title: Short-term outcome of mechanically ventilated infants weighing more than 2499 g at birth: a population based study.
abstract: Very little data exist describing the neonatal outcome of infants of birthweight 2500 g or more who require mechanical ventilation. Our aim was to collect population-based data on such infants in New South Wales (NSW), and to monitor their neonatal morbidity, mortality to 1 year of age and the associated risk factors. The study group (NICUS infants) comprised all 341 infants weighing > 2499 g who were admitted to the seven neonatal intensive care units in New South Wales and mechanically ventilated for 4 h or more between 1 January and 31 December, 1987. Two groups of infants emerged: those who were preterm and mostly had hyaline membrane disease, and term and post-term infants for whom the most common problem was 'perinatal asphyxia'. The most important factors associated with dying were a birthweight of over 3499 g (OR = 2.6; CI 1.03-6.6) and a 1 min Apgar score < 4 (OR = 4.8; CI 1.4-16.9). Study group mothers were significantly more likely than all NSW mothers to have had a spontaneous abortion in the previous pregnancy (P < 0.01), a pre-existing medical condition or an obstetric complication in this pregnancy, or a Caesarean section for this delivery (P < 0.001). This is the first population-based study of high-risk neonates without congenital anomalies to clearly document the worsening prognosis associated with a birthweight over 3499 g. Further research should be directed towards identifying prenatal and perinatal factors which might minimize the morbidity and mortality in this group of babies.
authors.affiliation: Prince of Wales Children's Hospital, Randwick, New South Wales, Australia.
authors.forename: L
authors.initials: L
authors.lastname: Sutton
authors.forename: B
authors.initials: B
authors.lastname: Bajuk
authors.forename: B
authors.initials: B
authors.lastname: Duffy
authors.forename: I
authors.initials: I
authors.lastname: Alexander
authors.forename: J
authors.initials: J
authors.lastname: Arnold
authors.forename: G
authors.initials: G
authors.lastname: Leslie
authors.forename: D
authors.initials: D
authors.lastname: Henderson-Smart
authors.forename: E
authors.initials: E
authors.lastname: John
authors.forename: V
authors.initials: V
authors.lastname: Roberts
authors.forename: A
authors.initials: A
authors.lastname: Berry
mesh_terms: D001034:Apgar Score; D001238:Asphyxia Neonatorum / Q000453:epidemiology / Q000401:mortality / Q000628:therapy; D001724:Birth Weight; D005320:Fetal Macrosomia / Q000401:mortality; D006801:Humans; D006819:Hyaline Membrane Disease / Q000401:mortality / Q000628:therapy; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000401:mortality* / Q000628:therapy; D007234:Infant, Premature; D016015:Logistic Models; D009017:Morbidity; D011446:Prospective Studies; D012121:Respiration, Artificial; D012307:Risk Factors; D012640:Seizures / Q000453:epidemiology