Long-term outcomes of extremely preterm infants and extremely low birth weight infants with low one-minute Apgar score

Abstract

Objective To investigate the relationships between low one-minute Apgar score and the prognosis of extremely preterm infants (EPI) and extremely low birth weight infants (ELBWI). Methods Altogether 50 EPI and ELBWI who had a low one-minute Apgar score (≤7) and were admitted to the Neonatal Intensive Care Unit (NICU) of Peking University Third Hospital from January 1,2010 to December 31, 2015 were enrolled in this study. All of them were divided into two groups according to their Apgar score: mild group (4-7) and severe group (0-3). Medical records of the subjects were reviewed and an at least 18 months follow up study was conducted. Conditions of all subjects during perinatal period and hospitalization were summarized. Outcomes and follow-up results were compared between the two groups by using Fisher exact test. Results (1) General information: Fifty infants were involved, among which 37 had a mild low Apgar score and 13 had a severe low Apgar score. The mean gestational age was (27.7±2.1) weeks and the mean birth weight was (884.4±174.3) grams. (2) Main complications (some infants with more than one complication): There were 42 cases of neonatal respiratory distress syndrome, 12 cases of pulmonary hemorrhage, 21 cases of bronchopulmonary dysplasia, 31 cases of patent ductus arteriosus, 36 cases of intraventricular hemorrhage, 22 cases of white matter damage and six cases of retinopathy of prematurity. (3) Outcomes: The survival rate was 48% (24/50) and the mortality rate was 52% (26/50). Among the 26 infants, five died despite treatment and 21 died within 72 hours after their parents giving up treatment. There were no significant differences in the survival rates, mortality rates and rates of abandon treatment between the two groups [43% (16/37) vs 8/13; 11% (4/37) vs 1/13; 46% (17/37) vs 4/13; Fisher exact test, all P>0.05]. (4) Follow-up results: Twenty-one infants were followed-up to at least 18 months of age, among which four were normal, 10 had growth retardation and recurrent respiratory tract infection and seven had motor development retardation. The incidence of motor development retardation in severe group was higher than that in mild group, and the difference between them was statistically significant (5/8 vs 2/13, Fisher exact test, P=0.046). Conclusions EPI or ELBWI with a low one-minute Apgar score have many nosocomial complications, resulting in high mortality and high incidence of motor development retardation. Key words: Infant, extremely low birth weight; Apgar score; Survival rate; Treatment outcome