Interneonatal intensive care unit variation in growth rates and feeding practices in healthy moderately premature infants

Abstract

Background: Variation in care and outcomes of very low birth weight infants (VLBW) in neonatal intensive care units (NICU) has been widely reported in the past decade. Less is known about care provided to healthy premature infants born between 30 and 35 weeks gestational age (GA). We have previously reported inter-NICU variation in discharge (D/C) timing and achievement of maturational milestones in this population.

Objective: To compare inter-NICU growth outcomes and feeding practices in healthy, moderately premature infants.

Methods: Records of 450 infants, 30 to 35 weeks gestation, without medical or surgical complications, and consecutively discharged from 15 Massachusetts NICUs (nine Level II and six Level III) were reviewed. Final analyses included 382 infants with hospital length of stay >6 days (d).

Results: GA at birth and birth weight (BW) were 33.2 weeks (SD 1.2) and 2024 g (389). Mean Z-score decreased 0.67z (0.37) from birth to D/C. Weight loss from birth to 7 d averaged 4.0%. Mean growth velocity from 7 d to D/C was 13.3 g/k/d (5.2) with net growth velocity of 5.5 g/k/d (5.6). Mean net growth velocity ranged from 0.1 to 8.4 g/k/d (p<0.001) among study NICUs. Time of initiation, rate of advancement and caloric density of feedings also varied significantly between NICUs.

Conclusion: Mean NICU growth velocity of healthy, moderately premature infants did not achieve in utero growth standards. There was significant inter-NICU variation in growth outcomes and feeding practices. Further study is needed to identify practices associated with better growth in this healthy moderately premature infant population.