[Perinatal differences in relation to the severity of perinatal asphyxia]

Despite the widespread use of the term perinatal asphyxia, there is little uniformity in the clinical definition of asphyxia, which makes comparison of incidence, treatment and outcome very difficult. The aim of this study was to know the perinatal differences of perinatal asphyxia in relation to its severity (severe and non-severe).

A prospective epidemiological study of perinatal asphyxia in fullterm infants born in our hospital between November 1991 and February 1995 was carried out. Perinatal asphyxia was graded as non-severe (1 minute Apgar score < or = 6 and/or umbilical artery pH < 7.20, with abnormal fetal heart rate patterns and/or meconium-stained amniotic fluid and the need for immediate neonatal resuscitation) and severe (1 minute Apgar score < or = 3 and umbilical artery pH < 7.10). The perinatal variables were graded as prenatal (gestational and obstetric), neonatal (resuscitation, general data of the newborn and organic manifestations of asphyxia) and postneonatal (neurologic sequelae at follow-up).

During the study period there were 3.343 fullterm live births. Perinatal asphyxia developed in 156 cases (31 severe and 125 non-severe), with an incidence of 4.66 cases per 100 fullterm newborns. Neurologic manifestations (hypoxic-ischemic encephalopathy) during the neonatal period were present in 25.6% and extraneurological manifestations (hypoxic-ischemic disease) in 41.7% of the cases. The incidence of neurologic sequelae, in 115 asphyxiated full-term infants followed for at least 12 months, was 16.5% (19 cases). The main differences between severe and non-severe perinatal asphyxia were: chronic maternal diseases, distocic deliveries, thick meconium-stained amniotic fluid, all of the variables of neonatal resuscitation (Apgar score, umbilical artery pH, etc.), neurological and extraneurological (mainly pulmonary, digestive and cardiologic) manifestations during the neonatal period and neurological sequelae at follow-up.

The main perinatal differences in relation to the severity of perinatal asphyxia were important in clinical management of asphyxiated newborns (neonatal resuscitation and systemic manifestations) and in their follow-up (early detection of neurologic sequelae).