The immaturity of born to preterm infants may predispose to sucking difficulties. This research aimed to evaluate if pacifier use is associated with preterm birth and influenced in type of infant feeding. This comparative cross-sectional study was conducted in Belo Horizonte, Brazil and evaluated 250 children aged 3 to 5 years. As a sample, two groups were established: the normal term children group (n=125) was selected at a day-care centre and the group of preterm children (125) was identified at a public university hospital with a preterm care project from birth to seven years of age. To collect data, a pre-tested questionnaire regarding information on gestational age, infant development, infant feeding and non-nutritive sucking habits was used for both groups. Bivariate and multivariate Poisson regression was used for the statistical analysis. Pacifier use was more prevalent in the preterm group (PR=1.20, 95% CI=1.02-1.42) who used the bottle (PR=1.38, 95% CI=1.15-1.64) and were breastfed for less than six months (PR=1.19, 95% CI=1.01-1.41). The majority of breastfed infants were of normal term birth (PR=1.14, 95% CI=1.04-1.20) and had monthly family income greater than USD 450.28 (RP= 1.10, 95% CI=1.01-1.20). In this study, pacifier use was more prevalent among preterm infants and associated with less than six months of breastfeeding and used of bottle. Monthly family income was associated with a prevalence of breastfeeding.

Objective: To analyze the difference of socioeconomic factors among mothers of preterm and full-term infants. Material and Methods: A cross-sectional retrospective study was developed with 250 mothers of children aged three to five years. The sample was divided into two groups: 125 mothers of preterm infants from the referral center of a public hospital in the city of Belo Horizonte, Brazil and 125 mothers of children born full-term at a daycare center within the same city. A pre-tested questionnaire was used to collect socioeconomic data and type of breastfeeding. To verify if there was association between the dependent variable gestational age at birth and the independent variables, the chi-square test was used. A final model with multiple Poisson regression estimated prevalence ratio values for each independent variable was developed. Results: The final multiple regression model showed that mothers that have a low monthly income of up to USD 450.28 (PR = 1.979, 95% CI = 1.082-3.620), used drugs, cigarettes, or alcohol during their pregnancy (PR = 4.095, 95% CI = 2.422-6.921), and did not breastfeed (PR = 2.294, 95% CI = 1.205-4.369) were more likely to give birth to preterm infants. Conclusion: Low monthly family income, use of drugs, alcohol, or smoking during pregnancy and absence of breastfeeding were more frequent on mothers of preterm infants.