Are Ultrasounds Safe for Babies?

Most pregnant people expect to get at least one ultrasound as part of their prenatal care. But even though ultrasounds are standard, some parents experience reservations about them. They may wonder if they’re actually safe for their growing babies, and whether there are risks to getting multiple ultrasounds during pregnancy. They may also be unsure if all types of ultrasounds are equally safe.

These concerns are understandable—after all, we all want what’s best for our babies. Thankfully, ultrasounds are considered safe, with virtually no associated risks.

Not only that, but ultrasounds have important and beneficial uses in pregnancy. We reached out to experts to help us understand why ultrasounds are used in pregnancy, and what to know about their safety records.

What Is an Ultrasound?

Ultrasounds (sometimes referred to as sonograms) use high frequency sound waves to produce images inside the human body. Ultrasound images can capture what’s happening in real time, so it’s possible to see the movement of blood as well as the movement of a fetus inside the uterus. Ultrasounds do not use the same technology as X-rays; there is no radiation involved.

When an ultrasound is performed, gel is applied to the body and a transducer is used (either inside or outside the body) to transmit sound waves into the body. These sound waves bounce back onto the transducer (like an echo), and images of the organs, tissues, bones, and blood vessels inside the body are generated.

There are two main types of ultrasounds that are used in pregnancy: transvaginal ultrasounds, where the transducer is inserted into the vaginal canal, and abdominal ultrasounds, where the transducer is placed on the abdomen. Typically, transvaginal ultrasounds are used earlier in pregnancy, and abdominal ultrasounds are used in mid-to-late pregnancy.

Why Are Ultrasounds Done During Pregnancy?

There are several reasons why an ultrasound may be performed, and the reason a particular ultrasound is performed may depend on where you are in your pregnancy, says Yvonne Bohn, MD, OB/GYN at Providence Saint John’s Health Center in Santa Monica, CA.

For example, says Dr. Bohn, a transvaginal ultrasound may be performed in early pregnancy to make sure your fetus is developing in the correct location and that your fetus is viable.

“A life-threatening condition called ectopic pregnancy, which is a pregnancy outside the uterus, can be diagnosed on early ultrasound,” Dr. Bohn explains. “Diagnosing this early can prevent fallopian tube rupture and potential death in a mother before the symptoms develop.”

Ultrasounds are often performed mid-pregnancy, at about 20 weeks, to check on the further development of your fetus. This is often referred to as an “anatomy scan” because it checks on your baby's basic anatomy, as well as the location of your placenta. “Serious birth defects can be identified at this time and plans for appropriate safe delivery and post-delivery treatment can be established,” Dr. Bohn explains.

Additionally, if it’s found that the placenta is located in a problematic place (covering the cervix, for example), alternative delivery options will be discussed, such as delivery via c-section.

Benefits of Ultrasounds

Ultrasounds provide important information about your baby’s growth and development, explains Brett Mollard, MD, a diagnostic radiologist who frequently reads obstetric ultrasounds.

“Ultrasounds are able to give excellent detailed pictures of the uterus and baby, allowing us to evaluate many things, from baby well-being and anatomy to placental health,” Dr. Mollard says. “[These tests] are routinely performed to assist with dating (how old is the fetus), to assess fetal anatomy for any possible congenital defects or syndromes, and to follow-up fetal growth and placental health in higher risk pregnancies.”

According to the American College of Obstetricians and Gynecologists (ACOG), other helpful uses for ultrasound during pregnancy may include measuring the volume of amniotic fluid and determining how many fetuses are present.

Are Ultrasounds Safe for Babies?

Ultrasounds have been around for decades, and no concerning safety issues have come up during that time. “Ultrasounds are done because the imaging is safe with over 30 years of data: they do not cause harm to babies,” Dr. Bohn assures.

Dr. Mollard shares a similar sentiment: “Ultrasounds are incredibly safe and, in general, expectant parents should feel completely comfortable about the safety of their baby whenever an ultrasound is performed,” he says.

ACOG summarizes the safety of ultrasounds for babies, saying that there is no data pointing to any safety issues for developing fetuses. Of note, ACOG states that there have been no known connections between fetal ultrasounds and cancer in childhood, birth defects, or developmental issues. However, ACOG does note that these connections could theoretically be found in the future, which is why they recommend that ultrasounds be used only when medically necessary and always by trained healthcare providers.

Are There Any Risks Associated With Ultrasounds?

Again, ACOG states that there are no known risks associated with ultrasounds, but recommends that ultrasounds only be used when clinically necessary.

The U.S. Food and Drug Administration (FDA) agrees that there are many benefits of ultrasounds during pregnancy and that they should be used when medically indicated. However, they also warn of the overuse of ultrasounds, and state that any potential risks to the procedure increase with any “unnecessary prolonged exposure” or anytime ultrasounds are performed by unqualified technicians.

Kelli Burroughs, MD, department chairman of obstetrics and gynecology at Memorial Hermann Sugar Land Hospital agrees that ultrasounds are a low risk procedure, but that they should only be used when needed. Not only that, but there are certain ultrasound procedures that she suggests people shy away from.

“There is no reliable evidence that ultrasounds cause any fetal harm, but non-medical use of ultrasounds should be avoided,” she says. This includes any type of “keepsake ultrasound,” like a 3D or 4D ultrasound that allows you to see aspects of your baby, such as their facial features, Dr. Burroughs says. “There are risks associated with non-medical ultrasounds because patients might be given misinformation, by providing false reassurance, or misdiagnosis,” Dr. Burroughs explains.

The FDA similarly advises against the use of “keepsake” images or videos, because of unnecessary ultrasound exposure.

What to Know About Ultrasound Results

Most of the time, ultrasounds during pregnancy do not return any worrying results. But sometimes they do, and this can be very unnerving for an expectant parent. For example, an ultrasound may detect a birth defect, an issue with your placenta, or issues with your baby’s growth.

Dr. Mollard says that it’s important for parents to keep these results in perspective, and understand that unexpected results aren’t always serious. “We occasionally make incidental findings that largely end up being of no real significance,” he says. “However, when it comes to developing babies, we take these low risks seriously to ensure that everything can safely be ignored and to identify anything truly significant that requires further attention.”

Even if your results end up being concerning, you should know that your medical team will have your best interests at heart and do everything in their power to keep you and your baby safe.

“The most important thing to know about ultrasound results is that you will be contacted if there is anything overly concerning and you will be told...what the next steps are,” Dr. Mollard describes.

In the unlikely event that this happens, parents will be referred to a physician who is highly qualified to handle the medical issue, such as a maternal fetal medicine provider who specializes in high risk pregnancies, says Dr. Mollard. 

A Word From Verywell

Ultrasounds are considered safe during pregnancy and they provide important medical information about your baby. Still, it’s natural to have lingering questions and concerns. If you are unsure about any aspects of ultrasounds, or have specific questions about their use during your pregnancy, please reach out to your OB/GYN, midwife, or healthcare provider.