A Nomogram Model for Predicting Clinical Pregnancy after Fresh IVF/ICSI-ET in Patients with Infertility and Endometriosis.

Objective: To determine the clinical and embryo laboratory factors that affect the clinical pregnancy rate of infertile patients with endometriosis (EMs), and establish a model for predicting clinical pregnancy.

Study design: An observational study. Place and Duration of the Study: Reproductive Medicine Centre, Jiangxi Provincial Maternal and Child Health Hospital, China, from January 2016 to December 2023.

Methodology: Inclusion criteria were EMs patients diagnosed and treated through laparoscopic surgery, aged 22 - 37 years, who did not undergo surgery within 3 months before oocyte retrieval, and received fresh embryo transfer; and the causes of infertility included male factors, tubal infertility, intrauterine adhesions, and others. The exclusion criteria were EMs patients with combined uterine adenomyosis, chromosomal abnormalities, abnormal uterine structure, endocrine diseases, cardiovascular diseases and autoimmune diseases. The research variables included clinical and embryonic factors that affect clinical pregnancy rates, such as age, duration of infertility, type of infertility, and sex hormone levels. The outcome variable was the clinical pregnancy rate.

Results: The clinical pregnancy rate was 61.84%. This predictive model was built on the basis of the number of high-quality cleavage embryos, number of embryos transferred, progesterone on HCG day, infertility duration, female age, number of oocytes retrieved, and body mass index showing good calibration and discriminatory abilities, with the area under the curve of receiver operating characteristic curve of 0.641 (95% CI = 0.599 - 0.684) for training set and 0.583 (95% CI = 0.515 - 0.650) for testing set. The Hosmer-Lemeshow test showed no significant difference (p >0.05) between the predicted and the true clinical pregnancy probabilities. The clinical decision curve analysis showed that both the training and testing sets achieved maximum net benefit within a threshold probability range of 0.4 - 0.8, indicating good clinical efficacy within this threshold probability range.

Conclusion: The model for predicting clinical pregnancy in patients with EMs after fresh IVF/ICSI-ET had high accuracy, and can provide useful guidance for clinical doctors and individual adjuvant treatment of patients.

Key words: Endometriosis, Predictive model, Clinical pregnancy, Nomogram, In vitro fertilisation.