First Trimester

Q&A: What Happens During An Ultrasound?

When will I have my first ultrasound, and what are they looking for?

Maybe your first trimester, maybe the second. Ultrasound uses sound waves and echoes to create a moving image of your fetus and show what’s going on inside your womb. (Quick vocab lesson: Ultrasound is the procedure; sonogram is the image it creates.) Some docs routinely perform first trimester ultrasounds between weeks 4 and 12 to confirm the fetus’ age. Or, your doc might perform one in the first trimester only if there are signs of multiples, miscarriage or ectopic or molar pregnancy.

Between weeks 18 and 22, most women have a more detailed level two ultrasound. Now, your doc is checking for fetal heartbeat, location, breathing, movement and size, placenta location, amount of amniotic fluid, abnormalities and yes, gender. Look forward to the fuzzy picture you’ll get to take home as a souvenir of baby’s first photo session.

Throughout your pregnancy, your doc might order additional ultrasounds to check on any issues or possible complications. Or, you might not have one at all — according to the March of Dimes, only 70% of pregnant women have the procedure. In low-risk pregnancies, the American College of Obstetricians and Gynecologists recommends ultrasound should only be used to answer specific medical questions (not as routine procedure). Don’t let that scare you, though — of the multitude of large studies performed over the last 30 years, none have linked ultrasound to any harmful effects, for you or your fetus.

By Paula Kashtan