Background: There is little other than empiricle data on the reference values for blood pressure of preterm infants and what there is is unrelated to gestation and postnatal age. For 10 years we have monitored intravascular BP on all sick PT infants over the first week of life.

Subjects: 322 PT infants <37 weeks gestation. n= 17 (<26w), 47(26-28w), 177 (29-32w), 81 (33-36w) who were stable enough not to receive inotropic agents and who survived to discharge

Interventions: Intravascular BP via transducer on umbilical artery or radial artery catheter. Values stored to computer every minute (MARY system[reference]). The centiles of all mean BP data on all the subjects in 4 different gestational groups were calculated daily for the first 7 days of life

Results: Expressed as median (interquartile range) - reflecting 1.3 million data points. Table

Table 1 No caption available.
Full size table

Conclusions: In this group of infants who were not sick enough to require inotropic support and who survived to discharge, the mean BP increased over the first 4-6 days of life and there was a steady increase in the blood pressure with increasing gestation.