How do you prepare for an ultrasound?

Karin Field, who had an ultrasound scan at 18 weeks gestation, says she had no special instructions to prepare for the test. “I didn’t have to drink water, or change into a hospital gown or anything, just pull my shirt up and my pants down as I lay on the table. The technician put a towel over the waistband of my pants to protect it from the gel,” she says.

In some locations, and depending on the stage of pregnancy, you may be asked to drink several glasses of water before the scan is done so that your full bladder pushes up your uterus and makes it easier to get a good picture of the baby. Your doctor or midwife will give you the instructions when he or she gives you the referral form.

Darcie Light of Richmond, BC had a trans-vaginal first-trimester ultrasound, and says: “Preparing for this involved emptying my bladder, undressing from the waist down, covering myself with a sheet, and getting positioned on the exam table with my feet in the stirrups.” The technician used a lubricated probe inserted into the vagina. “The technician asked me to insert the probe myself, then moved it around to get the images needed,” she says. This trans-vaginal type of ultrasound may also be used in late pregnancy.

What happens during the procedure?

For Field’s second-trimester ultrasound, the technician first took a few minutes to explain the process and tell her how long it might take. “She put warm gel on my belly and then rubbed the transducer – it looks a bit like a microphone – over my belly. At the end, she called in my husband, and showed us the baby’s head, heart and back, and told us that she couldn’t really see the baby’s gender because of the position,” explains Field.