In the previous article I talked about diet as a possible cause of autism. Now I will discuss ultrasound scans.
Sonograms were developed in the 1940s for war purposes, following earlier experiments into radar systems. The first medical ultrasonic systems appeared in the late 1940s, followed by the first use of obstetric ultrasound in 1958, when a report entitled "Investigation of abdominal masses by pulsed ultrasound" was published in the Lancet. (1 and 2)
Ultrasound scans are thought to be generally safe for the unborn baby because they use sound waves rather than radiation, but the FDA advise against "bonding" scans done for non-medical purposes, in case of unknown risk to the fetus. (3).
Ultrasound scans produce sound waves and heat that is capable of heating up body tissues. Many fetuses move away from the area where the probe has been placed and this may be because they are feeling heat.
Effect on Fetal Brain
A study in Epidemiology looked at Swedish men, one group who had been exposed to ultrasound during gestation and one group who were not, all born between 1973-1978. Of these, 6,858 men were born to mothers who had sonograms and a further 172,537 men whose mothers had not.
In the early 1970’s, sonograms were only given to women with high risk pregnancies and as the decade progressed, it began to be offered routinely to all pregnant women.
The researchers concluded:
"During the introduction phase (1973 to 1975) there was no difference in left-handedness between ultrasound exposed and unexposed (odds ratio = 1.03, 95% confidence interval (CI) = 0.91 to 1.17). When ultrasonography was offered more widely (1976 to 1978), the risk of left-handedness was higher among those exposed to ultrasound compared with those unexposed (odds ratio = 1.32, 95% CI = 1.16 to 1.51). We conclude that ultrasound exposure in fetal life increases the risk of left-handedness in men, suggesting that prenatal ultrasound affects the fetal brain."
Although being left-handed is not a problem, the study demonstrated how ultrasound can affect the brain of the developing baby. (4).
Fetal Response to Heat