Definition of Pregnancy ultrasound

Pregnancy ultrasound: Creating an image of the developing fetus within the uterus by means of measuring the vibrations returned when a device emits high-frequency sound waves.

Ultrasound imaging has been done during pregnancy for over three decades. It has proven to be a very useful, safe, and very effective diagnostic procedure. Ultrasound may be performed in early pregnancy to:

• establish whether a normal pregnancy is present
• confirm gestational age
• identify cases of multiple gestation
• determine fetal heartbeat
• Later on in pregnancy, ultrasound can be used to look for any developmental or other problems in the fetus, to measure the size, growth, and position of the fetus, to determine the gender of the fetus, and to check for abnormalities of the placenta, uterus, or amniotic fluid.

A number of epidemiological studies of pregnancy ultrasound exposure have been done to look at its safety. These include studies with a highly sophisticated research design (such as case-control and prospective randomized control studies).

The great majority of the studies have been completely negative. Although an occasional study has found diagnostic ultrasound to be associated with one or another effect (such as low birth weight, delayed speech, or an increased incidence of left-handedness), these findings have never been duplicated (except for low birth weight) in any other study.

In spite of literally millions of examinations, there is no verified documented evidence of any adverse effects caused by exposure of the embryo or fetus to diagnostic ultrasound. (Reference: Ziskin MC. Intrauterine effects of ultrasound: Human epidemiology. Teratology 59:252-260, 1999.)

There is thus no convincing evidence for any danger from diagnostic ultrasound during pregnancy.

Pregnancy ultrasound is also referred to as prenatal ultrasound.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=9509
Last Editorial Review: 8/16/2007