Abstract: Objective To analyze the difference in pregnancy outcomes of twins with different chorionic pregnancies. Methods We analyzed 257 pregnant women with twins who gave birth in Wuhan Maternal and Child Healthcare Hospital from January 2021 to December 2022 and divided them into two groups according to their chorionic characteristics：the double chorionic group and the single chorionic group. The general conditions，delivery outcomes， and neonatal complications of these pregnant women were analyzed retrospectively，and the differences in pregnancy outcomes of different chorionic mothers and children were compared. Results The incidence of preterm delivery in the monochorionic group was higher than in the double-chorionic group（58. 4% vs. 43. 3%）. The difference was statistically significant（P < 0. 05）. There was no significant difference in postpartum hemorrhage（3. 9% vs. 8. 9%）and cesarean section rate（88. 3% vs. 92. 8%）between the monochorionic group and the dichorionic group（P > 0. 05）. The incidence of neonatal low body weight（72. 1% vs. 47. 5%），neonatal pneumonia（36. 4% vs. 20. 0%），neonatal hyperbilirubinemia （33. 8% vs. 22. 8%） ， and neonatal respiratory failure （15. 6% vs. 7. 5%）in the monochorionic group was higher than that in the dichorionic group. The difference was statistically significant（P < 0. 05）. There was no significant difference in the incidence of neonatal respiratory distress syndrome（8. 4% vs. 5. 8%）and ischemic hypoxic myocardial damage（17. 5% vs. 11. 7%）between the two groups（P > 0. 05）. Conclusion The incidence of preterm birth， low birth weight， neonatal pneumonia， neonatal hyperbilirubinemia，and neonatal respiratory failure are higher in the monochorionic group， which should be paid more attention to clinically.

Key words: twin pregnancy, chorionicity, pregnancy outcome