Causes of Sudden Infant Death Syndrome. Statistics for Russia and Europe

Sudden Infant Death Syndrome (SVSM), also known as crib death, is the sudden, unexplained death of a baby in infancy. Such a diagnosis is made when the death of the baby remains inexplicable even after a thorough autopsy and a detailed investigation of what happened. This article will talk about this tragic phenomenon.

Definition of a concept

The aforementioned syndrome is a diagnosis of exclusion and should only be applied to cases where the infant’s death is sudden, unexpected and remains inexplicable after an adequate post-mortem investigation has been performed, including:

• autopsies (by an experienced pediatric pathologist, if possible);
• inspection of the place of death and clarification of the circumstances of death;
• studying the medical history of the baby and his family.

For example, according to the results of the study, some of these cases were caused by accidental suffocation, hyperthermia or hypothermia, neglect of the newborn’s living conditions, or some other specific cause that cannot be described as a syndrome of sudden death of infants (to what age and why it occurs, we will discuss later in the article).

Interestingly, Australia and New Zealand move on to the term “sudden unexpected death in infancy” for professional and scientific clarity. The named diagnosis is now often used instead of “sudden infant death syndrome”, as some investigators prefer to use the term “indefinite” for deaths previously considered SIDS. This change is due to a diagnostic shift in data on the causes of mortality. In addition, the US Centers for Disease Control and Prevention recently suggested that such deaths be called sudden, unexpected infant deaths.

Causes of Sudden Infant Death Syndrome

The exact causes of SHSM are still unknown. Medical scientists believe that they are based on a combination of various factors:

1. The results of the studies revealed that babies who died as a result of SIDS have a dysregulation of the autonomic nervous system caused by serotonin. This helps to increase the vulnerability of the baby to the effects of external factors, such as improper posture in a dream, overheating.
2. According to studies published in 2013, a possible cause of CBC may be the lack of an ATOH 1 gene that encodes a protein. This protein should be responsible for neuronal connections and the passage of signals from neurons that contribute to a change in the rhythm of respiration when carbon dioxide accumulates in the lymph.
3. There is a hypothesis that SIDS can be caused by the malfunctioning of the autonomic nervous system, in particular its departments associated with the respiratory system and cardiac muscle, as well as insufficient serotonin.
4. There is also a theory that the sudden death syndrome of an infant is closely related to the underdevelopment of the respiratory center, in combination with some other factors. Of no small importance in this regard is the birth of a child before the 39th week of pregnancy.

In some cases, child abuse in the form of intentional asphyxiation may be mistakenly diagnosed as SHSM. It is believed that it accounts for less than 5% of cases.

Prevention measures

By far, the most effective way to reduce the risk of SHSM is to place a child under the age of one year on his back. The fact is that sleeping on the stomach is the only risk factor for the development of SHSM, causing the least doubt. Other measures to prevent breathing problems and strangulation of the baby are:

• the use of a solid object that will separate the parent and the baby during sleep;
• lack of a soft base and pillows in the crib;
• maintaining a certain temperature during sleep;
• the use of pacifiers;
• lack of exposure to the child of tobacco smoke.

Breastfeeding and immunization can also be attributed to preventive measures. At the same time, children's monitors and other means of monitoring a child are not a sufficient measure to prevent his death.

Support for families affected by SHSM is very important, as the infant dies suddenly and without witnesses, and investigations are often underway.

Statistics

In 2015, about 19,200 described deaths occurred in the world, which, compared with 22,000 deaths in 1990, indicates a gradual reduction. According to statistics, sudden infant death syndrome was the third leading cause of death in young children in the United States in 2011.

It is also the most common cause of infant death in the world. Scientists, speaking of how old the syndrome of sudden death of infants occurs, argue that this phenomenon is observed in newborns up to a year. And about 90% of cases occur before they reach the age of six months, and most often this happens between two and four months. And more common in boys than in girls.

Risk factors

Again, the causes of sudden infant death syndrome are unknown. Although studies have identified risk factors such as sleeping a baby on the tummy, there is no unambiguous understanding of the biological process of a baby’s death or its potential causes.

It seems that social, economic and cultural factors, such as maternal education, race or ethnicity, as well as the level of earnings, influence the situation. Such death, according to doctors, occurs when an infant with a basic biological vulnerability, who is at a critical age for development, is exposed to adverse external influences. The following risk factors usually play a large role in mortality:

• Tobacco smoke. Especially dangerous for babies of mothers who smoke during pregnancy. Nicotine and its derivatives chemicals cause significant changes in the development of the nervous system of the fetus.
• Sleeping baby on his stomach or on his side. He is the most dangerous at the age of two to three months.
• Increased or decreased room temperature.
• Too much bedding, clothes, soft surfaces in the crib.
• Sharing a bed with parents or siblings. This risk is maximum in the first three months of life. If the mattress is too soft and one or several people share the baby’s bed, there is a risk of suffocation. Especially when parents in bed use drugs or alcohol or smoke.

The American Academy of Pediatrics, for example, does not recommend sharing sleep with the baby in bed, saying that this can reduce the risk of a baby's death by almost 50%. In addition, the Academy recommended safety devices - dividing frames for beds.

Abuse and SHSM

There are fatal cases that were initially diagnosed as sudden infant death syndrome, but an autopsy and investigation revealed that infants were victims of abuse or neglect by parents or guardians. As a rule, they attract especially keen attention of society and the media.

These include those when children were deliberately strangled by their parents. However, such cases, which caused high-profile articles in newspapers and television stories, are very rare, more likely an exception than a rule. Their exact frequency cannot be estimated, but perhaps they make up less than 3%.

Other features

It is still not clear whether joint sleep with breast-feeding mothers is associated with a risk of developing the syndrome described. By the way, it decreases with increasing maternal age, and it is greatest among teenage mothers.

Inadequate prenatal behavior of the mother many times increases the risk. The baby’s low birth weight is also a significant factor. So, in the USA in 1995-1998, the level of SHSM among children with a body weight of 1000-1499 g was much higher than in larger newborns.

Preterm birth increases the risk of death by about 4 times. Newborns who were born before the 37-39th week of pregnancy are more at risk of dying from sudden death syndrome. A difficult factor include heavy labor.

The average age of the sudden death syndrome of infants, as already mentioned, is from 2 to 4 months. And in any way, scientists still have not succeeded in detecting a tendency to this syndrome. Even an autopsy of the body does not give doctors a hint of the cause of death. The study of the syndrome was begun in 1951, but only in 1968 did the described medical concept appear, and such a diagnosis was first made.

According to doctors, the syndrome of sudden infant death can be caused by genetic characteristics.

Opinion of the pediatrician Evgeny Komarovsky

A well-known doctor in the country with twenty years of experience also expressed his special opinion. According to the pediatrician E.O. Komarovsky, the syndrome of sudden death of an infant does not have a direct relationship with sleep on the stomach or side.

For twenty years, he examined at least 100,000 children and faced with the syndrome described several times. Komarovsky believes that a child may die during sleep on his back from blockage of the upper respiratory tract after vomiting or regurgitation. There is such a disease as aspiration pneumonia. Aspiration is the ingress of foreign substances into the respiratory tract. When vomiting occurs in them, pneumonia occurs, which is very difficult to treat, gives a large amount of complications and is often the cause of death of the child.

Based on this, Evgeny Komarovsky believes that the practice of sleeping on the stomach is very useful. Also, in his opinion, this is just the position of medical statisticians and scientists who are trying to find connections between SHSM and sleep on their stomachs, but cannot find the real cause of death, because this relationship has not yet been fully proven.

Komarovsky states that when analyzing the problem, factors such as the type of pillow, humidity and air temperature, the number of dust accumulators, changes in atmospheric pressure, the number of people in the children's bedroom, and much more should be taken into account.

Prevention plan

How to stop being afraid of sudden infant death syndrome? There is no reliable way to prevent these deaths, but you can help your child sleep well by following the rules:

1. Sleep on the back. Put your baby to sleep on your back, not on your stomach or side. But this is not necessary when your baby is awake. It can roll in both directions.
2. It is essential that the baby’s bed is as flat as possible. Use a hard mattress and do not put your child on a thick fluffy blanket made of camel or sheep’s wool. Do not leave pillows, fluffy toys or animals in the crib. They can interfere with the breathing of a newborn baby when he falls asleep.
3. Do not overheat the child. To keep your baby warm, use a sleeping bag or sleepwear. Do not cover the baby’s head.
4. Put him to sleep in your room. Ideally, the baby should sleep in your room in a crib or crib for at least six months, and if possible, up to a year.
5. Adult beds are not safe for babies. A newborn can fall into a trap and suffocate between the lattices of the front headboard, the space between the mattress and the bed frame, or in the space between the mattress and the wall.
6. The child may also suffocate if the parent accidentally rolls over and covers the child’s nose and mouth.
7. If possible, breastfeed your baby. Breastfeeding for at least six months reduces the risk of various diseases. This is a very important preventative measure.
8. Do not place unnecessary hopes on children's monitors and other monitoring devices, which, according to advertising, reduce the risk of the syndrome, due to their inefficiency and insecurity.
9. Sucking a pacifier that is not suspended on a cord around the baby’s neck at night and during sleep can reduce the risk of developing SHSM. One caveat - if you are breastfeeding, wait until your baby is 3-4 weeks old before giving him a dummy.
10. If your baby does not like the nipple, do not force it. Try to give it the next day. If the nipple comes off the baby’s lips while he’s sleeping, don’t put it back in.
11. Give your child routine vaccinations. There is no evidence that they increase the risk of SHSM. Some evidence suggests that immunization can help prevent this syndrome.

By adhering to these recommendations, you can protect the child from this terrible sudden death. But you should not constantly panic, it is better to be attentive and caring parents and take proper care of your kids. Only in this case will you be able to protect your family from the misfortune described here.

Statistics for the Russian Federation

According to statistics, in Russia 0.50% per 1000 newborns die from sudden infant death syndrome (i.e. 5 newborns per 10,000 infants). After organizing a fund that deals with this problem, mortality decreased by 70%, but it was not possible to completely overcome this syndrome.

In 1998, Vorontsov, a doctor-researcher, gave parents of newborns and pediatricians certain recommendations on how to reliably avoid such a disaster as the infant's sudden death syndrome. All methods are specifically described in the scientific medical literature, but we have brought to your attention only the basic principles of caring for a baby.