Ultrasounds are a common practice today for a variety of health diagnostics, and they can be quite useful in certain contexts. Most often we see them used on pregnant mothers for early diagnosis of fetal anomalies. Despite their widespread use, recent evidence suggests that ultrasounds carry significant risks, especially during early pregnancy.

When I learned about this last year, it totally blew my mind. A study done on mice showed that those exposed to ultrasound in utero showed clinically significant alterations in memory, social behaviors, learning and neuroanatomy. Now that I’ve pulled together information from this study and several others, health data from around the world and some alternatives to ultrasound, I want to share with you all, so that you can make the best, most informed decision possible about yours and your familys’ health.

USA vs The World

Let’s start by comparing the use of ultrasound here in the USA, with Europe and other developed nations. Here in the US, we tend to use ultrasound far more frequent than Europe, and there are fewer guidelines in place, directing how early in the pregnancy this technology should be used and in what situations.

For example, in Europe scans before 10 weeks are not recommended unless “medically indicated” due to possible ectopic pregnancy or other emergency health concern. In contrast, it is pretty routine to have a first ultrasound in the 6-8 week range here in the US to check for ectopic pregnancy or even just for reassurance.

How Ultrasound Works

Ultrasound works by using high-frequency sound waves to create images of the inside of the body. A handheld device called a transducer sends these sound waves into the body, and when they bounce back (like an echo), they are captured to form an image on a screen. Since different tissues and fluids reflect sound differently, ultrasound can provide real-time images of organs, tissues, or a developing baby in pregnancy.

Heat from Ultrasound

When high-frequency sound waves, such as those used in ultrasound, pass through tissues, they cause the molecules in the tissue to vibrate. This vibration generates friction, which can produce heat. The energy from the sound waves is absorbed by the tissue, and the more energy absorbed, the more heat is generated.

The amount of heat produced depends on factors like the duration of the ultrasound, the intensity of the sound waves, and the type of tissue being imaged.

Ultrasound As Contraceptive in Monkies

A recent study done on rhesus monkeys showed that ultrasound could be a promising reversible form of male contraception. Researchers tested two methods: one where the scrotum was placed in a cup of saline and exposed to ultrasound, and another where the ultrasound was applied directly to the scrotum. Both approaches led to a drop in sperm movement and quality, but the cup method proved more effective, reducing sperm counts by up to 91.7%. The effects lasted for about eight weeks before sperm counts gradually returned to normal.

This study (and several others done on animals with similar results) suggests that ultrasound has a significant impact on sperm at the cellular level, reducing their movement, shape, and overall quality. If ultrasound can affect sperm in this way, it raises concerns about its use on developing fetuses, particularly before 10 weeks of gestation when they are still composed of only a few cells. Early fetal development is a critical time when cells are rapidly dividing and highly sensitive to external factors.

Advocates for ultrasound may claim that these findings are only applicable to monkies or that they are due to the duration of the scans, but the study claims that they samples/testes were only treated for 30 seconds. Most anatomy ultrasound appointments can last anywhere from 30 minutes to an hour — far longer than the 30 seconds mentioned in the study.

These results were also found to extend to all treated animals so far, including dogs, cats and even human men. If ultrasound can impact sperm cells in adult males, imagine what effects it could have on the rapidly developing cells of a fetus.

Why Do We Even Use Ultrasound, Anyway?

Well, turns out that’s a good question. Providers will say that ultrasounds are a tool for early detection of severe fetal abnormalities. That is true, but we have several other non-invasive or blood test ways of rooting out those abnormalities that are much more accurate and safe compared to ultrasounds. Parents, of course, want the keepsake pictures of their little one as they develop in the womb. But really, if we have a safer option than ultrasounds, why not just use that for low-risk pregnancies instead like they do in Europe?

We can speculate that the culture here in the USA is probably to blame. Our healthcare system views obstetrics as a big money-maker and so takes more suggestion from the wishes of its clients than is allowed in other countries. Ultrasound brings in money for the healthcare industry, (between $200 — $1000 per appointment) so there is an incentive to have every mother get one to “rule out” possible abnormalities.

Some Questions to Ask your Provider:

Is this ultrasound medically necessary, or is it optional?
What specific information are you looking to gather from this ultrasound?
Are there any alternative ways to obtain the same information without using an ultrasound?
At what stage of pregnancy is ultrasound most critical, and is it safe to wait until later?
What are the potential risks of having an ultrasound, especially in early pregnancy?
Is there any evidence of long-term effects on children exposed to multiple ultrasounds during pregnancy?
How many ultrasounds do you typically recommend during pregnancy, and why?
Can we reduce the number of ultrasounds in my pregnancy if everything appears normal?
Are the ultrasound machines used here regulated for the safety of the fetus, and are they regularly inspected for safety?
How does your experience and expertise with ultrasounds compare to other non-invasive screening methods?

Comparing Alternatives to Ultrasound

Test Type	What Information Can Be Found	Limitations/Accuracy Issues
Cell-free DNA Testing (cfDNA)	Screens for chromosomal abnormalities (e.g., Down syndrome/Trisomy 21, Trisomy 18, Trisomy 13). Can determine fetal sex.	Does not assess physical development or anatomy. Not diagnostic, only shows risks.
Noninvasive Prenatal Testing (NIPT)	Screens for chromosomal abnormalities (same as cfDNA). May detect certain rare genetic disorders. Can detect fetal sex.	Does not assess anatomy, organ function, or growth. Not diagnostic; follow-up tests needed for confirmation.
Maternal Serum Screening (Quad Screen)	Screens for risks of neural tube defects (e.g., spina bifida), Down syndrome, and other chromosomal conditions.	Risk assessment only; cannot detect or confirm physical anomalies. False positives/negatives possible.
Fetal Echocardiography	Detailed information on fetal heart structure and function. Can diagnose specific congenital heart defects.	Focuses only on the heart. Does not provide any information on other organs or fetal growth.
Fetal MRI	Provides detailed images of specific organs (e.g., brain, spine). May be used if concerns arise about specific abnormalities seen on ultrasound.	Limited use for general anatomical screening. Expensive, not routine. Only used for suspected issues, not general screening.
Ultrasound (Routine Anatomy Scan)	Provides comprehensive views of fetal anatomy (organs, limbs, head, heart, etc.). Assesses fetal growth, placental position, amniotic fluid levels, and fetal movement. Detects some physical anomalies (e.g., neural tube defects, cleft palate).	Anatomical assessments are often inaccurate (e.g., estimating fetal size, limb development, detecting minor defects). Some organs or abnormalities may not be clearly visible depending on fetal position, maternal body factors, or operator skill. Not perfect for detecting subtle or rare conditions.

Ultrasound Accuracy

While ultrasounds are used and trusted by parents and physicians alike, they are not infallible and are not, on the whole, known for their accuracy. It’s so crazy to me that ultrasounds are held in such high regard despite being so incredibly inaccurate.

Anecdotally, I know countless women who got the ultrasound and were told they would need a c-section because their baby was “too big”, only to find out when they were born that the ultrasound was several pounds off from the actual birth weight.

What About 2nd and 3rd Trimester Ultrasounds?

We’ve talked about the potential for issues with ultrasounds done early on in the pregnancy, but what about later on, after the first trimester?

A recent study done on mice showed that ultrasound-exposed pups were less interested in social interaction and exhibited more activity in social situations compared to a control group. Researchers applied 30 minutes of diagnostic ultrasound to pregnant mice at embryonic day 14.5 and later assessed the social behavior of their male offspring. These findings suggest that in utero exposure to diagnostic ultrasound can potentially alter social behavior in mice, raising questions about how such exposure may influence neurodevelopment and its relevance to autism-like behaviors.

Unfortunately and fortunately, there are very few studies done on human children looking into brain development after exposure to ultrasound. It’s also true that mice are not humans, and that we cannot extrapolate data from mice and assume it also applies to humans, (unless it’s the COVID-19 vaccine booster trials, of course). That said, it doesn’t make me feel especially comfortable knowing it has the potential to have this effect.

Conclusion

If you know me, you know I am all about medical freedom and informed consent. It’s truly a crime that so much information that can impact our health is withheld in the name of making money or inconvenience of taking the time to present it to patients. Remember that you are in charge at your doctors appointment, and that you can ask for alternative screening options.

I personally will be avoiding an ultrasound for the entirety of my pregnancy whenever I have kids because, to me, the risks do not outweigh the benefits. There is so much about how our brains and bodies function that remains unknown, I feel that keeping close to the way we evolved over millennia makes the most sense. That said, even though I’m choosing to avoid ultrasound for my children, I fully support and respect an informed parents decision to do whatever they feel is best for their child always.

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