Five-Minute Apgar Scores and Its Prognostic Value for Mortality and Severe Morbidity in Very Preterm Infants: A Multinational Cohort Study.

OBJECTIVE

To examine associations between a 5-min Apgar score < 7 and severe neonatal outcomes in very preterm (VPT) infants and how results are impacted by variations in assigning Apgar scores within an international context.

DESIGN

Prospective observational population-based cohort study.

SETTING

Eleven structurally and organisationally diverse countries across Europe.

POPULATION: In total, 7900 liveborn VPT infants from the EPICE-SHIPS study.

METHODS

Descriptive statistics, logistic regression, modified Poisson regression.

MAIN OUTCOME MEASURES: Associations between 5-min Apgar scores < 7 and adverse neonatal outcomes were estimated with adjustments for perinatal characteristics. We tested for interactions by country-level prevalence of an Apgar score < 7, grouped into low (14%-16%), medium (19%-22%) and high (28%-40%).

RESULTS

20.2% of infants had 5-min Apgar score < 7 with rates of 14%-40% across countries. A score < 7 increased risks of in-hospital mortality, intraventricular haemorrhage (IVH), cystic periventricular leukomalacia (cPVL), retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD) and length of hospital stay (LHS), but not necrotising enterocolitis or late-onset infection (LOI). No interactions with country group were detected for mortality, cPVL and ROP, while associations with IVH, BPD and LHS were restricted to countries with lower prevalence of scores < 7.

CONCLUSIONS

Significant differences exist in the prevalence of low Apgar scores across countries. Their interactions with adverse outcomes demand caution when using the Apgar score in prognostic models for clinical care and research without local validation. More broadly, our findings emphasise the importance of accounting for country-specific effects in clinical assessment scores.