Background: Survival of preterm neonates has steadily improved over the past five decades, due to changes in the neonatal intensive care. However, in Saudi Arabia, there are no written guidelines on the definition of the lower limit of viability, and there has been a call for such a limit. The aims of this study were: (1) to determine lower limits of viability and survival in extremely low birthweight (ELBW) infants, and (2) to determine incidence of neurodevelopmental and cognitive abnormalities within 3-6 years after birth.
Methods: Prospective study of all live inborn ELBW infants admitted to the neonatal unit of King Abdulaziz Medical City, Riyadh, Saudi Arabia, within 3 years [between January 1st, 2005 and December 31st, 2007] was conducted (n = 117). Data were collected on demographic and birth data, neonatal complications & interventions and death on discharge. Prospective follow up of all survivors was done, within 6 years after birth, to assess the outcome in terms of neurodevelopmental and cognitive abnormalities. Predictors of survival were determined using logistic regression model. Significance was considered at p-value ≤0.05.
Results: Of all ELBW infants, 41% died before discharge. Survival rate was directly correlated with gestational age (GA) and birthweight (p < 0.05). The 50% limits of viability were those at 25 weeks' gestation or with > 600 g. After adjusting for possible confounders, significant predictors of survival were birthweight (p = 0.001) and Apgar score (p < 0.001). The following impairments were reported during follow up of survivors: developmental delay (39.2%), cerebral palsy (36.2%), speech problems (33.3%), wasting (12.5%), intellectual disability (10%), visual problems (6.6%) and hyperactivity (5.6%).
Conclusion: More than one-third of ELBW died before discharge from NICU, and two-thirds of survivors had one or more neurodevelopmental and/or cognitive abnormalities during their first 6 years of life. The 50% limits of viability of ELBW infants were those at week 25 of gestation or with a birthweight of more than 600 g. Birthweight could be considered as more valid than gestational age in the prediction of viability of ELBW infants. The process of care of ELBW infants in Saudi Arabia may need to be revisited taking these findings into consideration.