Abnormal developmental patterns of suck and swallow rhythms during feeding in preterm infants with bronchopulmonary dysplasia

Infants with bronchopulmonary dysplasia (BPD) often have difficulty achieving coordinated suckle feeding. To analyze rhythmic differences during feeding in infants with BPD we performed weekly studies of 14 infants with BPD (eight male, six female; postmenstrual age [PMA] 32.1 to 39.7 weeks); and a PMA-matched control group without BPD (n=20), from initiation of bottle feeding until discharge, with simultaneous digital recordings of pharyngeal and nipple (teat) pressure. Unlike the control group, there was no significant correlation between PMA and stability of suckle rhythm, aggregation of suckles or swallows into runs, or length of suckle runs. Comparing those infants >35 weeks' PMA, the group with BPD had significantly decreased stability of suckle rhythm (increased coefficient of variation of suckle-suckle intervals: 0.34, SE 0.02 vs 0.254, SE 0.014; p=0.003), decreased aggregation into suckle runs (71.1, SE 3.4% vs 85.4, SE 2%;p=0.001), and decreased length of suckle runs (7.2, SE 0.9 vs 13.1, SE 1.9 suckles/run; p=0.003). Percentage of swallows in runs was also decreased in the cohort with BPD (58, SE 3.8% vs 77.2, SE 3.5%; p<0.001), as was length of swallow run (5.3, SE 0.5 vs 10.7, SE 1.1;p<0.001). Thus, in infants with BPD, anticipated maturational patterns of suckle and swallow rhythms did not occur. Delay in attainment of stable suckle and swallow rhythms in preterm infants, especially after 35 weeks' PMA, may predict subsequent feeding and neurological problems.