Sudden infant death syndrome (SIDS) is a particularly dramatic event for the affected family. An otherwise seemingly very healthy infant dies suddenly and without any prior symptoms. Especially at risk are infants in their 2nd to 4th month of life, with SIDS most often occurring during sleep. In the last decades, studies have identified the prone position, overheating and exposure to nicotine as risk factors but the actual mechanism leading to death has not been clearly identified. Many scientists believe that the involuntary “autonomic nervous system” (which controls organ functions) plays a crucial role and that death is ultimately brought on by circulatory failure.
In recent years, several scientific works have shown that using a pacifier can reduce the risk of SIDS. However, they have not (yet) been able to determine the exact mechanism of action. Possible explanations mention among other things, the airway is kept open more effectively, better removal of oropharyngeal pathogens and higher responsiveness to threatening situations. However, there is still no scientific evidence of this. This is why international research continues to deal with the question of just how a pacifier works in reducing the risk of SIDS.
A new study published in the prestigious scientific journal Sleep Medicine examined the relationship between pacifier use and cardiovascular regulation. For the study, infants who used pacifiers and those who did not use them during their first 6 months of life were brought to a sleep laboratory at three different ages (2-3 weeks, 2-3 months and 5-6 months). In order to identify possible differences in body position, the babies were examined both in the supine and prone position. In addition to various other factors such as brainwave activity (EEG), breathing and oxygen supply, various circulatory parameters (incl. pulse and blood pressure) were constantly recorded. Afterwards, the results of the two groups (pacifier users vs. non- pacifier users) were statistically compared.
This showed that at the ages of 2-3 weeks and 5-6 months, the blood pressure for pacifier users in the prone position was higher in the phases, where they did not suck on the pacifier. Additionally, increased heart rate variability (greater bandwidth of pulse rate frequency) was noted at the age of 2-4 weeks. Sucking on a pacifier also resulted in an increased heart rate variability and a simultaneous increase in blood pressure variability, both of which we consider to be increased “sympathetic activity”.
This study showed for the first time, that using a pacifier affects the “autonomous functions”. Increased sympathetic activity can be regarded as a readiness to deal with threatening situations in the sense of a "fight or flight" response. Even if this study does not sufficiently explain the pacifier’s working mechanism of action, it should serve as an incentive for continued research in this direction.
The risk of SIDS can be significantly reduced if, during their first months of life, babies are laid on their back for sleeping, breastfed, kept from becoming too warm and protected from exposure to nicotine. Furthermore, the protective effect of pacifier use has been noted in other studies, which is why several professional organizations (including the American Academy of Pediatrics) have included this in their recommendations.