authors of a 2010 Cochrane review on fetal ultrasounds have stated this:
“Subjecting a large group of low-risk patients to a screening test with a relatively high false positive rate is likely to cause anxiety and lead to inappropriate intervention and subsequent risk of iatrogenic morbidity and mortality” (Alfirevic, Stampalija and Gyte, 2010).²⁵
In their article ‘Routine ultrasound in late pregnancy (after 24 weeks’ gestation)’, these authors found that “there is no evidence that routine ultrasound in late pregnancy improves perinatal outcome. Its use may increase the rate of caesarean section, and hence the risk of iatrogenic morbidity” (Bricker et al. 2008).²⁶
Like many other pregnancy and birthing interventions, we have been conditioned to think that what we are told to do must be the right thing to do. There is plenty of research to suggest that ultrasounds are not perfect and are certainly not recommended for routine use in low-risk pregnancies.
A Cochrane review on ultrasounds in 2015 also found the following:
"No clear benefit in terms of a substantive outcome measure like perinatal mortality can yet be discerned to result from the routine use of ultrasound" ²⁷ (Alfirevic et al. 2015).
There is evidence which suggests that ultrasounds can cause higher than safe levels of heat. The sonar beam can cause heating in the tissues being scanned. Doppler ultrasound which uses continuous rather than pulsed waves, has been found to cause significant heating, (especially in the baby's developing brain.)²⁸ During normal pregnancy increases in whole-body temperature up to 2.5 degrees C (36.5F) are considered safe. Heating in late-pregnancy fetal tissues exposed to normal pulsed and continuous Doppler ultrasound may be 1.4 - 5.8 degrees C (significantly higher than what is considered to be 'safe' levels.)
Both animal and human studies have shown that elevated temperature can cause abnormal development and even birth defects.
A Cochrane Review of routine ultrasound in late pregnancy concluded the following:
“There is no evidence that routine ultrasound in late pregnancy improves perinatal outcome. Its use may increase the rate of caesarean section, and hence the risk of iatrogenic morbidity. As a result of this review, it is not clear what aspects of late pregnancy ultrasound may be valuable in centres where it is undertaken” (Bricker et al. 2008).²⁹
One of the other issues with studies observing the effects of prenatal ultrasounds is that the scanning intensities today are up to 6-8 times higher than they were in the 1990s, when all of the large population-based studies assessing ultrasound safety were done.
Even the FDA (U.S. Food & Drug Administration) warns against the routine and medical unnecessary use of fetal ultrasounds. In a statement on their website, they warn that the long-term effects of heating and cavitation are unknown and that ultrasound scans should be done ‘only when there is a medical need, based on a prescription’.³⁰
A 2002 review of the safety of ultrasound in the prestigious journal of Epidemiology concluded:
“Until long-term effects can be evaluated across generations, caution should be exercised when using this modality during pregnancy.” ³¹
50 Studies that demonstrate potential dangers
There are now at least 50 Chinese studies that demonstrate the potential dangers of ultrasound use in pregnancy, including irrefutable evidence that human babies are always harmed in some way, whether it be subtle trauma or prenatal scars. (The causal studies were done on babies who were given diagnostic ultrasounds prior to scheduled abortions in China.)
Based on the conclusions of the studies it was determined that prenatal ultrasound can be a contributing factor in the following conditions:
ASD (Autism Spectrum Disorder)
ADHD
Genetic Damage
Jaundice
Childhood cancers (eg. Leukemia)
Skin Diseases
The studies can be found in the book Diagnostic Ultrasound: A New Bibliography, Human Studies Conducted in Modern China written by Jim West, a medical researcher:
“Unknown to Western scientists, the hazards of ultrasound have been confirmed in China since the late 1980s, where thousands of women, volunteering for abortion, thousands of maternal-fetal pairs, were exposed to carefully controlled diagnostic ultrasound and the abortive matter then analyzed via laboratory techniques.” (Jim West, A New Bibliography, Human Studies Conducted in Modern China) ³²
There are also some important guidelines for safe ultrasounds use that women should be aware of if they are considering having them:
Guidelines for Safe Ultrasound Use:
Ultrasounds should be used when medically indicated. (They shouldn’t be used in the first trimester in a low-risk pregnancy.)
The operator should have a high level of skill and experience and should only use minimum intensity settings.
A session should last no more than 3 minutes (5 minutes maximum)
Avoid non-medical 3D ultrasounds. They carry a potentially higher risk to baby due to the higher acoustic output required for high-definition images.
Safer and less invasive Alternatives
A fetoscope, which is a more traditional way to listen to a baby’s heart rate without the risks of ultrasounds. (This is what my homebirth midwife used to listen to my baby’s heartbeat throughout both of my pregnancies.)
A pinard horn is another alternative - This is a horn-shaped device (usually made from wood or metal). You can request for your midwife or doctor to use a fetoscope or pinard if you are looking for a less invasive alternative to ultrasounds.
A fetoscope which my midwife used to listen to my baby's heartbeat in pregnancy.
“Although ultrasound may sometimes be useful when specific problems are suspected, my conclusion is that it is at best ineffective and at worse dangerous when used as a ‘screening tool’ for every pregnant woman and her baby. […] Treating the baby as a separate being, ultrasound artificially splits mother from baby well before this is a physiological or psychic reality. This further… sets the scene for possible but to my mind artificial conflicts of interest between mother and baby in pregnancy, birth and parenting” - Sarah Buckley MD.³³
This is not to suggest that ultrasounds should not be used in cases when they are medically indicated. It is worth discussing in depth the known risks and the potential benefits with your prenatal care provider prior to having prenatal ultrasounds. Look at the bigger picture and never discount your gut instinct.
