Normative blood pressure data in the early neonatal period

There has been a temporal trend towards increased birth weight over the past three decades. This increase in birth weight may have resulted in an increase in neonatal blood pressure. Neonatal hypertension is becoming more common, especially in neonatal intensive care unit survivors. Current normative values are required to assist in diagnosis and appropriate management of neonatal hypotension and hypertension. The objective of this study was to determine normative blood pressure readings in healthy term neonates. Term neonates from the postnatal ward were enrolled from August 2003 to August 2005. Exclusion criteria included infants of mothers with preeclampsia, hypertension of any cause, gestational diabetes, type 1 diabetes mellitus and illicit substance use, infant congenital or chromosomal anomaly, admission to the neonatal intensive care unit or possible sepsis. Of the 406 infants enrolled, 218 were male. The median systolic, diastolic and mean blood pressures on day 1 of life were 65 mmHg, 45 mmHg, and 48 mmHg, respectively. On day 4, these values had increased to 70 mmHg, 46 mmHg and 54 mmHg. There was a significant elevation in blood pressure from day 1 to day 2 of life. There was no significant difference in blood pressure readings with respect to birth weight or length. The only significant difference between the sexes was a lower mean and diastolic pressure on day 2 in boys. This study has provided current normative blood pressure readings of healthy term neonates that can be used to assess both hypotension and hypertension in the term neonate. No increase in blood pressure was noted from previous studies.