The journal, Obstetrics and Gynecology, estimated that over half of all pregnant women in 1990 had undergone diagnostic ultrasound, yet research published in the New England Journal of Medicine suggest that 80 percent of all pregnant women are very low risk and do not need ultrasounds. The unnecessary ultrasounds cost about $1 Billion per year.

Any woman who is told she needs an ultrasound should ask about the potential benefits of the test and the risks of the procedure. She should ask if the results of the ultrasound will affect her care she would otherwise receive and how. If the result of the ultrasound will not affect her care, she may question the need for the test at all. Only after being completely informed about the need for the test, the benefits, and the risks, should she sign a consent for the procedure.

USES OF ULTRASOUND

According to the ACOG patient education flier, "Ultrasound is not necessary for every woman or in every pregnancy." It is, however, being used more often as a standard procedure for every pregnant woman. Some common uses include diagnosing and detecting uterine or ectopic pregnancy, noting pelvic inflammatory disease, cysts, tumors uterine cancer, endometriosis and congenital abnormalities.

Ultrasound may compare fetal age and weight, note the placement of the placenta, amount of amniotic fluid that is present and diagnose certain birth defects such as neural tube defects. Ultrasound is used during an amniocentesis to verify the baby's position to be sure that the needle is placed properly. Some physicians use ultrasound for estimating the fetal weight. This is not a very accurate measurement unless numerous criteria and scans are checked. Head circumference is one measurement. However, incases of gestational diabetes, it is inaccurate because these babies gain the additional weight on their bodies only.

Ultrasounds are frequently used to date pregnancies. According to Otto and Platt, 1991, in the first trimester the error range is +5 days, in the second trimester it increases to +8 days and if done in the final trimester it is +22 days.