Medical expert of the article
New publications
Why are downsized babies born?
Last reviewed: 05.07.2025
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Down syndrome, according to doctors, is a pure genetic accident. Why are children born with Down syndrome? What characterizes this deviation and can it be detected in the early stages of pregnancy?
What is Down syndrome?
Down syndrome is also called trisomy involving chromosome 21. This is one of the forms of gene pathology, when the genetic material contains one extra chromosome instead of the required 46. Generally, chromosomes are paired, but in place of the 21st pair, there are three chromosomes instead of two.
Down syndrome was first discovered and described in 1866 by the English doctor John Down, so the pathology was named after him. Much later, in 1959, the French geneticist Jerome Lejeune continued his work, discovering that this syndrome and the innate number of chromosomes in a child are closely related. The word "syndrome" implies a set of certain features and characteristics.
Since an additional chromosome is not typical for humans, it provokes a certain developmental delay: a slowdown in the physical and, most importantly, mental development of the child.
How common are children born with Down syndrome?
According to medical data, the mother's age can affect the probability of having a child with Down syndrome. The probability of having a child with this pathology is higher the older the mother. According to statistics, the probability of having a child with Down syndrome in mothers aged 20-24 is 1: 1562. At the age of 35-39, this figure reaches 1:214, and if the mother is over 45, the probability of having a child with Down syndrome reaches 1:19.
According to medical reports, the risk of having a child with Down syndrome is highest if the mother is under 35. But this is not due to genetic pathologies, doctors say, but because women give birth most often at this age. As for men, their risk of having a child with Down syndrome increases after 42 years. This is explained by the quality of sperm, which is significantly reduced.
Every child in 700 on Earth is born with Down syndrome every year, according to WHO. Both girls and boys can be born with this pathology with equal probability. Moreover, the parents can be absolutely healthy – both mom and dad.
[ What do parents do when they find out that they will have a child with Down syndrome?
Most often, mothers terminate pregnancies. According to research from 2002, up to 93% of pregnancies were terminated in Europe due to the discovery of Down syndrome in unborn children. There is also data that shows that over 7 years of research, it was discovered that at least 92% of women terminated pregnancies after learning that they were carrying a child with Down syndrome.
According to statistics, more than 2.5 thousand children with this syndrome are born in Russia every year. More than 84% of parents abandon these children in the maternity hospital, giving them up. In most cases, medical personnel not only support them, but also give positive recommendations.
Why do children with Down syndrome appear?
According to modern research on Down syndrome, conducted just a couple of years ago, it was proven that this pathology can be caused not only by the presence of an extra chromosome during the formation of the embryo, but also by all sorts of accidents during pregnancy. An extra chromosome can also appear due to the incorrect formation and development of sex cells.
Neither the behavior nor the lifestyle of the mother and father affect the development of this pathology. The circumstances of the surrounding world, such as weather, environmental factors, and temperature conditions, do not affect the formation of an embryo with Down syndrome.
Early diagnosis of a fetus with Down syndrome
Early diagnostics of children with Down syndrome, not yet born, is possible and accessible to every family. It can be done in the early stages of pregnancy. The main diagnostic methods are the biochemical screening method of the chorion and the ultrasound method. The embryonic membrane, which contains chorionic villi sensitive to various vibrations, is the material for the study. Doctors take a sample of the placenta or amniotic fluid with a large thin needle and do the analysis. The analysis of amniotic fluid is called amniocentesis.
These diagnostic methods are considered quite risky. With these diagnostic methods, there is a high risk of miscarriage or damage to the placenta.
Birth of a child with Down syndrome
When a child is born, Down syndrome can be determined in a newborn by its characteristic features. The weight of such a child is less than usual, the eyes are narrow, the bridge of the nose is too flat, the mouth is constantly slightly open. But in order to be sure that the child was born with Down syndrome, additional chromosome tests must be carried out.
A child with Down syndrome has a number of associated diseases, such as heart disease, poor eyesight, hearing and speech disorders. The opinion that children with Down syndrome have mental disorders is not entirely true. These children can talk, write, draw, fix devices, read, play various musical instruments. Communication is important for such children, but not isolated, but in a group of children.
Children with Down syndrome have a very hard time communicating fully, but you shouldn't separate them from people. They have a hard time doing analytical work, but such children may have abilities that normal children don't have. They may have phenomenal memory, particularly visual memory. They can remember large amounts of information, both musical and textual.
Why are children with Down syndrome born? Nature plans for some of these children to live among us and often stand out for their extraordinary abilities. Nothing happens by chance. And it is not only a matter of the possible presence of an extra chromosome, but also of the pricelessness of human life, which fulfills its purpose in this world.