Fetal Ultrasound

Obstetric Ultrasound, Pregnancy Ultrasound, Sonogram, Fetal, Ultrasound, Fetal, Ultrasound, Obstetric, Ultrasound, Pregnancy

Test Overview

Fetal ultrasound is a test done during pregnancy that uses reflected sound waves to produce a picture of a fetus, the organ that nourishes the fetus (placenta), and the liquid that surrounds the fetus (amniotic fluid). The picture is displayed on a TV screen and may be in black and white or in color. The pictures are also called a sonogram, echogram, or scan, and they may be saved as part of your baby's record.

Fetal ultrasound is the safest way to check for problems and get information about your fetus, such as its size and position. It does not use X-rays or other types of radiation that may harm your fetus. It can be done as early as the 5th week of pregnancy. The sex of your fetus can sometimes be determined by about the 18th week of pregnancy. For more information, see:

Should I have an early fetal ultrasound?

A combination of screening tests using ultrasound may be done in the first trimester to look for Down syndrome. The integrated test uses an ultrasound measurement of the thickness of the skin at the back of the baby's neck (nuchal translucency) and the blood levels of free beta-HCG and a protein called pregnancy-associated plasma protein A (PAPP-A) to check for problems.

	Go to top of page	Go to next section
Author:	Maria G. Essig, MS, ELS	Last Updated: June 28, 2007
Medical Review:	Adam Husney, MD - Family Medicine Joy Melnikow, MD, MPH - Family Medicine Deborah A. Penava, BA, MD, FRCSC, MPH - Obstetrics and Gynecology
© 1995-2009 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.