Humans are equipped with various reflexes to help them survive during pregnancy and during and after childbirth. Among these is the Moro reflex. In infants, this ensures the first breath after birth and serves as a startle reflex during the first months of an infant’s life.
What is the Moro reflex?
The Moro reflex ensures the first breath in the infant after birth and serves as a startle reflex in the first months of an infant’s life. The Moro reflex was first described and named by German pediatrician Ernst Moro in 1918. This reflex is a reaction that is triggered quite involuntarily by a stimulus. It is the newborn child’s reaction to a possible threat, such as falling on its back or being suddenly and rudely put down. The Moro reflex is expressed in two phases. In the first phase, the child jerkily stretches out both arms and legs, opens its hands and spreads its fingers. At the same time, it puts its head in the neck so that the upper body falls slightly backwards. Then he opens his mouth to inhale and freezes briefly in this position. The second phase follows with the pulling back of arms and legs. It now clenches its hands into fists, pulls its head to its chest and exhales. The child may then cry out loudly. The reflex is most pronounced in the first weeks of a newborn’s life. Over the next few months of life, the infant’s nervous system matures, so the frequency and intensity of the reflex decreases more and more. From the third month, it occurs less frequently and only very weakly, and disappears completely after the sixth month of life at the latest. In young animals of great apes the reflex has another meaning. They are carried around by their mother all the time. As soon as the mother moves, the Moro reflex is activated in the ape cubs. They clutch the mother very tightly and put their head back slightly to prevent them from falling off the mother. For this reason, the Moro reflex is also called the clasp reflex or the clutch reflex in technical language. Because this reflex also occurs in the first months of a human infant’s life, researchers in evolutionary biology suggest that we were once baby carriers as well.
Function and task
The Moro reflex is a highly complex response of the body that is activated by the interaction of all the senses (vision, hearing, touch, and balance). In humans, the Moro reflex forms as early as the ninth week of pregnancy. Immediately after birth, it plays a vital role for the human child: it ensures that the windpipe is opened. In this way, it stimulates the newborn to take its first breath and protects it from suffocation. Over the next few months of life, the reflex also serves to remind parents to be careful and gentle with their newborn. After all, the child is not yet able to hold its head up on its own. And since the reaction seems like an uncontrolled movement, and many babies cry out loud when this happens, parents are often very frightened. And in fact, the reflex is also very unpleasant for the baby, because the little body goes through a lot during this time: The stress hormones adrenaline and cortisol are released, the blood sugar level drops sharply and the heart rate increases rapidly. However, the reflex is a completely normal reaction of the body and is part of early childhood development.
Diseases and ailments
When the Moro reflex is triggered very frequently in the first few months after birth, the body produces more stress hormones. These disrupt the infant’s immune activity, which is not fully mature anyway. As a result of a weakened immune system, infections or respiratory diseases occur more frequently. From the fourth month of life, the Moro reflex should slowly begin to regress. As part of the infant’s neurological development, it is replaced by the startle reflex, which persists into adulthood. For early childhood reflexes, the following is true: they develop to a peak, then ebb and eventually disappear. As the early childhood reflexes regress, gross and fine motor skills also mature. There are also reflexes that do not actually disappear, but rather become integrated into a more complex reflex. Normally, the development of reflexes is the same for every child. The nervous system is not mature until the child has shed all early childhood reflexes within the first twelve months of life.However, if disorders occur during this development, then the children may later develop neurological disorders such as ADHD and hypersensitivity. Specifically, the developmental disorder of the Moro reflex can lead, for example, to the child initially spreading out its arms when falling and the support reaction being delayed. As a result, he or she injures himself or herself much more often than other children. Due to the overproduction of stress hormones, they also absorb too much unnecessary information from their environment, which they are unable to process. The constant overstimulation can ultimately lead to concentration problems and thus also to poor social behavior on the part of the children. They also have difficulty behaving appropriately in new situations. Only a regulated daily routine and a familiar environment can give them security. Even in adulthood, the restriction can remain, so that the lives of those affected are partly characterized by panic attacks and anxiety neuroses.
