This article examines prenatal ultrasound use in the United States between 1995 and 2006. There is no professional consensus on the appropriate use of ultrasounds during pregnancies considered low-risk, and little is known about national trends of prenatal ultrasound use. The authors analyzed data from the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey from 1995-2000, 2005 and 2006. Information from 2001-2004 was not available on prenatal ultrasound use.

Key Findings:

• The average number of ultrasounds per pregnancy increased from 1.5 between 1995 and 1997 to 2.7 between 2005 and 2006.
• The average number of ultrasounds per low-risk pregnancy increased from 1.3 to 2.1, while the average number of ultrasounds per high-risk pregnancy increased from 2.2 to 4.2.
• The average number of ultrasounds per pregnancy varied by age, risk status, race and geographical region. In general, White women received more ultrasounds on average than Black women. Women over 35 were also likely to have more ultrasounds during pregnancy. There was no group of women, categorized by race, region, age, or risk, who did not receive at least one ultrasound on average during pregnancy.
• In the 2005-2006 sample, women in the northeast received two more ultrasounds on average per pregnancy than women in the south.

Women are receiving more ultrasounds per pregnancy now than in the 1990s, resulting in significant medical costs. Because assessing the medical benefits of multiple ultrasounds is complex, there is no clear consensus as to whether the benefit from increased numbers of ultrasounds outweighs the cost.