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Hey, baby! Get ready for your first close-up — it's time for an ultrasound.
Ultrasounds have become a regular — and very welcome — part of prenatal care. Early in pregnancy, ultrasounds are used to confirm thefetal 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.
WHO AN ULTRASOUND DURING PREGNANCY IS FOR
All pregnant women should receive more than one ultrasound during pregnancy.
HOW AN ULTRASOUND DURING PREGNANCY IS DONE
Ultrasound examination is often performed using a wand or transducer over the abdomen (transabdominal). A (chilly) gel is rubbed onto your belly and then a wand called a transducer, which emits sound waves, is rubbed over the area. These sound waves bounce off structures (otherwise known as your baby) to produce an image you can view on a video screen. Note: The same technology is used in a handheld Doppler, only it's not as sophisticated (which means no pictures to share).
During the first trimester (or for cervical checks), your practitioner may instead perform a transvaginal, or internal, ultrasound, especially early on. The same principle is at work, but a small, long transducer wand, which is first covered with a condom and sterile lubricant, is inserted directly into the vagina. The practitioner will move the wand within the vaginal cavity to scan your uterus. This allows your practitioner to see the fetus even before it's detectable on a transabdominal ultrasound.
The procedures can last from five to 30 minutes and are painless, except for the discomfort of the full bladder necessary for the first-trimester transabdominal exam. They can be somewhat uncomfortable if the sonographer needs to press hard on your abdomen to see a particular part of your baby more clearly.
WHEN AN ULTRASOUND DURING PREGNANCY IS DONE
Usually, a woman gets a minimum of two sonograms during her pregnancy. In the first trimester of pregnancy it can be done anytime, depending on the reason for performing one. A first trimester ultrasound (usually a basic level 1 ultrasound) is used to:
- Confirm the fetal heartbeat and a uterine (as opposed to ectopic or tubular) pregnancy
- Date a pregnancy
- Determine the number of fetuses
- Locate an IUD that was in place at the time of conception
A gestational sac can be visualized on ultrasound as early as 4 1/2 weeks after your last period; a heartbeat can be detected as early as 5 to 6 weeks (though it might not be detected that early in all cases).
Midway through your pregnancy (usually between week 18 andweek 22), a detailed anatomy scan called a level 2 ultrasound is performed, which is generally done by a trained sonographer in a hospital or specialized clinic, where the equipment is more sophisticated.
Sometimes a mom-to-be will have additional ultrasounds over the course of her pregnancy if she is among the one in four women who is considered high-risk. 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. Additionally, ultrasounds are a part of several other tests including chorionic villus sampling (CVS), amniocentesis, nuchal translucency screening and biophysical profiles.
THE DIFFERENCE BETWEEN SONOGRAM AND ULTRASOUND
Though the words sonogram and ultrasound are often used interchangeably, a sonogram is the actual picture that you'll take home (and show everyone you've ever met and a few people you haven't) from an ultrasound scan. Yes, it's a wonderful keepsake, but the medical purpose of these freeze-frame pictures is for the sonographer to be able to accurately measure your little one (something that would be nearly impossible on a moving target).
RISKS
Ultrasounds are noninvasive and very low-risk. That said, medical guidelines caution against unnecessary exposure. Because no researcher would willingly put a fetus in harm's way in the name of science, it's difficult to study the long-term effects of ultrasound use — which means there is the possiblity of unintended consequences with overuse. What's more, though ultrasounds are usually relatively accurate at estimating a baby's size, they can under- or over-estimate weight, especially if they're overused, which may occasionally result in unnecessary C-sections or premature deliveries. That's why the American Congress of Obstetricians and Gynecologists along with the Food and Drug Administration urge practitioners and patients to only use ultrasounds if they're medically necessary. These groups also recommend that pregnant women avoid keepsake 3-D and 4-D sonograms during pregnancy advertised by private companies (which may even be available in your local mall) along with at-home fetal monitors.
Some research, however, has found that the average number of ultrasounds women are receiving is much higher — more than five over the course of pregnancy, on average. So if your doctor recommends more than two ultrsounds when you're expecting, ask questions to ensure that what you're receiving is medically required and in the best interests of the health of your baby.
