Objective:

Describe the measurements of systolic, diastolic and mean blood pressure in healthy term and late preterm newborns to establish normal values.

Methods:

Cross-sectional study carried out in the nursery of the Hospital Español, located in Mexico City. A sample of 551 healthy newborns were included in the study. Blood pressure (BP) measurements were taken within the first 48 hours of life with the oscillometric method. After the evaluation of normality, a descriptive analysis of the population and calculation of percentiles (25, 50 and 75) specific for each week of gestation was performed. All analyzes were performed in STATA v14.2.

Results:

Male newborns had a mean SBP value of 64.6 mmHg at week 35 of gestation, this value increased to 69.8 mmHg at week 40; the systolic blood pressure (SBP) value was 42.6 mmHg at week 35 of gestation, which decreased to 40.8 mmHg at week 40. The mean SBP values in female newborns were 65.5 mmHg at week 35, increasing to 73.5 mmHg at week 40; the diastolic blood pressure (DBP) value at week 35 of gestation was 38 mmHg, increasing to 41.3 mmHg at week 40.

Conclusions:

The BP values in healthy newborns are modified by the gestational age and sex of the patients. These results can serve as a reference for other physicians located in countries or cities with a similar altitude than the one in Mexico City.