Sex-Related Nutritional Outcomes Among Preterm Very Low Birth-Weight Infants

Background: Sex-specific differences exist in morbidity and growth yet little is known about other nutritional outcomes in preterm very low birth-weight (VLBW) infants. This is important because providing optimal nutrition is essential to promote growth and reduce neurodevelopmental impairment.

Purpose: To determine the effect of sex on days to full enteral feedings and other nutritional outcomes.

Methods: This was a longitudinal 2-group cohort study using secondary analysis of existing data of 313 infants born ≤32 weeks gestation and weighing ≤1500 g. Information regarding nutritional outcomes was obtained from the infant's electronic medical records.

Results: While not statistically significant, male infants reached full feeds nearly 3 days later (18.1 vs 15.2; P = .89), required parenteral nutrition for nearly an additional 4 days (18.3 vs 14.1; P = .37), and had a central line for 3 days longer (19.6 vs 15.7; P = .65) than female infants. Males had higher direct bilirubin levels (P = .02), more emesis (P = .003), and more late-onset sepsis (P = .03). Birth weight for males was higher at birth but not at 6 weeks and while the slope of weight increase over the 6 weeks was higher in males (P = .04), growth velocity was similar between sexes yet tended to be higher in females.

Implications For Practice And Research: Nurses are essential in ensuring preterm infants in the neonatal intensive care unit receive optimal nutrition. This study supports nurses should consider sex-specific differences in nutritional outcomes among VLBW infants in precision based nutritional support.