Related Experiment Video
Updated: Aug 18, 2026
Development of a Neonatal Piglet Acute Lung Injury Model Recreating the Early Environment of Preterm Infant Lungs
Published on: October 31, 2025
Interneonatal intensive care unit variation in growth rates and feeding practices in healthy moderately premature
Mary T Blackwell1, Eric C Eichenwald, Karen McAlmon
1Department of Pediatrics. Lowell General Hospital, Lowell, MA, USA.
Insights
Growth outcomes for moderately premature infants varied significantly between neonatal intensive care units (NICUs). Practices in NICUs did not consistently support optimal growth for these healthy infants.
Area of Science:
- Neonatalogy
- Pediatric Growth Studies
- Infant Nutrition
Background:
- Significant variation in care and outcomes for very low birth weight infants (VLBW) in neonatal intensive care units (NICUs) is documented.
- Limited data exists on the care and growth of healthy premature infants between 30 and 35 weeks gestational age (GA).
- Previous research highlighted inter-NICU differences in discharge timing and milestone achievement for this population.
Purpose of the Study:
- To compare inter-NICU growth outcomes in healthy, moderately premature infants.
- To analyze feeding practices among neonatal intensive care units (NICUs) for this specific infant group.
Main Methods:
- Retrospective review of 450 infants (30-35 weeks GA) without complications from 15 Massachusetts NICUs.
- Final analysis included 382 infants with a hospital length of stay greater than 6 days.
- Data collected on growth parameters and feeding practices.
Main Results:
- Mean Z-score decreased by 0.67 from birth to discharge.
- Average weight loss within the first 7 days was 4.0%.
- Significant inter-NICU variation observed in net growth velocity (0.1 to 8.4 g/k/d) and feeding practices (initiation, advancement, caloric density).
Conclusions:
- Neonatal intensive care unit (NICU) growth velocity for healthy, moderately premature infants did not meet in utero growth standards.
- Substantial inter-NICU variability exists in growth outcomes and feeding strategies.
- Further research is required to identify best practices for promoting growth in this population.
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.
