Influence of odorants on preterm and term infants during neonatal intensive care: Overview and perspectives

Olfactory cues play a crucial role in peri- and postnatal development and are thought to be involved in basic processes, like parent-child bonding or the establishment of the breastfeeding relationship. These processes are highly important for the physical and mental health of the developing child. However, little attention has been given to monitoring and maintaining the olfactory environment of preterm (PI) and term (TI) infants in the hospital. This environment differs fundamentally from that of healthy neonates because the patients are exposed to odors from clinical interventions while the natural olfactory input is limited. In this article, we summarize examples of how PI and TI respond to olfactory signals and how olfactory stimulation can positively influence feeding, stress, and pain management or even stabilize breathing. Although different studies have investigated the positive effects of maternal odors and demonstrated that PI and TI respond highly sensitively and distinctly to them, hardly any comparable studies exist for paternal odors. Also, the knowledge about the role of other natural or artificial odorants is very sparse. Future work should focus on investigating the role of these odorants and on optimizing olfactory stimulation strategies using objective odor analysis techniques.