Early outcome of extremely low birth weight infants in Taiwan

Abstract

We retrospectively evaluated the outcome and the risk factors for mortality among extremely low birth weight (ELBW) infants born at National Taiwan University Hospital. The records of all live-born infants with body birth weight of less than 1,000 g from January 1, 1993, to December 31, 1996, were evaluated. Infants with major anomalies or whose parents refused resuscitation were excluded from the analysis. There were 81 ELBW infants (0.59%) among a total of 13,835 live births during the study period, and 73 cases were enrolled for study. The mean gestational age (GA) was 27.2 (range, 24-34) weeks. Sixty-six percent of the ELBW infants were born by cesarean delivery. Respiratory distress syndrome occurred in 64% of infants and exogenous surfactant therapy was given to 47%, while intermittent mandatory ventilation was given to 85%. Symptomatic patent ductus arteriosus occurred in 34% of infants, septicemia in 30%, chronic lung disease in 48%, grade III to IV intraventricular hemorrhage in 27%, stage III to V retinopathy of prematurity in 33%, and necrotizing enterocolitis in 8%. Neonatal survival was 74%, survival to discharge was 60%, and intact survival was 50%. The survival rate was 40% for infants with a birth body of weight less than or equal to 750 g, and 68% for those with a birth body weight of greater than 750 g. While survival was 27% for infants with a GA of less than 26 weeks, it was 75% for those with a GA of greater than or equal to 26 weeks. The survival rate improved year by year for those with a GA less than 28 weeks. Cox regression analysis of survival showed that Apgar score at 1 minute (p = 0.0063), pulmonary hypertension (p = 0.012), and severe intraventricular hemorrhage (p = 0.0031) were the most important factors associated with mortality. Though the outcome of ELBW infants in our institute seems poorer than in some more developed countries, it is improving. The prognosis for ELBW infants of 24 to 25 weeks' GA remains guarded under our present care.A review of the records of all live-born neonates with a birth weight below 1000 g born in 1993-96 at National Taiwan University Hospital was conducted, with emphasis on outcomes and risk factors for mortality. There were 81 extremely-low-birth-weight infants (0.59%) among the 13,835 live births recorded during the 3-year study period and, after exclusion of infants with major anomalies, 73 cases were enrolled for study. The mean gestational age was 27.2 weeks (range, 24-34 weeks). The most common complications of pregnancy leading to premature delivery were antepartum hemorrhage (44%) and pregnancy-induced hypertension. Respiratory distress syndrome occurred in 64%; exogenous surfactant therapy was provided to 47% and 85% received intermittent mandatory ventilation. Symptomatic patent ductus arteriosus occurred in 34% of infants, septicemia in 30%, chronic lung disease in 48%, grade III-IV intraventricular hemorrhage in 27%, stage III-V retinopathy of prematurity in 33%, and necrotizing enterocolitis in 8%. 54 infants (74%) survived the neonatal period and 44 (60.3%) survived until discharge. The survival rate was 40% for infants with a birth weight of 501-750 g and 68% for those weighing 751-999 g. Survival was 27% for infants with a gestational age under 26 weeks compared with 75% for those with a gestational age of 26 weeks and above. Cox regression analysis of survival indicated that Apgar scores at 1 minute, pulmonary hypertension, and severe intraventricular hemorrhage were the most significant contributing factors to mortality.