Preterm infant showed better object handling skills in a neonatal intensive care unit during silence than with a recorded female voice

Maternal Voice and Tactile Stimulation Modulate Oxytocin in Mothers of Hospitalized Preterm Infants: A Randomized Crossover Trial

Prematurity is a major risk factor for perinatal stress and neonatal complications leading to systemic inflammation and abnormal mother-infant interactions. Oxytocin (OT) is a neuropeptide regulating the inflammatory response and promoting mother-infant bonding. The release of this hormone might be influenced by either vocal or tactile stimulation. The main objective of the current randomized, crossover, clinical trial was to assess the salivary OT/cortisol balance in mothers following the exposure of their baby born preterm to two types of sensorial interventions: maternal voice without or with contingent tactile stimulation provided by the mother to her infant. Among the 26 mothers enrolled, maternal voice intervention alone had no effect on OT and cortisol levels in the mothers, but when associated with tactile stimulation, it induced a significant increase in maternal saliva oxytocin (38.26 ± 30.26 pg/mL before vs 53.91 ± 48.84 pg/mL after, p = 0.02), particularly in the mothers who delivered a female neonate. Maternal voice intervention induced a significant reduction in cortisol and an increase in OT levels in mothers when the maternal voice with a tactile stimulation intervention was performed first. In conclusion, exposure to the maternal voice with a contingent tactile stimulation was associated with subtle changes in the maternal hormonal balance between OT and cortisol. These findings need to be confirmed in a larger sample size and may ultimately guide caregivers in providing the best intervention to reduce parental stress following preterm delivery.

NICU sensory experiences associated with positive outcomes: an integrative review of evidence from 2015-2020

To inform changes to the Supporting and Enhancing NICU Sensory Experiences (SENSE) program, studies investigating sensory-based interventions in the NICU with preterm infants born ≤32 weeks were identified. Studies published between October 2015 to December 2020, and with outcomes related to infant development or parent well-being, were included in this integrative review. The systematic search used databases including MEDLINE, Cumulative Index to Nursing and Allied Health Literature, the Cochrane Library, and Google Scholar. Fifty-seven articles (15 tactile, 9 auditory, 5 visual, 1 gustatory/olfactory, 5 kinesthetic, and 22 multimodal) were identified. The majority of the sensory interventions that were identified within the articles were reported in a previous integrative review (1995-2015) and already included in the SENSE program. New evidence has led to refinements of the SENSE program, notably the addition of position changes across postmenstrual age (PMA) and visual tracking starting at 34 weeks PMA.

Parental Book-Reading to Preterm Born Infants in NICU: The Effects on Language Development in the First Two Years

Background: After preterm birth, infants are at high risk for delays in language development. A promising intervention to reduce this risk is represented by the exposure to parental voices through book-reading in Neonatal Intensive Care Units (NICU). This study investigated the possible advantages of book-reading to preterm neonates during their NICU stay on their subsequent language development. Methods: 100 families of preterm infants were recruited. The parents of 55 preterm infants (Reading Group) received a colored picture-book on NICU admission and were supported to read to their neonate as often as possible and to continue after hospital discharge. Forty-five infants (Control Group) were recruited before the beginning of the intervention. Infant language development was assessed with the Hearing and Language quotients of the Griffith Mental Development Scale at the corrected ages of 3, 6, 9, 12, 18 and 24 months. Results: Regardless of group membership, Hearing and Language mean quotients decreased between 9 and 18 months; nevertheless, this decrease was considerably reduced in the Reading group, compared to the Control Group. Conclusions: Reading in NICUs represents a suitable intervention that could positively influence language development and parent-infant relationships in preterm children. The study findings support its implementation as a preventive measure.

Influence of swaddling on tactile manual learning in preterm infants

BACKGROUND AND AIM

Swaddling is a well-known technique in developmental care programs as there is some evidence that swaddling is an appropriate stress-reducing method for preterm infants in the NICU. However, no experimental study has investigated the influence of swaddling in a learning context. This study aimed to assess the impact of swaddling on tactile manual abilities in preterm infants.

METHODS

Two phases were introduced for all infants: habituation (successive presentation of the same object, prism or cylinder in the left hand), followed by discrimination (presentation of a new-shaped object). The infants were assigned to one of the two conditions (swaddled; non-swaddled).

RESULTS

Forty preterm infants were included (between 28 and 35 weeks' postconceptional age). First, swaddled and non-swaddled infants exhibited similar tactile habituation abilities. However, all infants needed more time and more trials to habituate to the cylinder than to the prism. Second, they all exhibited an effective discrimination, but the importance of the increase in holding time for the new-shaped object varied according to the habituated-shape and the condition. Moreover, stress intensity was higher in non-swaddled infants during tactile exploration. Finally, infants with greater previous swaddling experience during the week preceding the test took more time and more trials to habituate to the object, regardless of the condition.

CONCLUSION

Swaddling preterm infants during sensory learning did not influence the tactile memorization process but would improve the use of their attentional resources. Swaddling seems to provide favorable conditions for sensory learning by improving attention to tactile stimuli.

CLINICAL TRIAL REGISTRATION

This trial, EMMASENS, has been registered at www.clinicaltrials.gov (identifier NCT04315428).