Nitrogen balance of very preterm infants with extrauterine growth restriction

Relationship between nutrient intakes in the transition phase and postnatal growth of preterm infants: a systematic review

Nutrition practices for preterm infants include phases of parenteral nutrition, gradually interrupted parenteral nutrition (transition phase), and full enteral nutrition. However, nutrition management during the transition phase is frequently overlooked. This review examined the relationship between nutrient intake during the transition phase and preterm infant growth. PubMed, Embase, Web of Science, Cochrane, Chinese National Knowledge Infrastructure Database, Wanfang Database, and Chinese Science and Technique Journals Database were searched for studies examining the relationship between nutrient intake during the transition phase and postnatal growth of preterm infants from each database's earliest inception through February 28, 2022. The quality of the studies was assessed using the Newcastle-Ottawa scale. A total of three studies conducted in the USA, Italy and China met the inclusion criteria. The growth indicators were extrauterine growth restriction (weight < 10th percentile for post-menstrual age) or inadequate weight growth velocity (growth velocity < 15 g/kg/d) at discharge or the end of the transition phase. The transition phase was divided into two periods in two studies: the early period (parenteral energy intake > 50% of total energy intake) and the late period (enteral energy intake > 50% of the total energy intake). The cumulative protein intake in the transition phase was generally lower in preterm infants with extrauterine growth restriction or inadequate weight growth velocity, especially in the early transition phase. The deficiency of energy and protein intake during the transition phase cannot be explicitly determined due to differences in growth indicators and definitions of the transition phase. However, enteral protein intake should be closely monitored in the early transition phase to ensure a better growth rate for preterm infants. To elucidate potential associations, further well-designed research will be required.

Evaluation of nutrition status of very preterm infants in neonatal intensive care units using different growth indicators

BACKGROUND

 Nutrition status of very preterm infants in the neonatal intensive care unit (NICU) is strongly associated with postnatal growth. This study aimed to develop indicators of nutrition status using growth data of very preterm infants during hospitalization.

METHODS

The data of 596 newborns from eight NICUs were retrospectively analyzed. Inclusion criteria were birth at <32 weeks' gestation, NICU admission ≤24 h after delivery, and length of hospital stay ≥28 days. Three indicators were evaluated: (indicator I) prevalence of extrauterine growth restriction (EUGR); (indicator II) z-score for change in weight from birth to discharge, adjusted for birth weight z-score and gestational age; and (indicator III) change in weight z-score from birth to discharge, adjusted for birth weight z-score, gestational age, and time to regain birth weight. Using data from NICU 1 as the reference for the latter two indicators, we established linear regression models of the adjusted change in weight z-score from birth to discharge. The difference between the observed value and the baseline value (calculated by the two models) served as the nutrition indices.

RESULTS

The prevalence of EUGR differed significantly between the eight NICUs (P = .009). Statistically significant differences were found between the mean indices calculated by the other two models (all P < .05).

CONCLUSIONS

Indicator III, change in weight z-score from birth to discharge (adjusted for birth weight z-score, gestational age, and time to regain birth weight), appears to be the most accurate for evaluating the quality of nutrition in the NICU.