The development of sucking patterns in preterm, small-for-gestational age infants

OBJECTIVE: To determine whether the development of sucking patterns in small-for-gestational age (SGA) preterm infants differs from appropriate-for-gestational age (AGA) preterm infants.

STUDY DESIGN: We assessed sucking patterns in 15 SGA and 34 AGA preterms (gestational age<or=36 weeks) longitudinally from 34 to 50 weeks postmenstrual age (PMA) using the Neonatal Oral-Motor Assessment Scale (NOMAS). At each measurement, we scored sucking as normal, dysfunctional, or disorganized. We examined the development of their sucking patterns in relation to clinical characteristics.

RESULTS: SGA preterms developed a normal sucking pattern later than did AGA preterms (median, 50 versus 44 weeks PMA, P=.002). At term-equivalent age, none of the SGA and 38% of the AGA preterms showed normal sucking (P<.05); at 48 to 50 weeks PMA this was 54% and 81%, respectively (P=.064). Abnormal sucking including "incoordination" and dysfunctional sucking were more prevalent in SGA preterms than in AGA preterms (median, 11% versus 0% per infant, P<.05). A higher gestational age and z-score for birth weight were predictive of normal sucking at 50 weeks PMA.

CONCLUSIONS: SGA preterms developed a normal sucking pattern later than AGA preterms. Many AGA preterms also developed a normal mature sucking pattern only after they had reached term age.