RESUMEN
Objective:To study the risk factors and prognosis of pulmonary hypertension(PH) associated with bronchopulmonary dysplasia (BPD) in extremely preterm infants(EPIs).Methods:From January 2020 to December 2021, EPIs [gestational age (GA) <32 w] with BPD admitted to NICU of our hospital were retrospectively assigned into two groups: BPD with late-onset PH(PH group) and BPD without late-onset PH(non-PH group). Their general condition, treatment and prognosis were compared and the risk factors of late-onset PH were analyzed.Results:A total of 229 EPIs with BPD were enrolled, including 24(10.5%) in the PH group and 205(89.5%) in the non-PH group. The PH group had significantly smaller GA [(27.9±2.3) w vs. (28.7±1.8) w], longer mechanical ventilation [42.0(16.0, 84.0) d vs. 9.0(2.0, 23.0) d], longer hospital stay [100.5(86.3, 142.0) d vs. 77.0(56.5, 96.5)d],higher incidence of early-onset PH(54.2% vs. 9.3%) and higher mortality rate(33.3% vs. 9.8%) than the non-PH group ( P<0.05). Multivariate logistic regression analysis showed prolonged mechanical ventilation ( OR=1.046, 95% CI 1.011~1.064), early-onset PH ( OR=5.414, 95% CI 1.796~16.323) were independent risk factors for BPD with late-onset PH. 8(33.3%) patients in the PH group died, including 2 with grade Ⅱ BPD and 6 grade Ⅲ BPD. Conclusions:Prolonged mechanical ventilation and early-onset PH are independent risk factors for late-onset PH in BPD infants. BPD infants with late-onset PH have longer hospital stay, higher mortality and worse prognosis.