Discrepancies in the normative neonatal blood pressure reference ranges.

Numerous normative blood pressure (BP) reference ranges with considerable variation in the data have been published for neonates. This poses unique challenges for the definition and management of BP abnormalities in neonates. The aim of this study was to investigate the factors that have led to varying normative BP reference ranges in the studies conducted to date and to discuss potential study designs that would help better define the normative data. An electronic literature search was performed in 'PubMed' for articles published in English between January 1965 and February 2014 related to neonatal BP reference ranges. Common limitations found in the published studies included small sample sizes, combined use of oscillometric and intra-arterial BP measurements, lack of consideration of potentially influential factors such as postconception age, daily weight and medications, and use of data from individuals with wide ranges of gestational age, birth weight, and postconception age. Inconsistencies in the published neonatal BP reference ranges are likely due to a combination of factors related to study design. Attention to these issues should be considered when designing future multicenter studies on this topic.