Ultrasound is a technique that uses sound waves to show a picture of your baby in your uterus before birth.
Most healthy pregnancies will not require ultrasounds, but many physicians offer them and many women like to get them to see their baby in the womb, pinpoint a due date, find out the baby’s gender, and check the baby’s health. An ultrasound may be recommended if you have a chronic health condition such as diabetes or high blood pressure.
2D ultrasound, the most common kind, produces images that show your baby’s organs and development, her heartbeat, and movement of her body. If birth defects are suspected, your provider may request a more detailed ultrasound. 3D ultrasound provides a photolike image and allows you to see the height, width, and depth of the fetus. 4D ultrasound allows you to see the fetus in motion. The American Institute of Ultrasound in Medicine considers 3D and 4D ultrasounds a “developing technology,” so health insurance policies will not pay for them.
A second-trimester ultrasound, at 18 to 20 weeks, is considered the best time to check for the risk of birth defects, to date the pregnancy, and determine the baby’s sex.
In a doctor’s office, at an imaging facility, or at a medical center.
Ultrasound can determine the age of your baby, identify a multiple pregnancy (twins or more), check your baby’s growth and size, and show major birth defects. Information obtained by ultrasound can be used to alter prenatal care to improve the chances of delivering a healthy baby.
Ultrasound works by bouncing sound waves off the developing fetus. While you lie on your back, a technician or your healthcare provider applies gel to your abdomen, which allows the sound waves to project more easily on a screen. She rubs a handheld device, called a transducer, across your belly, or inserts a probe into your vagina. You may feel pressure as the provider moves the transducer, but usually no pain.