Objective:To investigate the effect of early second-look office hysteroscopy combined with intrauterine balloon dilatation on prognosis and pregnancy rate for women with intrauterine adhesions. Methods:A retrospective analysis of 156 women diagnosed with intrauterine adhesions by hysteroscopy at Shenyang Women's and Children 's Hospital, China, from April 2017 to January 2019. The study women underwent intrauterine balloon dilatation 10 days after transcervical resection of adhesion (TCRA) and hysteroscopy 20 days after TCRA (n=81). The control women underwent hysteroscopy 3 months after TCRA (n=75).Estrogen and aspirin were routinely administered postoperatively to all women. Data, including American Fertility Society (AFS) scores assessed by hysteroscopy, endometrial thickness measured by ultrasound, and menstruation and pregnancy outcomes assessed by interview, were compared between the two groups. Results:The degree of intrauterine adhesions, menstrual status, and endometrial thickness were improved in both groups after TCRA. Greater improvement in AFS score, menstruation, and endometrial thickness was observed in the study group than in the control group. After follow-up, more women in the study group achieved pregnancy (48.1% vs 30.7%, P<0.05). Conclusion:Early second-look of hysteroscopy combined with intrauterine balloon dilatation after hysteroscopic TRCA might improve the prognosis and postoperative pregnancy rate for women with intrauterine adhesions. K E Y W O R D S Balloon dilatation; Early second-look; Intrauterine adhesion; Prognosis; Reproductive outcomes; Transcervical resection of adhesion 1 | INTRODUCTION Intrauterine adhesions (IUA), also known as Asherman syndrome, are a common cause of secondary infertility among women of childbearing age. Endometrial damage caused by intrauterine operations or infections are the major causes of IUA, which lead to partial or complete occlusion of the uterine cavity. 1 IUAs are often secondary to intrauterine operations such as dilation and curettage. 2 Most effected women have hypomenorrhea, amenorrhea, and periodic abdominal pain, but a few also have normal menstruation. 2,3 Due to the high rate of induced abortion in China, the incidence of IUA is also increasing. 4 The prevalence of IUA is reported to be approximately | 193 Sun ET AL.20% after induced abortion, but rises to 40% for women with multiple intrauterine operations. 5Hysteroscopy is the gold standard for clinical diagnosis and treatment of IUA, 6 and most confirmed cases are treated by transcervical resection of adhesion (TCRA). However, the recurrence rate is up to 62.5%. 7 Several methods have been reported for preventing IUA recurrence, such as hyaluronic acid gel, artificial cycle hormone therapy, intrauterine balloon, and intrauterine devices; however, the effects are still uncertain. 8 Therefore, it is important to find a standardized strategy for managing women with IUA after TCRA surgery. Xu et al. 9 reported that early second-look hysteroscopy after hysteroscopic adhesiolysis (within...