Abstract: Objective To explore the correlation between the expression of transforming growth factor-β1 (TGF-β1), ɑ-smooth muscle actin (α-SMA) in wound exudate and postoperative recurrence after hysteroscopic separation of intrauterine adhesions. 
Methods A prospective cohort study was conducted on 98 female patients of reproductive age who underwent hysteroscopic separation of uterine adhesions, and they were divided into recurrence (n=33) and non-recurrence (n=65) groups according to postoperative recurrence. The general data, TGF-β1 and α-SMA levels in wound exudate at 3 h, 9 h and 24 h after surgery were compared between the two groups. The Spearman method was used to analyze the relationship between the levels of TGF-β1 and α-SMA in wound exudate and recurrence at 3 h, 9 h, and 24 h after surgery, and logistic regression analysis was used to analyze the relevant influencing factors of recurrence after uterine adhesions separation surgery. The interaction coefficients γ and OR values were used to analyze the interaction of TGF-β1 and α-SMA expression in wound exudate on postoperative recurrence, and R language was used to plot the nomogram prediction model for recurrence after uterine adhesion separation. The predictive efficacy of the nomogram model was evaluated using the receiver operating characteristic (ROC) curve, and the clinical utility of the nomogram model was evaluated using decision curve analysis (DCA). 
Results There were more patients with severe uterine adhesions, history of induced abortion or curettage ≥2 times, and a history of other uterine surgery in the recurrence group than in the non-recurrence group (P＜0.05). With the extension of time, the expression levels of TGF-β1 and α-SMA in the wound exudate of both groups showed an increasing and then decreasing trend, reaching a peak at 9 h after surgery; the expression levels of TGF-β1 and α-SMA in the wound exudate of the recurrence group were higher than those of the non-recurrence group, and there was a statistically significant difference in the interaction between groups, time points, and time points between groups (P＜0.05). Spearman analysis showed that TGF-β1 and α-SMA expression in wound exudate at 3 h, 9 h, and 24 h after surgery were positively correlated with postoperative recurrence (r=0.742, 0.922, 0.867; 0.659, 0.880, 0.823, all P＜0.001). The results of logistic regression analysis showed that the degree of severe uterine adhesions, a history of induced abortion or curettage ≥ 2 times, a history of other uterine surgeries, and TGF-β1 and α-SMA in the wound exudate at 9 h after surgery are all risk factors for recurrence of uterine adhesions after separation surgery (P＜0.05). Interaction analysis showed that TGF-β1 and α-SMA were superphase multiplicative models, and α-SMA had a positive interaction effect on the effect of TGF-β1 (P＜0.05). Nomogram prediction model plotted for recurrence after uterine adhesions separation surgery showed a predictive risk ability index (C-index) of 0.973, a predictive sensitivity of 93.93%, and a specificity of 92.31%. DCA analysis showed that the nomogram model had the best positive net clinical benefit (P＜0.05). 
Conclusion TGF-β1 and α-SMA expression in wound exudate after hysteroscopic separation of uterine adhesions in women of childbearing age is associated with postoperative recurrence, and α-SMA has a positive interaction on the effect of TGF-β1, and the nomogram model containing TGF-β1 and α-SMA has high value and clinical utility in predicting postoperative recurrence, which can provide reference for subsequent clinical decision making. 

Key words: women of childbearing age, hysteroscopic separation of uterine adhesions, transforming growth factor beta 1, α-SMA