If you’re worried about ultrasound safety, good for you! You should be. The use of ultrasound in pregnancy has become almost a given. Most women in the US and Canada experience at least one ultrasound during pregnancy. Some experience several. There are certainly appropriate situations for the use of ultrasound, but a healthy pregnancy isn’t one of them.
If, after weighing the pros and cons of an ultrasound, you decide to have one, that’s entirely within your right. What’s important here is to make an informed decision rather than just exposing you and your baby to high-frequency sound waves as a matter of practice.
Is Ultrasound Necessary?
The answer to this question really differs from person-to-person and even situation-to-situation. When a health care provider recommends ultrasound to a pregnant woman, the FDA recommends that mom speaks with them to understand why the ultrasound is needed, what information will be obtained, how the information will be used, and any potential risks.
Medicine is big business. There is significant financial incentive for obstetricians to recommend ultrasounds to their patients, as they can bill many hundreds of dollars to insurance companies for each use. According to the Center for Disease Control (CDC), over-use of technology is one of the major reasons for the rise in healthcare costs.
More and more modern obstetricians have been trained to use ultrasound in place of hands-on skills to evaluate the health of the pregnancy. They use it to evaluate fetal growth and position in the third trimester, which can often be assessed by hands-on examination. They also use it to date pregnancies, which can typically be done with a little detective work.
Ultrasound is often used to determine whether a baby will be too large to be birthed naturally via the birth canal. However, ultrasound has been shown to be an inaccurate measure of birth weight. Further, our pelvic bones are joined together with ligaments that allow the pelvis to widen enough for birth to safely take place - especially when supported in upright and asymmetrical mobile positioning. This is true in almost every case, even when the mother is especially small or the baby especially large.
There are some situations in which an ultrasound is warranted. For example, bleeding in pregnancy or a serious abnormality that requires immediate or high risk hospital care. Or if mom has very irregular or absent cycles during breastfeeding, providing no real guideline for gestational age. Sometimes, if mom has a lot of anxiety about the health of her pregnancy and baby, a normal ultrasound mid pregnancy can provide some reassurance - while still not a guarantee.
The American Institute of Ultrasound in Medicine advocates for use of ultrasound solely for medical purposes, and never for things like keepsake images. And the American College of Nurse-Midwives’ position is that “Ultrasound should only be used when medically indicated.”
What Do We Know About Ultrasound Safety?
Ultrasound waves have the potential to produce biological effects on the body. They can heat bodily tissue, as well as produce small pockets of gas in bodily fluids or tissues (known as cavitation). The long-term consequences of these effects are still unknown.
Dr Sarah Buckley provides an extensive article in which she weighs ultrasound safety. In it she says,
“If there is bleeding in early pregnancy, for example, ultrasound may predict whether miscarriage is inevitable. Later in pregnancy, ultrasound can be used when a baby is not growing, or when a breech baby or twins are suspected. In these cases, the information gained from ultrasound may be very useful in decision-making for the woman and her carers. However the use of routine prenatal ultrasound (RPU) is more controversial, as this involves scanning all pregnant women in the hope of improving the outcome for some mothers and babies.”
Dr Buckley goes on to say,
“Studies on humans exposed to ultrasound have shown that possible adverse effects include premature ovulation, preterm labour or miscarriage, low birth weight, poorer condition at birth, perinatal death, dyslexia, delayed speech development, and less right-handedness.”
Despite its rampant use, there has not been sufficient testing for ultrasound safety - especially concerning routine use in healthy pregnancy. In fact, there has been very little testing at all since the 1980s even though the FDA allowed exposure limits to increase by 8 fold in 1992.
It’s important to acknowledge here that technology is often assumed safe until proven otherwise. Just a couple generations back, it was general practice to x-ray pregnant mothers. Sounds crazy now that we know more about the dangers of x-rays to the developing fetus, but back then it made perfect sense.
As Dr Kelly Brogan states, “Multiple Cochrane reviews have demonstrated a lack of perinatal mortality benefit for routine ultrasound in a normal pregnancy, and an increased risk of cesarean section with third trimester screening. A review of outcomes literature condemns ultrasound when used for dating, second trimester organ scan, biophysical profile, amniotic fluid assessment, and Doppler velocity in high and low risk pregnancies.”
While our reasons for using ultrasound are typically focused on healthy pregnancies and healthy babies, there has been virtually no proof that more ultrasounds in a population equate with better health. In fact, false positives of congenital malformations are not unusual. Sadly, this has lead to more invasive testing and abortions misunderstood to be medically necessary when there is nothing actually wrong. At the very least, this puts undue stress on momma, partner and baby.
In my opinion, technology has put distance between mommas and care providers. In situations where a midwife historically would take a literal hands-on approach to mom and baby’s health, technology now allows for a disconnect where mom is sometimes never touched by her birthing support team. My belief is that this impersonal approach can do just as much harm as the technology can.
The over-use of ultrasound also undermines a woman’s trust in her healthy body’s ability to grow and birth her healthy baby, as modern day families are putting more and more trust in technology over themselves.
Alternatives to Ultrasound
We do not fully understand the effect of directing loud sound waves at baby so frequently, but it does alter DNA in the test tube and there is strong evidence to show that any damage done is cumulative. So, if you must have an ultrasound, keep it as brief as possible and limited to as few as possible. If all is well and you know your cycles or date of conception, but you really want one, do it mid pregnancy…and of course, make sure to request a keepsake picture of your baby.
A doppler is an ultrasound device that can detect fetal heartbeat as early as 10-12 weeks, depending on the device, the location of baby, and position of mom’s uterus. It is used for each prenatal visit in many obstetrical care offices and clinics. If you want to minimize ultrasound exposure, ask for the fetoscope.
A fetoscope, which is similar to a stethoscope and works to amplify baby’s heartbeat, can be used in place of ultrasound or doppler after around 20 weeks gestational age to listen to the fetal heartbeat. It can also help assess baby’s position in later pregnancy.
When baby starts to move regularly, especially in the third trimester, I teach fetal movement awareness and kick counts. Basically, babies sleep a lot, especially when you are busy running around; but they tend to get up and become active after you eat and when your’e resting. Become aware of when and how often your baby is most active and take notice of your baby’s typical daily patterns of movement. An active baby, moving as much as usual, is a sign of fetal health and well-being. If you did not feel your baby move as much usual on a given day, eat food that has previously stimulated lots of fetal activity - usually carbohydrates like a peanut butter and jelly whole grain sandwich or cereal and nut milk - plus have two glasses of orange juice and a cup of coffee; recline in 30 - 40 minutes and count at least 10 separate kicks, body shifts, punches in the hour. Most babies will produce more than that in a few minutes, but if you are not feeling 10 separate moves in that hour, call your provider.
For most of history we did not know we were having a boy or a girl until the birth of our baby. There is something special about the surprise. But for those wanting to know the sex of their baby, blood tests are now available and are actually more accurate than ultrasound for this purpose.
Medical interventions like ultrasound often play into our fears and turn us away from our intuition. We have come to have less trust in the process and believe that we need to rely on technology to assure us that our babies are safe. As mommas, we have thousands of years of the birthing wisdom of our elders that we carry in our DNA. Is that less reliable than a relatively new, under-tested technology when all is well?
Midwives typically use touch and hand skills in place of technology like ultrasound. As a wholistic and integrative midwife that specializes in healthy pregnancy, I always give the option for ultrasound, and discuss the pros and cons with each family in my care. Some opt out of all unless there is an issue or complication when the benefits outweigh the potential risks of sonogram. Some do want one to confirm they have a baby in the uterus with a heart beat before it is too early to tell in the office, and a basic scan between 18 -22 weeks. For those birthing at home, some want just this mid-pregnancy ultrasound to check baby’s anatomy and that the placenta is in the right place, so they are reassured there is nothing detected that warrants birth in higher risk hospital setting.
As midwives, we do not fix what is not broken. We instill trust in the pregnancy and birth process, and have confidence in a mom’s ability to do it.