Swedish scientists say that based on the results of a study of seven thousand men whose mothers underwent ultrasound examinations during pregnancy, they found some abnormalities in the development of the brains of the examined men.
We are not talking about pathological changes, but about an increase in cases of left-handedness: among this contingent there were one-third more left-handers than among those whose mothers did not undergo ultrasound examinations during pregnancy.
At the same time, it is noted that there is no clear evidence yet that the identified differences occurred precisely due to frequent ultrasounds. However, the data raises new questions about the fact that research methods that until recently seemed absolutely safe and had only a positive impact on pregnancy management may suddenly turn out to be not as good as we would like.
After all, an increase by a third in cases of left-handedness indicates that the ultrasound showed that the brain of one out of 50 male fetuses was affected. We are talking about boys, because it is known that the brain of boys develops somewhat longer than girls, and therefore is subject to greater dangers, especially in the second half of pregnancy.
There are at least two considerations in this regard.
Firstly, the risk has not yet been proven, since every pregnant woman in modern conditions undergoes many different studies, each of which can potentially affect her health and the development of the fetus. The number of cases where ultrasound made it possible to save the life of both the mother and the fetus, maintain a pregnancy, or prevent the birth of a very sick child in time is incalculably greater than the number of additional left-handers. So the benefits of ultrasound have been proven, but the losses are doubtful.
Second. In order to be able to statistically reliably talk about the influence of anything on a person, a fairly large period of time is required. But the studies were conducted on children who were born in the 70s, i.e. were examined using the very first generation equipment. Nowadays, third-generation ultrasound scanners are in use, which have a different radiation range, lower signal power with higher resolution, and a host of other improvements that reduce the load on the body of the mother and fetus.
Therefore, it is wrong to transfer data from the 70s to the 21st century. New research is needed to confirm or refute the negative effects of ultrasound on the fetal brain.
Any medicine or research can be beneficial or harmful - it's just a matter of dose. There are indications for conducting research when the clear benefit certainly outweighs the doubtful harm. So you should adhere to this frequency - from one study during pregnancy to the number that is justified by the interests of the woman and her child.
In addition, both doctors and women themselves should monitor what equipment is used for ultrasound - old, antediluvian or modern, with a reduced load, a certain radiation range, etc.
It is possible that carefully considered recommendations on the amount and timing of ultrasound use during pregnancy will be developed in the near future. But until this happens, act rationally: if necessary, do research.