More infants born extremely preterm (<28 weeks' gestation) or extremely low birthweight (<1000 g) are surviving into adulthood in recent years. Preterm adolescents have higher blood pressure (BP) than normal birthweight controls, but how their BP changes with increasing age is not known. We compared BP at 25 years and trajectories of BP (change per year) from 18 to 25 years between survivors born <28 weeks/<1000 g and normal birthweight (>2499 g) controls born in the early 1990s, when survival rates began to rise. Participants were derived from 297 consecutive survivors born <28 weeks/<1000 g in 1991 to 1992 in Victoria, Australia, and 260 contemporaneous controls. At age 25 years, ambulatory BP was measured in 151 and 119 participants, respectively. Participants born <28 weeks/<1000 g had higher 24-hour systolic (mean difference 4.5 [95% CI, 1.2-7.7 mm Hg]), diastolic (3.4 [1.5-5.2 mm Hg]), and mean BPs (3.6 [1.4-5.8 mm Hg]) compared with the controls. Similar patterns were observed for both awake and asleep periods. Asleep ambulatory BP between 18 and 25 years increased more in participants born <28 weeks/<1000 g than in controls (systolic 0.56, diastolic 0.41, and mean 0.41 mm Hg increase per year; all P<0.05). Young adults born <28 weeks/<1000 g in the post surfactant era have higher BP and an increased trajectory of ambulatory BP compared with controls. With more survivors born <28 weeks/<1000 g now reaching adulthood, these findings are important for early detection and timely management of hypertension in this high-risk population.
Keywords: blood pressure; population; premature birth; survivors; young adult.