Survival of Premature and Low Birth Weight Infants: A Multicenter, Prospective, Cohort Study in Iran

Document Type: Original Article


1 Pediatric Health Research Center, Tabriz University of Medical Sciences, Tabriz, Iran

2 Department of Pediatrics, Tabriz University of Medical Sciences, Tabriz, Iran

3 Tabriz Health Services Management Centre, Tabriz, Iran

4 Mashhad Omolbanin Hospital, Mashhad, Iran

5 Faculty of Nursing and Midwifery, Tabriz University of Medical Sciences, Tabriz, Iran


Background: The survival rate of preterm and low-birth-weight (LBW) infants depends on various factors such as birth weight, gestational age, and quality of care. The present study aimed at evaluating the survival rate of preterm and LBW infants, predictive factors, and the risk of mortality in three training hospitals of Mashhad and Tabriz cities.
Methods: This prospective, cohort study was conducted during six months from 2013 to 2014. Infants with birth weight ≤1500 g or gestational age ≤32 weeks were enrolled. Their information was gathered by using data collection forms and clinical risk index for infants (CRIB II) was calculated for each participant. Infants were followed up until discharge from the hospital and their outcomes were determined. Kaplan-Meier and Log rock tests were used for survival analysis. Cox regression was also applied in order to find out the factors associated with infants’ survival.
Results: Among the 338 followed up infants, 97 (28.7%) died and 241 (71.3%) remained alive. The median of preterm and LBW infants’ overall survival rate was 76 days (CI: 60.4-91.5). Multivariate Cox regression analysis indicated that three factors of birth weight, base excess, and fifth minute Apgar score had a significant relationship with the survival rate of infants (P<0.05).
Conclusion: The survival rate of preterm and low-weight infants was acceptable in this study (71%). Birth weight, fifth minute Apgar score, and base excess were important items that affected infants’ survival and could be considered in predicting it in neonatal intensive care units.


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