The studies reported on in this thesis addressed the development of suckingpatterns in preterm newborns. Preterm infants often have problems learningto suckle at the breast or to drink from a bottle. It is unclear whether this isdue to their preterm birth or whether it is the consequence of neurologicaldamage. From the literature, as well as from daily practice, we know thatthere is much variation in the time and in the way children start suckingnormally. Factors such as birth weight and gestational age may indeed berisk factors but they do not explain the differences in development. A smallspot-check proved that most hospitals in the Netherlands start infants onoral feeding by 34 weeks’ post-menstrual age (pma). By and large the policyis aimed at getting the infant to rely on oral feeding entirely as soon aspossible. The underlying rationale is to reduce the stay in hospital, and theidea that prolonged tube-feeding delays or even hampers the development ofsucking.
Are sucking skills in a specific period (in weeks post menstrual age, PMA) associated with an abnormal development at age 2?Do preterm infants with abnormal sucking patterns in the early post term period differ in motor skills at age 5 from preterm infants with normal sucking patterns in the same early post term period?
AIM: To determine the association between sucking in infants born preterm and developmental outcomes at 5 years.METHOD: Thirty-four infants were included (mean gestational age 30wks 4d, mean birthweight 1407g). The Neonatal Oral-Motor Assessment Scale was used longitudinally from 37 to 50 weeks postmenstrual age. At 5 years, we assessed motor skills, intelligence, language, verbal memory, and behavioural problems. Linear regression analyses were performed to test whether aspects of sucking behaviour predicted these developmental outcomes. Where linear regression was not appropriate, Spearman's correlation coefficients were calculated between sucking and developmental outcomes.RESULTS: Sucking was associated with total motor skills (B [unstandardized correlation coefficient for normally distributed data]=22.66, 95% confidence interval [CI] 6.61 to 38.71), balance (Spearman's ρ=0.64, p<0.001), total intelligence (B=-1.16, 95% CI -1.89 to -0.44, B=10.48, 95% CI 0.39 to 20.71, B=-2.22, 95% CI -3.42 to -1.02), verbal intelligence (B=-0.95; 95% CI -1.83 to -0.07, B=-2.02; 95% CI -3.55 to -0.49), performance intelligence (B=-1.34, 95% CI -2.13 to -0.54, B=12.36, 95% CI 1.13 to 23.60, B=-2.37, 95% CI -3.75 to -0.96), and language (B=-1.78, 95% CI -3.36 to -0.19). All associations were in the same direction: the better the sucking, the higher the test scores. Verbal memory and behavioural problems were not associated with sucking.INTERPRETATION: Abnormal sucking between 42 weeks and 50 weeks postmenstrual age may reflect abnormal neurological functioning in children born preterm.
