Pulmonary hypertension(PH)is commonly seen in preterm infants with bronchopulmonary dysplasia(BPD)and is significantly associated with increased mortality.The pathophysiological basis of PH is pulmonary vascular dysplasia or remodeling, and airways hyperresponsiveness.At present, management of BPD-PH should be comprehensive supportive therapy and focus on targeted pharmacotherapies, including various pulmonary vasodilators with different vasoactive mechanisms, such as phosphodiesterase inhibitors, endothelin receptor antagonists and prostaglandins analogs.However, although expert consensus recommends targeted pulmonary arterial hypertension therapy, high-quality clinical studies on the safety and efficacy of these drugs are few.Pulmonary vascular remodeling inhibitors and stem cell therapy have enormous potential to reduce pulmonary hypertension and further research and more data are needed.

Objective:To summarize the clinical characteristics of neonatal cerebral infarction and its risk factors, so as to provide a reference for clinical diagnosis and early prevention of the disease.Methods:This study retrospectively analyzed the demographic data, clinical manifestations and brain imaging features of neonates with cerebral infarction ( n=45) admitted to the Department of Neonatal Critical Care Medicine of the Affiliated Children's Hospital of Xi'an Jiaotong University from June 2012 to July 2020. Ninety newborns without cerebrovascular disease matched for date of birth and gestational age were selected as the control. Two independent sample t-test, rank-sum test, Chi-square or corrected Chi-square test were used for univariate analysis and binary logistic regression were applied for analyzing the risk factors for neonatal cerebral infarction. Results:A total of 45 infants with clinically diagnosed neonatal cerebral infarction were enrolled, including eight small for gestational age and three macrosomia infants. The median age at disease onset was 1 d (1-2 d). There were 71% (32/45) presenting with convulsions as the first symptom, 4% (2/45) admitted with apnea and respiratory distress as the chief complaints, respectively,11% (5/45) having poor response and 9% (4/45) showing no obvious clinical manifestations. Cranial MRI and magnetic resonance angiography identified left hemisphere lesion in 25 cases (56%), right hemisphere lesion in 16 (36%) and both in four (9%). Thalamus and basal ganglia were involved in 11 cases. The lesions were supplied by middle cerebral artery [38% (17/45)], anterior cerebral artery ( n=1), posterior cerebral artery ( n=4), anterior and middle cerebral arteries ( n=4), middle and posterior cerebral arteries ( n=16), or anterior, middle and posterior cerebral arteries ( n=3). Univariate analysis showed that the proportions of small for gestational age [18% (8/45) vs 6% (5/90), χ 2=5.15], cesarean section after failure of trial of labor [18% (8/45) vs 1% (1/90), χ 2=10.85], meconium stained amniotic fluid [33% (15/45) vs 9% (8/90), χ 2=12.68], fetal distress [20% (9/45) vs 3% (3/90), χ 2=8.34] and neonatal asphyxia [16% (7/45) vs 2% (2/90), χ 2=6.56] were all higher in the infarcted infants than those in the control (all P<0.05). Binary logistic regression analysis revealed that small for gestational age ( OR=3.981, 95% CI: 1.075-14.742, P=0.039), cesarean section after failure of trial of labor ( OR=17.959, 95% CI: 2.032-158.698, P=0.009) and fetal distress ( OR=5.756, 95% CI: 1.129-29.331, P=0.035) were independent risk factors for neonatal cerebral infarction. Conclusions:Most neonates with cerebral infarction would have convulsions initially, while some are asymptomatic. Middle cerebral arteries are often involved in the lesion. The risk of this disease may be increased in small for gestational age infants, cesarean section after failure of trial of labor and fetal distressed cases.