Objective: To investigate the outcomes of fetuses or neonates of pregnant women with premature ventricular contractions (PVCs). Design: Prospective cohort study. Setting: University-affiliated tertiary hospital. Population: 6, 148 pregnant women with normal cardiac structure and function and 103 with a PVC burden >0.5% among them. Methods: 103 pregnant women with PVCs were divided into two groups based on the presence or absence of adverse fetal or neonatal events. The adverse outcomes were compared between the groups. Main outcome measures: Adverse fetal and neonatal events: premature birth (<37 weeks gestation), small-for-gestational-age birth weight (<10th percentile for gestational age or <2500 g), respiratory distress syndrome, intraventricular hemorrhage and fetal death (after 20 weeks gestation and before birth). Results: A total of 17 adverse events (12 cases) occurred among 103 pregnant women with PVCs, which was significantly higher than that among women without PVCs (11.65% vs. 2.93%, p<0.01). Compared with that of the women without adverse events, the median PVC burden of women with adverse fetal or neonatal outcomes was significantly higher (9.02% vs. 2.30%, p<0.01). Multivariate logistic regression analysis demonstrated that PVC burden was associated with adverse fetal or neonatal outcomes among pregnant women with PVCs (OR: 1.34, 95% CI (1.11-1.61), p<0.01). Conclusions: Frequent PVCs have adverse effects on pregnancy, and the PVC burden might be an important factor associated with adverse fetal and neonatal outcomes among pregnant women with PVCs. Our cohort study indicated that the higher the PVC burden is, the higher the likelihood of adverse events would be.