SonoGraphy

Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Although this limit varies from person to person, it is approximately 20 kilohertz (20,000 hertz) in healthy, young adults and thus, 20 kHz serves as a useful lower limit in describing ultrasound. The production of ultrasound is used in many different fields, typically to penetrate a medium and measure the reflection signature or supply focused energy. The reflection signature can reveal details about the inner structure of the medium. The most well known application of this technique is its use in sonography to produce pictures of fetuses in the human womb.

Sonography is used routinely in obstetric appointments during pregnancy, but the FDA discourages its use for non-medical purposes such as fetal keepsake videos and photos, even though it is the same technology used in hospitals.

Obstetric ultrasound is primarily used to:

• Date the pregnancy (gestational age)


• Confirm fetal viability


• Determine location of fetus, intrauterine vs ectopic


• Check the location of the placenta in relation to the cervix


• Check for the number of fetuses (multiple pregnancy)


• Check for major physical abnormalities.


• Assess fetal growth (for evidence of intrauterine growth restriction (IUGR))


• Check for fetal movement and heartbeat.


• Determine the sex of the baby