for size and sometimes number by ultrasound. The instillation of small amounts of saline into the uterine cavity has the advantage of allowing visualization of structures in the cavity that may be the cause of abnormal bleeding. The contour of the ovaries can be evaluated and cystic structures in the ovary can be characterized. Information from ultrasound examination can assist in the diagnosis of benign and malignant tumors of the ovaries.

During evaluations for infertility, ultrasound has become essential for monitoring the ovary for the effects of ovulation induction agents. Ultrasound guidance is used sometimes daily to monitor the ovarian response to these medications. It is also used to assist in procedures surrounding in-vitro fertilization. Monitoring of early pregnancy by the infertility expert or in any pregnancy at risk for early loss allows for early detection of a successful or failed pregnancy and ectopic pregnancy.

Outside of female-specific problems, ultrasound has also become widespread in its ability to evaluate organs in a non-invasive fashion. It is used to evaluate the heart and its valves. Abnormalities of blood vessels, such as blood clots or arterial plaques that place people at risk for strokes can be evaluated without the need for dyes that can place patients at risk for allergic reactions. Although much focus is on the view into the womb that is possible with ultrasound, its use in other areas of women’s health is widespread. It has advanced our ability to evaluate without surgery, localize areas that require biopsy and define lesions to allow for refined surgical techniques. It has come a long way since its start in the science of sonar.