BackgroundThe aim of this study was to evaluate the pregnancy feasibility of women with mild pulmonary hypertension according to pregnancy outcomes.MethodsThis systematic review and meta-analysis compared the differences in maternal and fetal outcomes between mild and moderate-to-severe pulmonary hypertension. Relevant English and Chinese literature were searched in the PubMed, Embase, Cochrane Central Register of Controlled Trials (COCHRANE), CNKI, WanFang Data, and VIP databases between January 1st, 1990 and April 18th, 2023, and the references of the included articles and relevant systematic reviews were reviewed to determine whether studies were missed. The inclusion criteria were randomized controlled and observational studies (including case-control studies and cohort studies) examining maternal and fetal pregnancy outcomes with pulmonary hypertension. Conference abstracts, case reports, case series reports, non-comparative studies, and review articles were excluded.ResultsThis meta-analysis included 32 studies. In this study, maternal and fetal outcomes were better in the mild pulmonary hypertension group than in the moderate-to-severe group. Regarding maternal mortality, the mild group was much lower than the moderate to severe group. We found a significant decrease in maternal mortality in the mild group after 2010. However, no significant difference in maternal mortality before and after 2010 was observed in the moderate to severe group. Cardiac complications, ICU admission, neonatal preterm birth, small for gestational age infants, low birth weight infants, neonatal asphyxia, and neonatal mortality were significantly lower in the mild pulmonary hypertension group than in the moderate to severe pulmonary hypertension group. The cesarean section rates of the two groups were similar. However, the vaginal delivery rate in the mild pulmonary hypertension group was significantly higher than that in the moderate to severe pulmonary hypertension group.ConclusionsThis meta-analysis confirmed that pregnancies with mild pulmonary hypertension had significantly better maternal and fetal outcomes than those with moderate to severe pulmonary hypertension. For patients with mild pulmonary hypertension and good cardiac function, continued pregnancy or even delivery should be considered under multidisciplinary monitoring. However, maternal and fetal complications with moderate to severe pulmonary hypertension significantly increase. Hence, it is essential to evaluate pregnancy risk and terminate it in time.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12884-023-05752-w.