


The first fetal ultrasound is usually done during the first trimester to confirm and date the pregnancy. If your pregnancy remains uncomplicated, the next ultrasound is typically offered during the second trimester, when anatomic details are visible. If your baby's health needs to be monitored more closely, additional ultrasounds might be recommended.

First trimester ultrasound examination is done to evaluate the presence, size, number and location of the pregnancy. Ultrasound can also be used for first-trimester sonographic genetic screening, as well as screening for any abnormalities of your uterus or cervix.






If your health care provider doesn't suggest a fetal ultrasound but you'd like the reassurance an ultrasound can provide, share your wishes with your provider so that you can work together to determine what's best for you and your baby.

Diagnostic ultrasound has been used during pregnancy for many years and is generally considered safe when used appropriately. The lowest amount of ultrasound energy that provides an accurate assessment should be used. Obstetric providers and ultrasonographers are trained in appropriate use of ultrasound energy.

Ultrasound should be requested only by a doctor or licensed health care provider for medical reasons. The use of fetal ultrasound solely to create keepsake photos or videos isn't recommended.




There are two main types of fetal ultrasound exams:

  • Transvaginal ultrasound. With this type of fetal ultrasound, a wandlike transducer is placed in your vagina to send out sound waves and gather the reflections. Transvaginal ultrasounds are used most often during early pregnancy, when the uterus and fallopian tubes are closer to the vagina than to the abdominal surface.
  • Transabdominal ultrasound. A transabdominal fetal ultrasound is done by moving a transducer — a small plastic device that sends and receives sound waves — over your abdomen. This type of fetal ultrasound is usually used during the later part of your pregnancy.

Various other types of transabdominal ultrasounds are available, including:

  • Specialized sonographic evaluation. Specialized examination might be needed in specific circumstances, such as when a fetal abnormality is known or suspected. In this situation, a more detailed evaluation can provide additional information about the abnormality.
  • Doppler ultrasound. A Doppler ultrasound measures slight changes in the ultrasound waves as they bounce off moving objects, such as blood cells. A Doppler ultrasound can provide details about a baby's blood flow.
  • Fetal echocardiography. This type of fetal ultrasound provides a detailed picture of a baby's heart. It might be used to confirm or rule out a congenital heart defect.

During the exam

During a transabdominal fetal ultrasound, you'll recline on an exam table and expose your abdomen. Your health care provider or technician will apply a special gel to your abdomen. This will improve the conduction of sound waves and eliminate air between your skin and the transducer — the small plastic device that sends out sound waves and receives those that bounce back.

Your health care provider or technician will move the transducer back and forth over your abdomen. The sound waves reflected off your bones and other tissues will be converted into images on a monitor.



The procedure for other types of fetal ultrasound exams is similar. If you're having a transvaginal ultrasound, however, you'll be asked to change into a hospital gown or undress from the waist down. You'll recline on an exam table and place your feet in stirrups. Your health care provider or technician will place a lubricated transducer in your vagina rather than moving it across your abdomen.

After the exam



Sept. 19, 2015