OB Ultrasound Protocol

An obstetric ultrasound is used to check on the fetus.

Common during pregnancy, obstetric ultrasounds are no cause for alarm. The number of ultrasounds a woman has during her pregnancy will depend on the doctor's assessment of the fetus' health and development.

Objective

The goal of an ultrasound is to confirm a pregnancy, assess fetal growth and well-being, check the amount of amniotic fluid, evaluate the position of the placenta and fetus and review the opening or shortening of the cervix.

Preparing for Ultrasound

Wear a loose, two-piece outfit to your ultrasound appointment and have a full bladder. Having a full bladder helps make the ultrasound image clearer by pushing the air-filled bowel out of the way. A radiologist may also elect to perform a transvaginal ultrasound for early pregnancies, requiring an empty bladder. Transvaginal transducers are smaller wand-like devices that are inserted into the vagina.

Equipment

A radiologist will use an ultrasound scanner with a video monitor and transducer to perform an ultrasound. The transducer is a hand-held device resembling a microphone used to send high frequency sound waves through the skin into the womb and receive corresponding waves to form an image on the monitor.

Procedure

You will lie on an examination table for an ultrasound. A clear, water-based gel is applied to your stomach to improve contact between your body and the transducer. The transducer is then pressed against your skin and moved around to form a picture of your womb and fetus.

Follow-Up

If any abnormalities are found, your doctor may elect to perform more frequent ultrasounds to check on the status of the fetus and your womb. Scans during the second and third trimesters can detect fetal developmental problems.

References

• RadiologyInfo.org: Obstetric Ultrasound
• University of Maryland Medical Center: Pregnancy Ultrasound