Although not every expectant woman will undergo an ultrasound exam during their pregnancy, most mums-to-be will have two major ultrasounds: one during the first trimester, to confirm the pregnancy and estimate the foetus’ age, and another one during the second trimester to check if the baby is developing well. This is also when you can find out the gender of your little one!
What is an ultrasound?
A prenatal ultrasound is a test used to look inside a pregnant woman’s abdomen. The technique uses high-frequency sound waves that serve to determine whether your pregnancy and the foetus are doing fine, for instance by checking the foetal heartbeat. The process generates black and white pictures or video so that you can know what’s happening down there and see your little baby.
What to expect during an ultrasound?
Generally, the prenatal ultrasound is performed with the help of a device called a transducer placed on the top of your belly. A cold gel is applied onto your tummy to help improve image quality.
A transvaginal ultrasound, that involves inserting a transducer into your vagina, might be used to take a closer look at your uterus, cervix or ovaries and to detect any issues such as an ectopic or a molar pregnancy. This procedure usually takes place in the early stages of pregnancy.
The average number of ultrasounds required varies from pregnancy to pregnancy and depends also on your ob-gyn. Some women might not need them at all, while others will undergo several of these scans all throughout their pregnancy. They can be performed at any moment during your pregnancy, according to your doctor’s recommendations.
First trimester ultrasound
Congratulations, you’re pregnant! The first ultrasound commonly occurs around 6 to 8 weeks of pregnancy. Your doctor will probably ask you to drink a few glasses of water so that you have a full bladder during the exam, since liquid helps sound waves to travel better. As your baby is very little, your doctor might use a transvaginal ultrasound (which entails inserting a transducer probe into the vaginal canal) to have a closer look. Don’t expect to see much in these first images, the foetus is still tiny.
This first trimester ultrasound serves to confirm your pregnancy, as well as to hear your baby’s heartbeat. This is also the moment to find out the gestational age of the foetus and, therefore, your doctor will be able to determine your due date. At this point, you can know if you’re having a multiple pregnancy. Your ob-gyn will also ensure that you’re experiencing a normal pregnancy and not an ectopic or tubal pregnancy (when the embryo implants outside the uterus).
You might have a second ultrasound (this time performed on your belly and with gel) around 11 to 13 weeks in order to look for signs of Down’s syndrome or trisomy 18. The exam is accompanied by a blood test that will analyse your hormone and protein levels.
Second trimester ultrasound
A detailed ultrasound exam, called an anatomy scan, takes place halfway through your pregnancy, around 18 to 22 weeks. This is the most exciting moment because you are able to have a long look at your baby, who is now more developed! The exam usually lasts for about 20 to 45 minutes, or longer if you have twins or more.
During the second trimester ultrasound, your doctor will evaluate your baby’s health and look for congenital malformations or any abnormalities. In other words, they will look to see if your little one is developing properly and if everything is the way it should be. It’s also the moment to learn the sex of your baby (if you want to, of course), unless your technician can’t obtain a clear image of the genitals.
Third trimester ultrasound
Most women don’t need another ultrasound, but this can sometimes happen if you’re over 35 or you’re past your due date. Your doctor might want to have another look at your baby to check if everything is all right, for instance to see if the amniotic fluid levels are fine or the placenta is where it should be.
If you feel concerned about the safety of prenatal ultrasounds, don’t worry. These scans are considered safe for you and your baby. They don’t involve any radiation or anything that could harm both of you when performed by professionals.