Over the span of 30 years there has been a steady increase in the routine use of ultrasound technology during pregnancy. Initially, women received one, maybe two ultrasounds to determine the sex of the fetus, to determine size and confirm the EDD, and to assess for any congenital abnormalities. Now, women often received multiple throughout their pregnancies, but we'll get to that in a bit.
Ultrasounds are generally thought to be completely safe and to carry very little risk, but unfortunately this isn't true. Contrary to over 30 years of warnings about the potential risks of ultrasound exposure and other non-evidence based interventions, the market for medical technology in pregnancy and childbirth has continued to expand. In many cases there is actually evidence against the use of ultrasounds for the very complications they were first used to prevent or ameliorate.
The wide-spread and routine use of ultrasound imaging throughout pregnancy has never been ADEQUATELY tested for safety or efficacy... like so many of the procedures used on women and babies in medicine, these hadn't been proven safe before tested en masse. I, for one, do not want to be one of the medical community's test subjects!
First, what is an ultrasound?An ultrasound, also called a sonogram, is a medical imagining technique that uses high frequency sound waves to view internal parts of the body. In pregnancy, ultrasound is used to view inside the mother to see the developing baby or the placenta.
In an ultrasound, a transducer (which emits the high-frequency sound waves) is placed on the mother's abdomen and a gel is used to help the transducer glide over the mother's skin, creating a more fluid image. These sound waves are sent out and when they encounter an object (such as a baby), they "bounce back" or are reflected back to the transducer and create an image on the screen.
How many ultrasounds are women having?
More and more women are receiving multiple ultrasounds throughout their pregnancies and based on the lack of research demonstrating even ONE ultrasound is safe (let alone multiple ultrasounds), this is cause for concern! The recently released Listening to Mothers Survey III(1) demonstrated that 90% of women are receiving two or more ultrasounds! and almost 1 in 2 women are having 4 or more!!! You can read more about those results at my post here, but the gist of the issue is, most women are receiving FAR TOO MANY ultrasounds!!!
What's worse is that these technologies keep expanding and mother's are led to believe all these scans carry little to no risk to her baby and actually increase her bond with the child. Would women refuse ultrasounds if they knew the actual risks?
Is it really that big of a deal?Yes! With such little research about the effects of ultrasound imagining on the developing fetus and with 1 in 2 women receiving 4 or more ultrasounds during pregnancy, I'd say there's a BIG problem!
The high frequency sound waves emitted by ultrasounds cause vibrations in body tissues and this increases the temperature of the exposed tissues (FDA)(2); even small increases in temperature can cause cellular and tissue damage, especially in a developing baby. Also, these high frequency sound waves are amplified within the liquid environment of the placenta and some argue that this can sound like a freight train approaching the station; if directed at a fetus's developing ears it could potentially cause damage, let alone terrify and stress the baby. In addition, I haven't even mentioned the inaccuracy (false positives and negatives) of ultrasounds and the stress these can cause for the mother, father, and baby! This will have to be in another post as this one is already VERY lengthy :)
Is there research?1. Recent animal model research from Yale was the first of its kind to evaluate ultrasound waves on neuronal development, using a mouse model. The research demonstrated that with ultrasound frequencies similar to those experienced by human babies in utero there were small but highly significant disruptions in the movement and growth of neurons. They state, "...the findings show that ultrasound waves can disrupt physical interactions between migrating neurons and their fiber guides. Human neurons migrate for much longer distances in the fetal brain compared to the mouse model used here. This means that the neurons take much longer (days to weeks) to get to their final destination, perhaps leaving them more vulnerable to possible disturbances by extreme, multiple exposures to ultrasound waves,"(National Scientific Council on the Developing Child, 2007)(3).
2. In a 10 year randomized control trial, published in The Lancet in 2004 (4), researchers began with two large groups of women, randomized to receive either 5 ultrasounds or 1 ultrasound. The children were followed to 8 years of age and assessed periodically throughout their development on a number of physical and mental scales. Overall the research did not find statistically significant differences in physical growth or tests of mental ability by 8 years of age, but there were a few concerning findings and the authors conclude: "Reassurances provided by our results do not lessen our need to undertake further studies of potential bio-effects of prenatal ultrasound scans. ... In views of the widespread and liberal use of this technology we are responsible for ensuring the safety of its use. Uncertainty remains about several potential issues, one of which is handedness...such a possibility could result from effects on neuronal migration, which is active at the time of many prenatal scans."
Another finding from this study was that babies born to the '5 ultrasound' group were significantly shorter in length at birth (although average weight was similar); by age 1 these height differences were gone. The authors discuss the possibility that if ultrasound scans are affecting fetal growth, then it is due to an effect on the developing fetal bone, rather than the supply of nutrients from the placenta.
My thoughts: Other studies have also addressed this issue leading me to believe that this deserves serious attention! The skull is so close to the brain, think about what this may mean for the sensitive neuronal development of the brain when the skull is heated during an ultrasound.
3. The Cochrane review is a well trusted source that evaluates the current research on relevant topics and provides a consensus for the findings of that research. Regarding ultrasound scans AFTER 24 weeks of gestation, the Cochrane review(5) has this to say: "Based on existing evidence, routine late pregnancy ultrasound in low-risk or unselected populations does not confer benefit on mother or baby. It may be associated with a small increase in caesarean section rates. There is a lack of data about the potential psychological effects of routine ultrasound in late pregnancy, and limited data about its effects on both short- and long-term neonatal and childhood outcome."
And what about the research for ultrasounds before 24 weeks gestation?(6) ... well, the research has demonstrated that the only uses for early ultrasounds are to help to reduce the rate of "missed" multiple gestation's (twins), as well as giving a more accurate gestational age dating, so women aren't induced too early for a "post-date" baby...
Ok, does anyone see that this statement is FULL of medical intervention! If doctors weren't so "induction happy" and inept at diagnosing multiple gestations with their hands and ears (a fetoscope), then we wouldn't need the potentially risky ultrasounds! The Cochrane Review also state that the research doesn't appear to show that there are long term cognitive problems caused by early ultrasounds... ummm, but they stated the research isn't clear on the safety of ultrasounds for the developing fetus (think brain and neuronal growth) in their previous statement!
American College of Obstetrics and Gynecology (ACOG)(7) endorses a statement from the American Institute of Ultrasound Medicine (AIUM) in which they warn against ultrasounds for non-medical purposes, such as for keepsakes. They caution on the over-use of ultrasounds because the research hasn't demonstrated that they are safe to use routinely (or even at all) in pregnancy. Here is what AIUM has to say: "The AIUM advocates the responsible use of diagnostic ultrasound. The AIUM strongly discourages the non-medical use of ultrasound for psychosocial or entertainment purposes. The use of either two-dimensional (2D) or three-dimensional (3D) ultrasound to only view the fetus, obtain a picture of the fetus or determine the fetal gender without a medical indication is inappropriate and contrary to responsible medical practice. Although there are no confirmed biological effects on patients caused by exposures from present diagnostic ultrasound instruments, the possibility exists that such biological effects may be identified in the future. Thus ultrasound should be used in a prudent manner to provide medical benefit to the patient."
Here is what the FDA(2) has to say about ultrasound use:
"Even though there are no known risks of ultrasound imaging, it can produce effects on the body. When ultrasound enters the body, it heats the tissues slightly. In some cases, it can also produce small pockets of gas in body fluids or tissues (cavitation). The long-term effects of tissue heating and cavitation are not known."
"Because of the particular concern for fetal exposures, national and international organizations have advocated prudent use of ultrasound imaging. Furthermore, the use of diagnostic ultrasound for non-medical purposes such as fetal keepsake videos has been discouraged."
My thoughts: Due to the uncertain safety of ultrasounds to fetal development, not only should parents avoid non-medical ultrasound imaging for the purpose of memorable photos, but parents should question the use of routine ultrasound from medical providers during pregnancy and limit the frequency and length of fetal exposure. There are also no accepted standards (national or international) for the sound wave frequency that is deemed appropriate to use during fetal diagnostic imaging, therefore, many medical practices use frequencies that are hundreds of times higher than may be necessary, not to mention 'safe'.
This isn't OK!!!!
Other people's thoughts and articles...
Here are a few other resources about ultrasounds if you are interested in reading more into what other people have to say.
An article found in MidwiferyToday(8), by Beverly Beech, named the commonly cited reasons for performing ultrasound scans which been shown to be ineffective and sometimes even dangerous to the safety of the baby. The article includes research about:
- Miscarriage- ultrasound leads to an increase risk of miscarriage (also among ultrasound technicians using the equipment all day)
- Placenta Previa - ultrasound is not accurate at diagnosing placenta previa; increased c-section rate among women diagnosed and misdiagnosed
- Congenital Birth Defects - Low accuracy in correctly identifying a congenital defect in utero; some of these women received up to 7 ultrasounds for a diagnosis; Increased antenatal death rate among the group diagnosed by ultrasound (vs. no ultrasound and diagnosis upon birth) - this means babies having ultrasounds meant to HELP them, DIED more!
- Intrauterine Growth Retardation (IUGR)- "Small" babies determined to have IUGR by ultrasound imaging had higher rates of c-section delivery and higher rates of pre-term birth, meaning that these babies had unnecessary c-sections due to their "diagnosis". Furthermore, there is currently no recognized treatment for IUGR so I ask, why we are screening for it?
Ms. Beech also states: "Women are now exposed to so many different types of ultrasound: Doppler scans, real-time imaging, triple scans, external fetal heart-rate monitors, hand held fetal monitors. Unlike drugs, whereby every new drug must be tested, the rapid development of each new variation of ultrasound machine has not been accompanied by similar careful evaluation by controlled, large-scale trials."
NaturalNews(9) discusses the issue of ultrasound technology being used on men's testes as a form of birth control sterilization lasting for about 6 months - how is this same "energy" ok for developing babies? Also, Beverly A Lawrence Beech makes the point that when a pregnant mother receives ultrasounds (let's say 4), her female baby's eggs are also scanned, years later when the daughter is pregnant with a baby of her own, this baby will have already had 4 scans.
Back in 1999, Dr. Marsden Wagner (Neonatologist) wrote, "Although we now have sufficient scientific data to be able to say that routine prenatal ultrasound scanning has no effectiveness and may very well carry risks, it would be naive to think that routine use will not continue." MidwiferyToday.(10)
It is time to practice evidence-based medicine. Do away with routine and unnecessary ultrasounds!
Coming soon... Ultrasounds and the rising rates of Autism, is there a strong correlation? As well as thoughts about the inaccuracy of ultrasounds, the false negative/false positive results, and the impact this can have on a mother's stress in pregnancy! I'm also reading the Business of Baby and will comment on the Ultrasound chapter soon!
~Wisdom and Birth
1. Declercq ER, Sakala C, Corry MP, Applebaum S, Herrlich A. (May 2013). Listening to Mothers III: Pregnancy and Birth. New York: Childbirth Connection.
2. U.S. Food and Drug Administration. (Updated 06/06/2012). Ultrasound imaging. Retrieved May 2013 from http://www.fda.gov/Radiation-EmittingProducts/RadiationEmittingProductsandProcedures/MedicalImaging/ucm115357.htm
3. National Scientific Council on the Developing Child. (2007). ScienceBriefs: The Impact of Ultrasound on Developing Brain Neurons. Retrieved May 2013 from http://www.developingchild.net.
4. Newnham JP, Doherty DA, Kendall GE, Zubrick SR, Landau LL, Stanley FJ. (2004). Effects of repeated prenatal ultrasound examinations on childhood outcome up to 8 years of age: follow-up of a randomized controlled trial. The Lancet 2004; 364: 2038-44.
5. Bricker L, Neilson JP, Dowswell T. (2008). Routine ultrasound in late pregnancy (after 24 weeks' gestation). Cochrane Database of Systematic Reviews 2008, Issue 4. Art. No.: CD001451. DOI: 10.1002/14651858.CD001451.pub3.
6. Whitworth M, Bricker L, Neilson JP, Dowswell T. (2010). Ultrasound for fetal assessment in early pregnancy. Cochrane Database of Systematic Reviews 2010, Issue 4. Art. No.: CD007058. DOI: 10.1002/14651858.CD007058.pub2.
7. American College of Obstetricians and Gynecologists. (2004). Committee Opinion #297: Non-medical use of obstetric ultrasonography. Retrieved May 2013 from http://www.acog.org/Resources%20And%20Publications/Committee%20Opinions/Committee%20on%20Ethics/Nonmedical%20use%20of%20Obstetric%20Ultrasonography.aspx
8. Beech, BL. (1999). Ultrasound: weighing the propaganda against the facts. Originally printed in Midwifery Today, issue 51. Retrieved May 2013 from http://www.midwiferytoday.com/articles/ultrasound.asp
9. Adams M. (2010). If ultrasound destroys sperm, why is it safe for a fetus? Retrieved May 2013 from http://www.naturalnews.com/028853_ultrasound_fetus.html
10. Wagner M. (1999). Ultrasound: more harm than good? Originally printed in Midwifery Today, issue 50. Retrieved May 2013 from http://www.midwiferytoday.com/articles/ultrasoundwagner.asp