Comparative analysis of initial vocalizations of preterm and full-term infants with and without risk for development.

Purpose: To compare the evolution of vocalization in preterm and full-term infants, with and without risk for development, analyzing the possible association of sociodemographic, obstetric and psychosocial variables with vocalization.

Methods: The study sample consisted of 30 infants, aged 3 months and 1 day to 4 months and 29 days (Phase 1) and 6 months and 1 day to 7 months and 29 days (Phase 2), of both genders, with gestational age <37 weeks (preterm group) and >37 weeks (full-term group). The following instruments were used for data collection: Child Development Risk Indicators (IRDl), the Denver II Test, an interview on the experience of motherhood with sociodemographic, obstetric and psychosocial data, as well as filming of the mother-infant dyad at the two phases of the research. Footage was analyzed using the EUDICO Linguistic Annotator (ELAN) software and the results were statistically analyzed on the STATISTICA 9.0 software.

Results: The larger the total number of Phase II infants' and mothers' vocalizations using motherese, the greater the number of IRDls present. Significant increase in vocalizations without motherese was also observed in Phase 2. Sociodemographic variables, gestational age, weight at birth, maternal schooling, and the Brazil Criterion did not directly affect the infants' vocalization level.

Conclusion: Analysis of the infants' vocalizations was sensitive to risk development and Child Development Risk Indicators in Phase 1; the Denver-language test was more effective in Phase 2. No influence of the sociodemographic variables was observed in the phases studied.