Perinatal asphyxia: multivariate analysis of risk factors

Perinatal asphyxia contributes greatly to neonatal mortality and morbidity. In developing countries, the need for risk assessment in perinatal asphyxia is obvious because of the high birth rate and limited perinatal resources.

To determine the incidence and risk factors of perinatal asphyxia in infants who were delivered from mothers with high-risk conditions.

A prospective study over a 5-year period from 1993 to 1997 was performed at a tertiary level, referral hospital.

Nine hundred and sixty-one infants who were delivered from 878 high-risk mothers were recruited. All of the risk factors that might have contributed to asphyxia were identified and recorded. Univariate and stepwise multiple logistic regression analysis was performed to identify significant factors that might have contributed to asphyxia, the odds ratios and 95 per cent confidence interval were computed.

Abnormal fetal heart rate pattern, thick meconium stained amniotic fluid, and premature delivery, were three common risk factors for asphyxia. The mean gestational age was 37.6 +/- 3.5 weeks, 10.5 per cent (101/961) were infants less than 33 weeks. The incidence of asphyxia was 9.7 per cent and was highest (26.7%) in infants less than 1000 g. By univariate analysis, significant relationships between perinatal factors and asphyxia were found among birth weight, gestational age, premature and breech delivery but stepwise multiple logistic regression analysis revealed that only birth weight was significantly associated with perinatal asphyxia.

In countries where resources are limited, a neonatal resuscitation team should be available for very low birth weight infants, premature and breech delivery.