Nomogram to predict pregnancy outcomes of emergency oocyte freeze-thaw cycles

Existing clinical prediction models for in vitro fertilization are based on the fresh oocyte cycle, and there is no prediction model to evaluate the probability of successful thawing of cryopreserved mature oocytes. This research aims to identify and study the characteristics of pre-oocyte-retrieval patients that can affect the pregnancy outcomes of emergency oocyte freeze-thaw cycles.

Data were collected from the Reproductive Center, Peking University Third Hospital of China. Multivariable logistic regression model was used to derive the nomogram. Nomogram model performance was assessed by examining the discrimination and calibration in the development and validation cohorts. Discriminatory ability was assessed using the area under the receiver operating characteristic curve (AUC), and calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test and calibration plots.

The predictors in the model of "no transferable embryo cycles" are female age (odds ratio [OR] = 1.099, 95% confidence interval [CI] = 1.003-1.205, P = 0.0440), duration of infertility (OR = 1.140, 95% CI = 1.018-1.276, P = 0.0240), basal follicle-stimulating hormone (FSH) level (OR = 1.205, 95% CI = 1.051-1.382, P = 0.0084), basal estradiol (E2) level (OR = 1.006, 95% CI = 1.001-1.010, P = 0.0120), and sperm from microdissection testicular sperm extraction (MESA) (OR = 7.741, 95% CI = 2.905-20.632, P < 0.0010). Upon assessing predictive ability, the AUC for the "no transferable embryo cycles" model was 0.799 (95% CI: 0.722-0.875, P < 0.0010). The Hosmer-Lemeshow test (P = 0.7210) and calibration curve showed good calibration for the prediction of no transferable embryo cycles. The predictors in the cumulative live birth were the number of follicles on the day of human chorionic gonadotropin (hCG) administration (OR = 1.088, 95% CI = 1.030-1.149, P = 0.0020) and endometriosis (OR = 0.172, 95% CI = 0.035-0.853, P = 0.0310). The AUC for the "cumulative live birth" model was 0.724 (95% CI: 0.647-0.801, P < 0.0010). The Hosmer-Lemeshow test (P = 0.5620) and calibration curve showed good calibration for the prediction of cumulative live birth.

The predictors in the final multivariate logistic regression models found to be significantly associated with poor pregnancy outcomes were increasing female age, duration of infertility, high basal FSH and E2 level, endometriosis, sperm from MESA, and low number of follicles with a diameter >10 mm on the day of hCG administration.