Nitrogen balance of very preterm infants with extrauterine growth restriction

摘要

The aim of this study was to investigate the changes of nitrogen balancein preterm infants with extrauterine growth restriction (EUGR) duringhospitalization. A total of 64 very preterm infants admitted to the NeonatalMedical Center of Huai’an Maternity and Child Healthcare Hospital wereenrolled from May to October 2014. These infants had gestational ages lessthan 32 weeks and were within 24 hours after birth. The enrolled infants wereclassified into EUGR (n=18) and non EUGR (n=46) groups according to thedischarge weight being below or above the 10th percentile of the expectedintrauterine growth for the postmenstrual age. The urinary urea nitrogenof the infants were assayed by the Kjeldahl method and determined at 1st,7th, 14th and 28th day after birth. Nitrogen balance at each time point wascalculated and compared between the EUGR and non EUGR groups. Theincidence rate of small for gestational age (SGA) infants (33.3% vs 0.0%) inthe EUGR group was higher than that in non EUGR group. The difference wasstatistically significant (p 0.05). The birth weight (1.37±0.20 vs 1.63±0.27)and birth weight Z-score (-1.14±0.29 vs-0.37±0.66) in the EUGR group werelower those in non EUGR group. The difference was statistically significant(all p 0.05). At the 1st, 7th, 14th and 28th day after birth, nitrogen balancevalues of all infants were negative, showing an upward trend with age. At eachobservation time point, the nitrogen balance values in the EUGR group werelower than those in non-EUGR group. The differences on the 1st and 28thday between two groups were statistically significant (both p0.05).All very preterm infants of study were in negative nitrogen balance while theinfants of EUGR group had more seriously negative balance.