Is an Obstetric Ultrasound Truly Safe?
Part 2 of Fetal Ultrasounds
If you are pregnant, an obstetric ultrasound - or more- will be offered to you.
You have been told for years that fetal ultrasounds are perfectly safe.
Then again, for decades we were told that x-rays - while pregnant - were safe...
...new research is now saying that an obstetric ultrasound may not be as safe to your baby as previously believed.
Obstetric Ultrasound Related To Autism?
This study was published in 2006.
Dr. Pasko Rakic - chair of Yale School of Medicine's Department of Neurobiology - announced the results of a study in which pregnant
mice underwent various durations of ultrasound.
The results: The brains of the offspring showed damage consistent with that found in the brains of people with autism.
The research, funded by the National Institute of Neurological Disorders and Stroke, also implicated obstetric
ultrasound in neurodevelopmental problems in children, such as dyslexia, epilepsy, mental retardation and schizophrenia, and
showed that damage to brain cells increased with longer exposures.
Dr. Rakic's study - which expanded on a 2004 research with similar results - is just one of many animal experiments and human studies
conducted over the years indicating that obstetric ultrasound can be harmful to unborn babies.
Parents must seriously consider the possible consequences of both routine and diagnostic use of obstetric ultrasound, as well
as Dopplers - a device used during prenatal exams to listen to your baby's heartbeat***, which may be
neither non-invasive nor safe.
*** Midwives are trained to use another device called a fetoscope which is NOT harmful to your baby. It is a bit like a
stethoscope.
The only drawback is that you cannot hear your baby's heartbeat - although many fetoscopes can be fitted with cords long enough for you to listen.
If pregnant women knew all the facts, would they choose to expose their unborn babies to a technology that - despite its increasingly
entrenched position in modern obstetrics - has little or no proven benefit?
Would you?
Ultrasound Equipment: Obstetric Ultrasound Waves
The problems with an obstetric ultrasound are sound and heat.
One challenge that ultrasound operators face is keeping the transducer positioned over the baby's part that he is trying to observe.
When babies move away from the stream of high-frequency sound waves, they may be feeling vibrations, heat or both.
The FDA - which is by no means conservative - warned in 2004:
"Ultrasound is a form of energy, and even at low levels, laboratory studies have shown it can produce physical effect in tissue, such
as jarring vibrations and a rise in temperature."
This is consistent with research conducted in 2001 in which an ultrasound transducer aimed directly at a miniature
hydrophone placed in a woman's uterus recorded sound "as loud as a subway train coming into the station."
According to research, a rise in temperature of fetal tissue can cause significant damage to a developing baby's central nervous system.
Elevated maternal or fetal body temperatures have been shown to result in birth defects in offspring.
Understanding what happens when the baby's temperature increases - whether caused by an elevation in maternal core temperature or by the
more local effect of ultrasound - is the key to appreciating obstetric ultrasound risks.
Your body temperature varies throughout the day due to various factors such as circadian rhythms, hormone fluctuations and physical exertion.
While you may have up to 1.5 F in each direction of what is considered a "normal" core temperature, the overall average among people is 98.6 F.
An increase of only 1.4 F to 100 F can cause headaches, body aches and fatigue, enough to get the individual excused from work.
A temperature of 107 F can cause brain damage or death.
A core temperature of about 98.6 F is important because that is the point at which many important enzyme reactions occur.
Temperature affects the actual shape of the proteins that create enzymes, and improperly shaped proteins are unable to do their jobs correctly.
Factors such as the amount of heat or duration of exposure increase, enzyme reactions become less efficient until they are permanently
inactivated, unable to function correctly even if the temperature returns to normal.
Because temperature is critical to proper enzyme reactions, the body has built-in methods to regulate its core temperature.
For instance:
when your temperature is too low, shivering warms it up
when it is too high, sweating wicks off the heat.
For obvious reasons, unborn babies cannot cool off by sweating.
However, they have another defense against temperature increases:
Each cell contains something called heat shock or HS proteins that temporarily stops the formation of enzymes when temperatures reach dangerously high levels.
Complicating the issue is the fact that an obstetric ultrasound heats bone at a different rate than muscle, soft tissue or amniotic fluid.
Furthermore, as bones calcify, they absorb and retain more heat.
During the third trimester, the baby's skull can heat up 50 times faster than its surrounding tissue, subjecting parts of the
brain that are close to the skull to secondary heat that can continue after the ultrasound exam has concluded.
Elevated temperatures which temporarily affect the mother can have devastating effects on a developing baby.
A 1998 article in the medical journal Cell Stress and Chaperones reported that:
"The HS response is inducible in early embryonic life but it fails to protect embryos against damage at certain stages of development."
The authors noted, "With activation of the HS response, normal protein synthesis is suspended but survival is achieved at the expense
of normal development."
What Does A Study On Mice Have To Do With My Baby?
It is actually very significant.
A study conducted at Cornell in 2001 proved that brain development proceeds in the same manner:
"Across many mammalian species, including human infants."
The team found "95 neural developmental milestones" that helped them pinpoint the sequence of brain growth events in different species.
Therefore, if repeated experiments show that elevated heat caused by ultrasound damages fetal brains in rats and
other mammals, one can logically assume that it can harm human brains as well.
My Doctor Says An Obstetric Ultrasound Is Safe.
Well...the FDA disagrees.
In fact, the FDA - as well as professional medical associations - knows that obstetric ultrasound can be dangerous to humans, which is why
they have consistently warned against the non-medical or "keepsake" obstetric ultrasound portrait studios that have cropped up in
malls throughout the country.
The risks to the baby are potentially higher in commercial (i.e. 4-D obstetric ultrasounds) enterprises due to the higher acoustic
output required for high-definition images, a potentially long session - as technicians hunt for suitable images - and the employment
of ultrasound operators who may have no medical background or appropriate training.
Quite simply, if obstetric ultrasound can injure babies, it can cause the same damage whether done for routine, diagnostic or "entertainment" purposes.
Autism, Genetics And Twins Ultrasound Studies
What does obstetric ultrasound have to do with autism? According to some recent studies...a lot!
Recently researchers linked two mutations of the same X chromosome gene to autism in two unrelated families, although they do
not yet understand at what stage these genes were damaged.
Because sibling and twin studies show a higher prevalence of autism among children in families with one autistic child, geneticists
expected to find inherited factors, but despite millions of dollars invested in the search, no clear explanation indicates that autism is inherited.
Perhaps scientists need look no further than at the heat effects of fetal ultrasound for many answers.
If fetal ultrasound is responsible for some cases of autism, it stands to reason that if one twin were autistic, the other
would have a high probability of being affected, since both would have been exposed to ultrasound at the same time.
In both identical
and fraternal twins, one twin could be more severely
affected than the other if he or she happened to take the brunt of
the heat or sound waves.
In the case of fraternal twins, since autism strikes males between three to five times more often than females, the sex of the twins
also could make a difference in outcome.
A 2002 study showed that simply being a twin substantially increased the likelihood of autism, making twinning a risk factor.
Could this increased twin risk factor have to do with the practice of giving mothers with multiple gestations more ultrasounds
than those expecting a single baby?
While not discounting the role genetics may play in autism, the possible impact of prenatal ultrasound deserves serious consideration.
This Is Not Headline News: Autism Is On The Rise!
There is indeed a global autism epidemic.
Statistics on the increase of autism worldwide among industrialized nations show that it has emerged in
just the last few decades across vastly different environments and cultures.
What do countries and regions with climates, diets and exposure to known toxins as disparate as the US, Japan,
Scandinavia, Australia, India and the UK have in common?
No common factor in the water, air, local pesticides, diet or even building materials and clothing
can explain the emergence and relentless increase in this serious, life-long neurodevelopmental disorder.
What all industrial countries do have in common is the quiet yet pervasive change in obstetrical care:
All of them use routine prenatal ultrasound on pregnant women.
In countries with nationalized healthcare, where virtually all pregnant women are exposed to ultrasound, the autism rates
are even higher than in the US, where due to disparities in income and health insurance, some 30 percent of pregnant women do not yet
undergo ultrasound scanning.
What About Obstetric Ultrasound And Birth Defects?
One of the most popular non-medical uses of fetal ultrasound is to determine the sex of the baby.
Could this have a connection to the increase in birth defects involving the genitals and urinary tract?
The March of Dimes says that:
"These types of birth defects affect "as many as 1 in 10 babies," adding that "specific causes of most of these conditions is unknown."
Following this line of thought, consider what other parts of the body are scrutinized by ultrasound technicians, such as the heart,
where serious defects have soared nearly 250 percent between 1989 and 1996.
Sadly, the list of unexplained birth defects is not a short one.
In light of what is emerging about obstetric ultrasound, scientists should take another look at all recent trends, as well as
the baffling 30% increase in premature births since 1981, now affecting one in every eight children, with many showing subsequent neurological damage.
Although many claim that obstetric ultrasound benefits outweigh the risks, that statement has no basis and much evidence is to the contrary.
A large randomized trial of 15,151 pregnant women, conducted by the RADIUS Study Group, found that in low-risk cases, high-risk
subgroups and even in cases of multiple gestations or major anomalies, the use of ultrasound did not result in improved outcome in the pregnancies.
The argument that ultrasound is either reassuring to the parents or provides an early opportunity for bonding pales in the face
of the possible risks that are emerging as new data become available.
Parents and health practitioners may not be able to easily turn away from this window on the womb and resume more
traditional practices in obstetrics and midwifery.
However, with the disturbing trend in autism and other equally troubling, unexplained birth-related trends, it does not
make sense to blindly employ a technology that is not reliably safe for unborn babies.
Obstetric Ultrasounds Unsafe?
The idea that an obstetric ultrasound can be hazardous is not new.
The World Health organization stated:
The National Institutes of Health - NIH - held a conference assessing obstetric ultrasound risks, it reported that when birth defects occurred,
the acoustic output was usually high enough to cause considerable heat.
Despite these findings of in 1993 the FDA approved an eight-fold increase in the potential acoustical
output of ultrasound equipment, greatly increasing the possibility of disastrous pregnancy outcomes caused by overheating.
Can the fact that this increase in potential thermal effects happened during the same period of time the incidence of
autism increased nearly 60-fold be merely coincidental?
The Dangers Are Increasing:
The following changes have made the field of prenatal ultrasound riskier than ever:
The number of ultrasound scans conducted during each pregnancy has increased, with women often receiving two or more scans even in low-risk situations.
Women in "high-risk" situations may receive many more scans - which, ironically, may raise their risk.
The range of time within an embryo or fetus's development when an obstetric ultrasound is performed has extended to very early in the first
trimester and continues into the third trimester, right up to delivery.
Fetal heart monitors that are used prior to delivery - sometimes for hours - have not been shown to reduce neurological problems and may increase them.
The development of the vaginal probe, which positions the beam of sound much closer to the embryo or fetus, may put it at higher risk.
The use of Doppler ultrasound - which is used to study blood flow or to monitor the baby's heartbeat - has increased.
According to the 2006 Cochrane Database of Systematic Reviews:
"Routine Doppler ultrasound in pregnancy does not have health benefits for
women or babies and may do some harm."
We can understand every mother's desire to make sure their baby is well.
Yet, in light of the evidence, can we justify scan after scan when we know it is not without consequences?
Leave a comment.
Read others' comments.
Obstetric Ultrasounds: Reviews
Any thoughts? A story of your own? Share with us!
|
