Ultrasounds have become a regular — and very welcome — part of prenatal care. Early in pregnancy, ultrasounds are used to confirm the fetal heartbeat and a uterine (as opposed to ectopic or tubular) pregnancy. Later, ultrasounds screen for fetal growth, placenta location and umbilical cord, as well as the baby’s general health and anatomy. Ultrasounds can also be useful for checking the length of your cervix, if there is any suspicion that you may be in preterm labor.
When an ultrasound during pregnancy is done?
Usually, a woman gets a minimum of two sonograms during her pregnancy, one in the first trimester and one in the second trimester.
First trimester ultrasound
In the first trimester of pregnancy, an early ultrasound is a routine part of prenatal care at 6 to 9 weeks, allowing parents a welcome first glance of their tiny baby bean. It’s used to:
- Confirm your estimated due date more accurately by measuring the fetus (after the first trimester, ultrasound measurements of the fetus are less accurate)
- Confirm the fetal heartbeat
- Make sure the pregnancy is taking place where it’s supposed to, in the uterus (and to rule out a tubular or ectopic pregnancy)
- Determine the number of foetuses
Second trimester ultrasound
Midway through your pregnancy, usually between week 18 and week 22 second trimester ultrasound is performed not only fun for you to watch, it gives you and your practitioner a clear picture of the overall health of your baby and your pregnancy. It’s a way to:
- See how baby’s developing and offer reassurance that everything is going exactly the way it should be, by measuring the size of your baby and checking all the major organs, measuring the level of amniotic fluid to make sure there’s the right amount, and looking at the location of your placenta
- Tell you your baby’s sex, if you want to know
- Give you a sneak peek at your baby (especially now that she looks like a baby!) — ask the sonographer to point out your baby’s hands, feet, face and tiny organs like the stomach and kidneys
Additional ultrasounds during pregnancy
If you have any spotting during pregnancy, your practitioner will usually perform an ultrasound to confirm that all is well. If you are carrying multiples, you will have frequent ultrasounds to monitor their growth. You may receive an ultrasound to check for changes in the cervix (thinning, opening or shortening) if your doctor thinks you may be at risk of preterm labor.
ACOG (American Congress of Obstetricians and Gynecologists) states that there are no adverse effects of ultrasound on the fetus that have been documented. However, the still do not promote ultrasounds during pregnancy for reasons that do not fall under the medical purview. It is believed that there might not be any confirmed effects of ultrasound on the fetus, but there can be an impact that surfaces in the future.