Comparison of Two Early Treatments for Premature Babies and Their Effects Over Time

According to a report published by the World Health Organization (WHO) in 2023, 13.4 million infants were born prematurely worldwide in 2020. In France, the 2022 INSERM (Institut national de la santé et de la recherche médicale) report indicates that between 2016 and 2020, the rate of premature births represented 7% of all births and has remained stable for two decades. Prematurity has a significant medical and economic impact in France. It is estimated that the total cost of care (inpatient and outpatient) during the first year of life is approximately €82,000 for infants born before 32 weeks of gestation, compared to an average of only €2,500 for full-term infants. Depending on the degree of prematurity, the outcome for children will vary. Accordingly, the EPIPAGE 2 (Etude épidémiologique sur les petits âges gestationnels) cohort found that 27% of infants born extremely premature, 19% of infants born very premature, and 12% of infants born moderately premature have severe or moderate developmental difficulties (intellectual delay, coordination or neurosensory disorders) during childhood, compared to only 5% of infants born at term. More than a third of premature children also have milder disorders such as neurodevelopmental, behavioral, or sensory disorders. These sensory integration disorders are caused in particular by infections due to the context of premature birth, as well as by the sensory environment of neonatal units, which can lead to central nervous system impairments. Indeed, neonatal units are now known to be "dystimulating" for newborns. Whether due to invasive care, the high-noise environment, antiseptic odors, or high light levels, neonatal units do not provide the same developmental conditions as the intra-uterine environment. As preterm infants do not yet have mature sensory systems, these sensory conditions are greatly disturbing since they cannot be optimally integrated at the cerebral level. These repeated dystimulations induce short-term effects on behavior and physiology, as well as long-term effects such as hypersensitivity, malformations of the sensory cortex, and, more broadly, sensory integration disorders. These cortical alterations manifest as a loss of white matter and a reduced brain size in several brain regions. Several studies have highlighted a link between these sensory integration disorders in premature infants and impaired cognitive development during childhood. Among the approaches implemented in recent years to limit the consequences of prematurity, controlling the sensory environment and providing sensory care for infants are of fundamental importance. To date, there are numerous official recommendations on the subject, such as the document published by the "Care Environment" commission, the report by the "First 1000 Days" commission and that of the "Care Environment" commission, which recommends adapting the hospital environment of neonatal units and taking into account the sensory needs of premature babies. Among the best-known programs for neonatal environmental management is NIDCAP (Newborn Individualized Developmental Care and Assessment Program), which aims to limit sensory dystimulations and adapt care for premature newborns in accordance with their sensory needs. This program recommends that ceiling lights should not exceed a certain brightness threshold and that dimmable ceiling lights should be used. In addition, the noise level of scopes should be reduced whenever possible, care should not be provided while infants are sleeping so as to respect their sleep, and sugar may be administered to limit pain perception. It is also recommended that babies be positioned in their cribs using swaddling blankets, in order to replicate the flexed position that they adopted in their mother's womb. Health authorities also insist on the use of developmental care strategies focused on the sensory abilities of premature infants, making this a key factor in promoting brain plasticity in premature infants. The French National Authority for Health (HAS) also recommends early intervention by psychomotor therapists as a preventive measure on a sensory-perceptual-motor level from the neonatal period onwards. Multisensory care programs have been developed, but only a small proportion are practiced in developmental care in French neonatal units. Sensory-focused treatments mainly center on massage, such as the International Association of Infant Massage program (IAIM), or music therapy. Another commonly used practice is the Kangaroo method, where the parent has skin-to-skin contact with their child. ATVV (Auditory, Tactile, Visual, and Vestibular stimulation) therapy, also known as H-HOPE, is one of the scientifically validated therapies that is not used in France, making it of interest here. In this multisensory treatment, parents are directly involved as they are the ones who implement it, with the support of either pediatric nurses in the US or psychomotor therapists in France. Currently, large-scale training of healthcare professionals is being conducted in the US in order to generalize and systematize this treatment in all neonatal units. This care involves a multisensory stimulation protocol carried out by parents on a daily basis from the moment the premature infant is in stable condition. During 15-minute sessions comprising three codified phases, the parent simultaneously stimulates several of the infant's senses in a coordinated manner, while respecting the infant's rhythm. It is thus possible to distinguish between a phase of oralization/eye contact, a phase of oralization/massage, and a phase of oralization/rocking. The infant's physiological constants and behavioral manifestations are closely monitored. Numerous beneficial effects have been demonstrated, such as a positive effect on infants' alertness, sucking coordination, weight gain, tonic regulation, stress levels, and neurovegetative variables. The treatment also has a positive impact on parents, who are better able to understand the signals emitted by their baby and are more responsive to signs of hunger or sensory dystimulation. However, the link between multisensory care and motor development in premature infants remains understudied. For instance, it is not known when premature infants receive multisensory care, how this affects their motor skills and sensory integration before and after their term age. To date, the mechanisms involved in the link between multisensory integration and movement quality in premature infants remain unexplored. From a methodological point of view, most studies use a control group consisting of full-term infants or premature infants receiving only standard care: the specific effect of "care" is therefore not studied. PREMOTSENS overcomes these methodological limitations by using two comparison groups. The first intervention control group consists of premature infants receiving "Parental Singing" care, where the parent must sing to the infant, and the second control group consists of full-term infants. The choice of a comparison group receiving "Parental Singing" care was made in accordance with the literature. Numerous meta-analyses have shown that singing by parents, with mothers often being the most studied, has benefits for premature infants, including stabilization of certain physiological parameters, more consistent behavior, increased food intake, and analgesic effects during care. Effects on the parent have also been observed, with a decrease in maternal anxiety and improved parent-child synchrony. However, since singing does not require motor skills, no benefits of this treatment have been observed on the motor development of premature infants in either the short or long term, except in a very recent study. This makes the Parental Singing group an ideal comparison group for our experimental group benefiting from the ATVV protocol. Furthermore, most studies have focused on the short-term effects of treatment. In order to provide a more comprehensive analysis, our study will be conducted on two different time scales: a short-term analysis (studying the effects from 34 weeks of gestation to 40 weeks of gestation) and a long-term analysis (studying the effects up to 6 months of corrected age).