Factors influencing apnea and bradycardia of prematurity - implications for neurodevelopment

Abstract

Background: Apnea and bradycardia of prematurity (ABP) are possible risks towards damage of the developing brain.

Objectives: To characterize the influence of neonatal factors on ABP and to determine the relationship of ABP to neurodevelopmental outcome.

Methods: ABP was described in very low birth weight infants (n = 83) using the frequency and severity of ABP episodes with a clinical score considering heart rate, oxygenation, duration and interventions performed during each episode. Neonatal factors were analyzed for their relationship to ABP using regression analysis. Neurodevelopment was investigated using the Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) of the Bayley Scales of Infant Development II at a corrected age of 13 months. Power of ABP parameters to predict outcome was assessed by logistic regression analysis.

Results: ABP typically started within the first week after birth. Spontaneous resolution occurred at a postmenstrual age (PMA) of 36.0 +/- 2.2 (31.1-44.1) weeks. A delayed resolution (>36 weeks PMA) and a higher average daily ABP score during a defined developmental period (31-37 weeks PMA) were associated with a higher incidence of unfavorable outcome (MDI or PDI <69 or death).

Conclusion: ABP is an age-specific phenomenon. However, more severe courses than expected for PMA or the resolution at a later PMA indicated an increased risk of neurodevelopmental disturbances at a corrected age of 13 months.