Factors that Influence Re-Pregnancy Failure and Prediction Models After Complete Curettage for Missed Abortion

Background: Missed abortion (MA), a type of spontaneous abortion, has become increasingly common in early pregnancy. Retained embryos may lead to dead fetus syndrome or severe hemorrhage, affecting the physical and mental health of women. This study selected MA patients undergoing uterine evacuation to construct a predictive model for factors that influence subsequent pregnancy failure, aiming to improve patient prognosis. Methods: A retrospective analysis of 466 women with MA after a complete uterine curettage (May 2021–May 2023) was conducted. Patients were randomly divided into a modeling (326) and a validation (140) group; the modeling group was further classified by re-pregnancy outcome. Logistic regression was used to assess risk factors for re-pregnancy failure after a complete uterine curettage for MA. The nomogram model was constructed in R software. The receiver operating characteristic (ROC) curve was plotted to evaluate the discriminative power of the nomogram model. A decision curve analysis (DCA) was used to assess the clinical value of the model. Results: Among 466 women, 88 (18.89%) experienced pregnancy failure. A total of 62 (19.02%) women experienced failure in the modeling group (n = 326). Multivariate logistic regression analysis identified age, prior induced abortions, early uterine fluid accumulation during re-pregnancy, complicated polycystic ovary syndrome, and transforming growth factor beta 1 (TGFβ1) as risk factors for re-pregnancy failure after complete curettage of the uterine cavity for MA (p < 0.05), while matrix metalloproteinase 9 (MMP9) reduced the risk of re-pregnancy failure (p < 0.05). The area under the curve (AUC) of the modeling group was 0.957, and the slope of the calibration curve was close to 1, with a Hosmer-Lemeshow (H-L) test value of χ2 = 6.968 and p = 0.696. The AUC in the validation group was 0.990, and the slope of the calibration curve was close to 1, with an H-L test value of χ2 = 6.859 and p = 0.676. The DCA curve showed that the high-risk threshold probabilities for the two groups were 0.07–0.78 and 0.08–0.84, respectively. The nomogram model was then used to evaluate the clinical utility of predicting re-pregnancy failure after MA curettage. Conclusions: Age, number of previous induced abortions, early uterine fluid accumulation during re-pregnancy, complicated polycystic ovary syndrome, MMP9, and TGFβ1 are influencing factors for re-pregnancy failure after complete curettage of the uterine cavity for MA. A prediction model constructed from these factors accurately estimated the postoperative risk of recurrent pregnancy loss.