[Sucking in preterm newborns and the sucking stimulation]

Non-nutritive sucking stimulation may anticipate the beginning of oral feeding and may influence the development of sucking in pre-term newborns.

To describe the development of the sucking pattern and the effects of NNS.

Participants of this study were 95 preterm newborns (PTNB), adequate for their gestational age (GA), born with GAs inferior or equal to 33 weeks, randomly distributed in three groups: Group 1 (G 1)--control group--did not undergo NNS stimulation; Group 2 (G2) underwent NNS stimulation with orthodontic pacifier for premature infants; Group 3 (G3), underwent NNS stimulation with a gloved finger. All three groups of newborns underwent weekly NNS evaluations with a gloved finger and, after the beginning of the oral feeding (OF) they underwent NNS and nutritive sucking (NS) evaluations using a baby's mini milk bottle.

In all three groups, except for the stress signs in NNS and coordination between sucking- swallowing-breathing in NS, as the corrected gestational age (GA at birth plus postnatal age) increased, the occurrence probability of all studied sucking characteristics (NNS and NS) rose. In the NNS: sucking began easily (SBE) with no differences between the groups regarding rhythm, strength and coordination between lips, tongue and jaw; there was a higher probability of labial sealing, of tongue central groove formation and of tongue peristaltic movements in G3; stress signs were higher in G2 (> 37 weeks). In the NS: SBE, coordination between lips, tongue and jaw, volume of ingested milk per total time did not show differences between the groups; rhythm and coordination between sucking, swallowing and breathing were higher in G3, labial sealing was higher in G1and G3 (< 34 weeks), and stress signs higher in G2 (> 33 weeks).

The sucking pattern of PTNB developed due to the corrected gestational age, observing that NNS stimulation increased the occurrence probability of labial sealing, rhythm, tongue central groove formation, tongue peristaltic movements and coordination between sucking, swallowing and breathing. The gloved finger was the most effective instrument for NNS stimulation.