Obstetric practices in NZ follow close on the heels of those in larger countries like the USA. Most women in NZ now have at least 4 ultrasound scans during their pregnancy with at least 2 of these being performed in the first trimester. In NZ most women access fully subsidized pregnancy/maternity care and those who pay privately for obstetric care still have their (usually much greater number of) scans publicly subsidized. The continuing increase in ultrasound scanning is greatly increasing the cost of maternity care to the NZ taxpayer with no commensurate improvement in outcomes. Like the rest of the developed world, where ultrasound is readily available, we are seeing an increase in autistic spectrum disorders and also things like tongue and lip tie. More regulation, research and consumer education is urgently needed. We hope the USA will lead the charge to ensure the safety of this overused technology.
Written as a retort to the Yale study by Ang, et all in 2006 which detected brain growth abnormalities after ultrasonic exposure…
These fellows discuss some of the dissimilarities between the Ang study using mice and actual prenatal conditions. Although it is true that the Ang study’s results are not perfectly linear, such can be expected from such a study.
* Ang noted ultrasound to cause brain growth problems at intensities an order of magnitude or so lower than modern intensities. (meaning modern prenatal ultrasound is stronger, and may have more impact)
* The thermal and mechanical indices are not great guestimations, meaning that US scanners do not accurately report risks.
* Rats are not perfect models for human brains.
I have a comment about some of the response, too. In this paper they discuss later-trimester fetal skulls to be stronger — while it is true that they do become more developed, the fetal skull is pretty soft, still.
In fact, it has similar acoustic indices as water. Adult skulls that are well ossified are much better acoustic absorbers.
I also found it interesting that Republican Joe Pennacchio had attempted to introduce legislation into the investigation of ultrasound and autism.
Cells can be damaged by diagnostic ultrasound. While I may not know much about the brain, I do know that when building the house the foundation is the most important.
Similarly, early parts of fetal development are sensitive and disturbance could have long term consequences.
If diagnostic ultrasound is capable of causing cellular damage, then the downstream effects of this definitely deserve further investigation.
To evaluate the effects of diagnostic ultrasound on villus ultrastructure of early pregnancy.
Using the electron microscopy, the effect of B-mode ultrasound and color Doppler flow image on villus of early pregnancy were studied. 46 cases of early pregnancy women were divided into five groups: Groups 1 : control group; Group II and III: 24 +/- 1 hours after exposure to B mode and color Doppler ultrasound for 30 minutes respectively; Group IV and V: 72 +/- 1 hours after exposure to B mode and color Doppler ultrasound for 30 minutes respectively.
Expansion of perinuclear space in cytotrophoblasts and syncytiotrophoblasts, enlargement of rough endoplasmic reticulum, and vacuolization in the cytoplasm were found in Group II and III.
The present study showed that the main injured sites after exposure to ultrasound were the plasma membrane and suborganelles. These changes disappeared within 3 days.
According to this study, mouse brains exposed to diagnostic ultrasound grew incorrectly. This is brain damage during development.
Developing brain cells have to migrate from a starting location to a distant one, where they link up to other cells. This study suggests that ultrasonic exposure can disrupt this, knocking cells around and leading to mis-connections.
00:00:03 To find out how to dilute a man’s knock-up sauce without permanent damage, we asked the doctor.
00:00:09 – If men are engaging in unprotected sex, they might want to be temporarily infertile.
00:00:15 announcer: SO How can they do that?
00:00:17 A man could try blasting his sack with an ultrasound machine.
00:00:21 According to the university of north carolina, zapping a bro’s crotch with ultrasound waves for just ten minutes could kill his sperm for up to six months!
00:00:31 But there’s a catch.
00:00:32 Hitting some high notes on his tweeter can close his sperm tube permanently.
00:00:37 both: AH!
I saw this recently on SpikeTV and it had me cracking up hard enough that I had to share it.
I visited the ultrasound labs at UNC Chapel Hill personally and met several people who worked there. I am concerned that ultrasound use on gonads would change hormone levels in adults. In the literature, there is evidence that ultrasound exposure to rat gonads alters their testosterone levels … reference: http://revistas.um.es/hh/article/viewFile/130341/121361
In this paper, Dr. Manuel F. Casanova (referenced in an earlier post) and Emily Williams review side effects and shortcomings in ultrasound safety regulation.
It’s pretty point on.
For those just joining us – a teratogen is something, like a chemical or environmental exposure that can affect fetal development. You know, like alcohol use during pregnancy.
Historically, the FDA has allowed several things through the nets into widespread circulation that had serious side effects. Thalidomide, X-Ray for fetal scanning, among other things.
There are many side effects of ultrasound that appear harmful on a small scale, but how they affect development has not been rigorously studied. There are, however, a great many deficits in safety regulations surrounding ultrasound that need to be addressed. For example…
1. Ultrasound machines are not required by law to be upkept. Old equipment becomes defective, leading to worse pictures. Worse pictures means more ultrasound must be used for a good image.
2. There are no limits to the number of scans allowed to be prescribed. This, in essence, rewards practitioners to believe ultrasound is not risky because of high healthcare costs. Each scan can be a $1000~ payout, for only a few cents of KY Jelly. …and a nurse can do it, since it is legal for unspecialized people to perform ultrasounds.
3. Practitioners do not record how much ultrasound is used, so proper dose-based risk assessment cannot be performed using modern intensities.
And many more …
*note: the calf in the picture is not two headed because of ultrasound.
When focused with sufficient intensity, ultrasound causes powerful upwellings inside fluid mediums. These upwellings can cause gases to nucleate, further creating small microbubbles, called cavitation bubbles.
With continued exposure, these bubbles will gather gas until they reach a critical level where their structure cannot support the amount of pressure around them and so they implode.
The implosion creates a superheated jet of gas reaching 10,000 degrees Celsius and a shockwave of 300 times atmospheric pressure. It destroys fat if aimed at fat.
It also occurs in submarine propellers from them spinning under water. The picture shown is of cavitation damage to metal. Very destructive force.
This can also be used to treat cancers. The possibility exists also to create lesions in beneficial places, such as in the treatment of Parkinson’s disease with US (which will have to wait for another post). Kind of like internal acupuncture.
Cavitation is not a very common event in the fetus at lower levels of ultrasound exposure but the threat has been noted in literature. Keeping ultrasound as low as possible would prevent against it. However, higher intensities allowed in fetal imaging are potentially cavitating.