Evolução do ritmo de sucção e influência da estimulação em prematuros*** Development of sucking rhythm and the influence of stimulation in premature infants

Background: the sucking development pattern of the preterm newborn (PTNB) in the neonatal period is important for an effective sucking and oral motor development. The establishment of a safe and efficient feeding in pre-term newborns is related to a rhythmic and coordinated sucking. Nonnutritive sucking stimulation can have an influence on the development of sucking and the development of sucking rhythm of pre-term newborns. Aim: to analyze the development of the sucking rhythm, in non-nutritive and nutritive sucking in preterm newborns, as a consequence of non-nutritive sucking stimulation and in terms of corrected gestational age. Method: 95 preterm newborns randomly divided in three groups: Group 1, control group (35 PTNB), did not receive non-nutritive sucking stimulation; Group 2 (30 PTNB), received non-nutritive sucking stimulation using an orthodontic pacifier for premature infants (Nuk®); and Group 3 (30 PTNB), received non-nutritive sucking stimulation using a gloved finger. Results: the mean gestational age was of 30.5 weeks (± 1.57), the mean corrected gestational age at the moment of enrollment in the study was of 31.6 weeks (± 1.31), and the mean birth weight was of 1.390 grams, with no statistical differences between the groups. The number of sucking bursts and pauses per minute increased by 0.16 per week and the duration of the bursts by 0.81 seconds; the duration of pauses decreased by 3.8 seconds per week while the number of sucks/second was constant, 1.15 and 0.95 for non-nutritive and nutritive sucking, respectively. No statistically significant differences were found between the groups for any of the studied variables. Conclusion: the stimulation of non-nutritive suction in preterm newborns did not modify the post-natal development of sucking rhythm. The process of maturation, represented by the corrected gestational age, was considered the most responsible factor for this process.