Intrauterine adhesion after missed miscarriage evacuation: efficacy of different estrogen doses on incidence and risk factors.

Objective: To compare the efficacy of different doses of estradiol valerate in preventing intrauterine adhesion (IUA) incidence and promoting endometrial recovery after curettage for retained abortion.

Methods: A total of 188 patients who underwent Missed Miscarriage (MM) by curettage were retrospectively assigned to three groups based on the preoperative estradiol valerate dosage: Group A (3 mg/day), Group B (5 mg/day), and Group C (no estrogen). Postoperative outcomes, including IUA incidence (assessed by hysteroscopy), endometrial thickness (transvaginal ultrasound), menstrual recovery, and adverse reactions, were compared among groups. Logistic regression and ROC curve analysis were used to identify independent risk factors for IUA.

Results: Group B showed the lowest IUA incidence (4.84% vs. 7.14% in Group A and 21.43% in Group C, P < 0.001), greater endometrium thickness at 14 days postoperatively, and shorter menstrual recovery time (P < 0.001). Preoperative endometrial thickness < 4 mm and a history of IUA were identified as independent risk factors (AUC = 0.760). The incidence of adverse reactions did not differ significantly among the groups (P > 0.05).

Conclusion: Preoperative administration of 5 mg/day estradiol valerate significantly reduces IUA incidence and enhances endometrial recovery after curettage. A thin endometrium and prior IUA history are key risk factors for postoperative adhesion formation.