Research article
Association of Apgar score at five minutes with long-term neurologic disability and cognitive function in a prevalence study of Danish conscripts
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* Corresponding author: Vera Ehrenstein ve@dce.au.dk
1 Department of Clinical Epidemiology, Aarhus University Hospital, Science Centre Skejby, Olof Palmes Allé 43-45, 8200 Aarhus N, Denmark
2 Department of Epidemiology, Boston University School of Public Health, 715 Albany Street, Boston, MA 02118, USA
3 RTI Health Solutions, Research Triangle Park, NC 27709, USA
BMC Pregnancy and Childbirth 2009, 9:14 doi:10.1186/1471-2393-9-14
Published: 2 April 2009Abstract
Background
Apgar score is used for rapid assessment of newborns. Low five-minute Apgar score has been associated with increased risk of severe neurologic outcome, but data on milder outcomes, particularly in the long term, are limited. We aimed to examine the association of five-minute Apgar score with prevalence of neurologic disability and with cognitive function in early adulthood.
Methods
We conducted a prevalence study among draft-liable men born in Denmark in 1978–1983 and presenting for the mandatory army evaluation in a northern Danish conscription district. We linked records of this evaluation, which includes medical exam and intelligence testing, with the conscripts' records in the Medical Birth Registry, containing perinatal data. We examined prevalence of neurologic disability and of low cognitive function according to five-minute Apgar score.
Results
Less than 1% (136/19,559) of the conscripts had 5-minute Apgar scores <7. Prevalence of neurologic disability was 2.2% (435/19,559) overall; among conscripts with Apgar scores <7, 7–9, and 10 (reference), it was 8.8%, 2.5%, and 2.2% respectively. The corresponding prevalences of low cognitive function (intelligence test score in the bottom quartile) were 34.9%, 27.2%, and 25.0%. The outcomes were more prevalent if Apgar score <7 was accompanied by certain fetal or obstetric adversities. After accounting for perinatal characteristics, 5-mintue Apgar score <7 was associated with prevalence ratios of 4.02 (95% confidence interval: 2.24; 7.24) for neurologic disability and 1.33 (0.94; 1.88) for low cognitive function.
Conclusion
A five-minute Apgar score <7 has a consistent association with prevalence of neurologic disability and with low cognitive function in early adulthood.