Neurodevelopmental Outcomes And Associated Risk Factors Of Very Low Birth Weight And Extremely Low Birth Weight Infants

Advances in perinatal medicine and neonatal medicine have resulted in increased survival rates for very low birth weight infants （VLBWI） and extremely low birth weight infants （ELBWI）. However, improvements in survival have not been accompanied by proportional reductions in the incidence of neonatal morbidity and neurodevelopmental impairment in this population. Although growing concern has been given to the neurodevelopmental outcomes of VLBWI and ELBWI, there are few studies in China.Objective:To analyse the short-term outcomes and neurodevelopmental outcomes of VLBWI and ELBWI; To investigate the neurodevelopmental outcomes associated factors of VLBWI and ELBWI; We sought to determine changes of neurodevelopmental outcomes that have occurred over the recent years. Finally, to provide clinical practice guidance for perinatology and neonatology, by which to improve the neurodevelopmental outcomes.Methods:Part one:The hospitalized VLBWI and ELBWI from January1^st2009to December31^st2010were included in our study. Clinical data were collected, such as general information, perinatal conditions, neonatal morbidity and treatment measures. Mortality and morbidity during initial hospitalization were assessed.Part two:The hospitalized infants from2009to2010who had finished the infant development test of BSID-Ⅱ for neurological development at corrected gestational aged18months to30months were prospectively reviewed. There were89infants included to analyze the neurodevelopmental outcomes and risk factors. Based on the definition of neurodevelopmental impairment （NDI） reported by National Institute of Child Health and Human Development （NICHD） Neonatal Net-work,89infants were divided into neurodevelopmental normal or abnormal group. Potential high risk factors were analyzed with logistic stepwise regression.Part three:The population included143VLBWI and ELBWI admitted from October1^st2005to December31^st2010who had finished the infant development test of BSID-Ⅱ. The neurodevelopmental outcomes between two periods （2005to2008（period1）;2009to2010（period2）） were compared.Results:Part one:There were343infants admitted in our hospital from January1^st2009to December31^st2010, of whom,22cases （6.4%） died during hospitalization, and there were92cases （26.8%） with treatment withdrawal, and229cases（66.8%） were discharged. The incidence of major morbidity, such as respiratory distress syndrome, brain injury, necrotizing enterocolitis, retinopathy of prematurity, bronchopulmonary dysplasia, sepsis were52.2%（179cases）、16.3%（56cases）、10.5%（36cases）、19.8%（68cases）、24.2%（83cases）、24.2%（83cases）, respectively.Part two:This study consisted of89infants, with gestationalage of29.7（28～32） weeks and birth weight of1200（1040～1365） grams. Neurodevelopmental impairment occurred in12cases （13.5%）. With regard to the BSID-Ⅱ assessment, MDI （mental developmental index）<70occurred in3cases （3.4%）; PDI （psychomotor developmental index）<70occurred in11cases （12.4%）. Two cases （2.3%） were diagnosed as CP （cerebral palsy）, and12cases （13.5%） were diagnosed as motor retardation. None occurred blind in both eyes or hearing impairment requiring amplification. Logistic stepwise regression showed brain injury was the independent risk factor of neurodevelopmental impairment （P=0.014, OR=5.397）.Part three:The subjects in two-period study were similar in gender, gestational age, and birth weight. The neurodevelopmental outcomes in period two improved:the MDI score was increased （（97.0±14.6） versus （88.6±19.2）, P=0.004）, and the rate of MDI<70was decreased （3.4%versus14.8%, P=0.014）.Conclusions:The incidence of neonatal morbidity and neurodevelopmental impairment of VLBWI and ELBWI remained high. Brain injury was the risk factor of neurodevelopmental impairment. Recent years, the neurodevelopmental outcomes seem to improve, and the reasons leading to this change need further study. Both doctors and parents should pay attention to the follow-up and early intervention of VLBWI and ELBWI after discharge, by which to improve their neurodevelopmental outcomes.