Twenty four-hour blood pressure and cognitive outcomes in adolescents born extremely preterm and at term

Aim: To explore the impact of blood pressure on cognitive outcomes at 18 years of age in individuals born extremely preterm (<28 weeks' gestation) and at term (≥37 weeks' gestation). Methods: Prospective longitudinal cohort comprising 136 young adults born extremely preterm and 120 matched term controls born in Victoria, Australia in 1991 and 1992. Using linear regression, we analysed the relationships between 24-h mean ambulatory blood pressure, systolic and diastolic hypertension with cognitive outcomes. Results: For both birth groups combined, higher 24-h mean ambulatory blood pressure and systolic hypertension were associated with similar or worse cognitive outcomes. The strongest relationships were between higher 24-h mean ambulatory blood pressure and systolic hypertension with poorer general intellect, visual learning and visual memory. We found little evidence that relationships between ambulatory blood pressure and cognitive outcomes differed by birth group. Conclusion: Higher 24-h mean ambulatory blood pressure and systolic hypertension were associated with poorer cognitive outcomes in individuals born extremely preterm and at term, particularly in general intelligence and visual memory.