Effect of zero-separation in mother-newborn care unit on preterm infant's stress and growth

Background and objectives Previous studies have focused on the effect of kangaroo mother care (KMC) on stress among stable infants. Evidence regarding continuous zero-separation care among sick preterm infants remains limited. We hypothesised that keeping sick preterm infants with mothers in mother-newborn care unit (MNCU) with zero-separation would result in less stress and better growth as compared to inmates of conventional neonatal intensive care unit (NICU). Methods This cohort study enrolled preterm infants admitted to either MNCU or NICU. The assignment of infants in both the groups was non-random and based on bed availability. Preterm infants were admitted to MNCU if bed was available. Once all beds were occupied, infants were admitted in NICU. Stress was assessed using salivary cortisol and preterm infant pain profile (PIPP) scores. Growth parameters including body weight, length and head circumference were measured at birth and at discharge. Results 180 preterm (90 from each MNCU and NICU group) infants were enrolled in the study. MNCU infants showed a significant reduction in cortisol levels (-0.2±0.4µg/dL), whereas those in the NICU group showed an increase (+0.43±0.3 µg/dL); indicating significantly lower stress among MNCU group (P<0.001). Mean PIPP scores were significantly lower in the MNCU group as compared to NICU group (6.7±2.5 vs. 12.68 ± 2.03; P<0.001). Growth variables were significantly better in MNCU as compared to NICU, with higher daily weight gain (19.7±11.08 vs. 8.3±6.6 g/day; P<0.001), length gain (0.11±0.08 vs. 0.08±0.09 cm/day; P=0.003), and head circumference gain (0.11±0.10 vs. 0.03±0.05 cm/day; P<0.001). Interpretations and conclusions Zero-separation in MNCU is associated with reduced stress and better growth as compared to those admitted in NICU.