Blood pressure in the first year of life in healthy infants born at term

Neonatal hypertension occurs in up to 2% of neonatal intensive care survivors and in up to 3% of all neonates. Normal blood pressure (BP) measurements are required to diagnose and manage appropriately both hypotension and hypertension in the neonate and infant. The aim of this study was to provide normative BP measurements during the first year of life of healthy infants born at term, using an oscillometric method. Neonates were enrolled from August 2003 to August 2005. Exclusion criteria included: infants of mothers with hypertension or diabetes of any type, use of illicit substances, congenital or chromosomal anomaly, admission to the neonatal intensive care unit or possible sepsis. There were 406 infants enrolled, with 150 children followed at 6 months of age and 118 children at 12 months of age. There were no differences in BP measurements at 6 months or 12 months of age by gender, weight or height. A BP measurement above the 90th percentile on day 2 or at 6 months was not predictive of a BP above the 90th percentile at 12 months of age. Higher systolic and diastolic measurements at 6 months and 12 months were found, in comparison to those in previous studies using ultrasonic devices. The findings of this study provide normative BP values for infants during their first year of life, using the oscillometric method, the most frequently used method in paediatric, neonatal intensive care and emergency departments.