Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Health & Pregnancy

Font Size

Fetal Ultrasound

Fetal ultrasound is a test done during pregnancy that uses reflected sound waves to produce a picture of a fetus camera.gif, 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.

Pregnancy: Should I Have an Early Fetal Ultrasound?

A combination of screening tests using ultrasound may be done in the first trimester to look for birth defects, such as Down syndrome. The first-trimester screening 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.

Health Tools

Health Tools help you make wise health decisions or take action to improve your health.

Why It Is Done

Fetal ultrasound camera.gif is done to learn about the health of the fetus. Different information is gained at different times (trimesters) during your pregnancy.

  • 1st-trimester fetal ultrasound is done to:
    • Determine how your pregnancy is progressing.
    • Find out if you are pregnant with more than 1 fetus.
    • Estimate the age of the fetus (gestational age).
    • Estimate the risk of a chromosome defect, such as Down syndrome.
    • Check for birth defects that affect the brain or spinal cord.
  • 2nd-trimester fetal ultrasound is done to:
    • Estimate the age of the fetus (gestational age).
    • Look at the size and position of the fetus, placenta, and amniotic fluid.
    • Determine the position of the fetus, umbilical cord, and the placenta during a procedure, such as an amniocentesis camera.gif or umbilical cord blood sampling.
    • Detect major birth defects, such as a neural tube defect or heart problems.
  • 3rd-trimester fetal ultrasound is done to:
    • Make sure that a fetus is alive and moving.
    • Look at the size and position of the fetus, placenta, and amniotic fluid.

Transvaginal ultrasound is generally done early in a pregnancy to determine fetal age or to detect a suspected ectopic pregnancy camera.gif. It is occasionally done late in pregnancy to determine the location of the placenta or in a high-risk pregnancy to monitor the length of the cervix camera.gif.

1 | 2 | 3 | 4 | 5

WebMD Medical Reference from Healthwise

Last Updated: September 09, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

Pregnancy Week-By-Week Newsletter

Delivered right to your inbox, get pictures and facts on
what to expect each week of your pregnancy.

Today on WebMD

hand circling date on calendar
Track your most fertile days.
woman looking at ultrasound
Week-by-week pregnancy guide.
Pretty pregnant woman timing contaction pains
The signs to watch out for.
pregnant woman in hospital
Are there ways to do it naturally?
slideshow fetal development
pregnancy first trimester warning signs
What Causes Bipolar
Woman trying on dress in store
pregnant woman
Close up on eyes of baby breastfeeding
healthtool pregnancy calendar
eddleman prepare your body pregnancy