Abstract： Objective To explore the primary etiology of pregnancy complicated with pulmonary hypertension,analyze the pregnancy outcome and related influencing factors of patients,and provide new evidence-based medical data for guiding the pregnancy management of these patients.Methods A total of 57 pregnant women with pulmonary hypertension who terminated their pregnancy in the General Hospital of Northern Theater Command were selected and divided into the mild group(26 cases),the moderate group(20 cases)and the severe group(11 cases)according to the severity of pulmonary hypertension,and 138 pregnant women with normal pulmonary artery pressure during the same period were selected as the control group.The clinical data of pregnant women in all groups were collected and compared,and the primary etiology of pulmonary hypertension,the pregnancy outcome of patients with different severity of pulmonary hypertension and its related influencing factors were analyzed.Results Congenital heart disease(CHD)was the main primary etiology of pregnant women with pulmonary hypertension,accounting for 63.2%.There was significant difference in the proportion of patients with complex CHD in different groups(P<0.05).The proportion of patients with grade Ⅲ to Ⅳ heart function in the severe group was significantly higher than those in the control group,the mild group and the moderate group,with statistically significant differences(P<0.05).The proportion of patients with abnormal electrocardiogram in the severe group was higher than those in the mild group and the control group,and the differences were statistically significant(P<0.05).The delivery rate of full-term live infants in the control group and the mild group were much higher than those in the moderate group and the severe group,and the differences were statistically significant(P<0.05).The stillbirth rate in the severe group was higher than those in the other groups,and the differences were statistically significant(P<0.05).The neonatal asphyxia rate in the control group and the mild group were lower than those in the moderate group and the severe group,and the differences were statistically significant(P<0.05).The birth weight of newborns in the control group and the mild group were higher than those in the moderate group and the severe group,and the differences were statistically significant(P<0.05).Conclusion The most common primary etiology of pregnancy complicated with pulmonary hypertension is CHD.Pregnant women with mild or moderate pulmonary hypertension have lower risk of adverse pregnancy outcomes than pregnant women with severe pulmonary hypertension.Doppler two-dimensional ultrasound evaluation and monitoring of pulmonary artery pressure of pregnant women can be used to intervene in time to improve pregnancy and fetal outcome.