Objective To explore the pregnancy experience and mental state of women undergoing fetal surgery due to twin-to-twin transfusion syndrome. Design A mixed methods study collecting: both quantitative and qualitative data Setting The Affiliated Shengjing Hospital of China Medical University Population Women undergoing fetoscopic surgery due to Twin-to-twin transfusion syndrome Main Outcome Measures Quantitative data was collected using the Impact of Event Scale-Revised questionnaire, the Self-Rating Anxiety Scale, and the Pregnancy Stress Scale. Qualitative data was collected using a semi-structured interview Results The emotional reaction of women undergoing fetoscopic surgery due to twin-to-twin transfusion syndrome was long-term, and the adverse emotions did not diminished over time. After surgery, patients were constantly worried about the health of the fetuses,and the lack of disease information will aggravate their uncertainty and worry. Twin transfusion syndrome may also cause a post-traumatic stress reaction in women, but for protecting the surviving fetuses ,they utilized positive ways to regulate negative emotions, so postoperative worry about fetuses did not cause them much anxiety. Conclusion Gestational emotional reaction of women undergoing TTTS fetoscopic surgery is complicated. According to our research , optimizing the referral system and strengthening disease information support could be a good way for clinical staff to improve these women’s mental state during pregnancy and avoid emotion to fluctuate violently,especially for people with weaker fertility.