Blood pressure in preterm infants with bronchopulmonary dysplasia in the first three months of life.

Background: Neonatal hypertension is common in preterm infants with bronchopulmonary dysplasia (BPD). Our study aimed to examine blood pressure variation in the first three months of life in preterm BPD patients.

Methods: We conducted a retrospective, single-centre study at the Neonatal Intensive Care Unit of the University of Szeged, Hungary. We collected blood pressure data from 26 preterm infants (born at < 30 weeks gestation) with moderate or severe BPD over three years (2019-2021). We calculated the BPD group's daily average blood pressure values and used previously defined normal blood pressure values from a preterm patient group born at < 30 weeks gestation as a reference. We used 19,481 systolic, diastolic and mean blood pressure measurement data separately to calculate daily average blood pressures.

Results: We found a statistically significant correlation between the blood pressure values of the BPD patient group and the reference data. The difference between the blood pressure curve of the group with BPD and that of the reference group was also statistically significant. We also analysed individual patients' daily average blood pressure values and found that 11 patients (42%) had hypertensive blood pressure values for three or more days within the first 90 days of life. Within this group, our statistical analysis showed a 25% chance of acute kidney injury.

Conclusion: The blood pressure of the BPD group not only correlated with but also significantly differed from the reference data. Hypertension lasting three or more days occurred more frequently in patients with acute kidney injury accompanied by BPD.