This study retrospectively reviewed the data of 475 VLBW premature infants admitted over a period of 8 years. Consistent with other researches[1
], our study noted a trend toward increasing admission rate of VLBW infants. Relative researches have reported a wide range of mortality rates (from 57% to less than 10%) of VLBW neonates[4
]. In-hospital mortality of our unit in 2006-2009 was approximately equal to that from Banaras Hindu university hospital in India (28.1% vs 22.2%)[2
]. Survival of VLBW premature infants was not significantly increased in 2006-2009 than in 2002-2005, however, progress was achieved in perinatal care of infants born very premature. It is noteworthy that a higher percentage of infants with GA < 28 weeks were delivered by cesarean section in 2006-2009, demonstrating the better chance of survival that these infants now have[11
]. Quite a proportion of treatment was given up due to economical embarrassment, and withdrawal occurred more frequently in 2006-2009. This might be explained by the fact that the degree of increase in health expenditure was more than that in the average personal income from 2004 to 2008, regionally (102.9% vs 42.1%)[15
]. It was estimated that the cost for NICU hospitalization of VLBW infants is very high for the current level of economy, either in developed regions or developing regions[17
According to European consensus guidelines on the management of neonatal respiratory distress syndrome in preterm infants - 2010 Update[9
], clinicians should offer a single course of antenatal steroids to all women at risk of preterm delivery from about 23 weeks up to 35 completed weeks’ gestation. Guideline for the use of antenatal corticosteroids for fetal maturation suggested that babies with or at high risk of RDS should be given bovine or porcine surfactant with the recommended dose of 200mg/kg[8
]. The low frequency and inadequate dose of antenatal corticosteroids as well as postnatal PS administration indicates several deficits in our perinatal care and may partly explain the increasing incidence of RDS. Inconsistent with researches demonstrating that antenatal corticosteroids could decrease the risk of intraventricular hemorrhage (IVH)[11
], our study showed that 43.3% of infants treated with antenatal corticosteroids developed IVH as opposed to 32.1% of those untreated. This might be associated with the insufficient administration of antenatal corticosteroid.
Pulmonary hemorrhage, PPHN, BW<1000 grams and GA<33 weeks were risk factors of in-hospital mortality. Apart from these, illness severity was also demonstrated in other researches to associate with outcome of neonates. Clinical risk index for babies (CRIB), Score for neonatal acute physiology II (SNAP II) and Score for neonatal acute physiology-periantal extension (SNAP-PE II) were most commonly used illness severity score models[22
]. Calculation of these scores requires items such as FiO2
, blood pressure and arterial blood gas analysis within first 24 hours of life. On account of data missing or the lack of available monitoring facilities in 2002-2005, our study was not powered to estimate individual illness severity scores. Respiratory diseases were shown to be most responsible for mortality, therefore, generation of awareness among expectant mothers to seek prenatal care and effective respiratory management (e.g. early and adequate administration of antenatal corticosteroid and postnatal PS) are important to improve our perinatal care. Enteral feeding and feeding before 3 postnatal days were found to be protective factors of in-hospital mortality. Early enteral feeding has been recommended by various guidelines and minimal enteral nutrition (MEN) was reported to improve gastrointestinal capacity, decrease side effects due to parenteral nutrition and reduce the risk of NEC[25
]. Early feeding improves neonatal outcome through preventing catabolic disturbance and contributes to normal physiological development, however, controversies remain concerning the administration of MEN[28
]. Progression rate and milk components are areas of active research.
We developed a prediction score model based on logistic regression analysis. Compared with other scoring models, we explored more perinatal factors such as feeding strategy while others were chiefly focused on physiologic status of neonates. Although the score model has good calibration and discrimination, its application in clinical practice might be prevented by the negative cutoff point.
The limitations of our study included the retrospective single center design and analysis of outcomes till discharge. Unfortunately, the ideal prospective multicenter study is very difficult to carry out in developing regions due to limited resources in money and manpower, and there is no reliable system to do post-discharge follow up currently. To get a more clearly defined clinical picture, multi-center studies of planned follow-up will be needed.