Analysis of IVF/ICSI assisted pregnancy Outcomes in TS Patients with Low-Level and High-Level Mosaic Cell Lines

Background: Turner syndrome characterized by short stature and premature ovarian failure (POF) that often leads to infertility. Unlike non-mosaic 45,X TS patients with severe ovarian dysfunction, mosaic TS patients may retain partial ovarian function due to the presence of normal 46,XX cell lines, enabling potential spontaneous or assisted pregnancy via IVF/ICSI. However, limited research has focused on whether the level of mosaicism (low vs. high) affects IVF/ICSI outcomes in these patients, leaving a gap in evidence for clinical decision-making. This study aimed to compare the assisted pregnancy outcomes of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) in mosaic TS patients with low-level and high-level mosaic cell lines. Methods: This retrospective cohort study analyzed data from 66 patients diagnosed with mosaic Turner syndrome (TS) who underwent in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) for assisted pregnancy at the Reproductive Health Hospital of the Third Affiliated Hospital of Zhengzhou University, from November 2015 to October 2025. Mosaic TS patients were divided into 2 groups according to the mosaicism level: patients with low-level mosaic cell lines [≤10%] (N = 45), and patients with high-level mosaic cell lines [＞10%] (N = 21). The study compared embryo laboratory outcomes and clinical outcomes between the two groups. Result(s): The number of follicles larger than 16mm on the day of HCG in TS patients with low-level mosaic cell lines ( 6.24±3.15) was significantly higher than that in patients with low-level mosaic cell lines (4.00±2.19) ( p =0.001), and the number of follicle oocyte index (FOI) in TS patients with low - level mosaic cell lines(0.90±0.48) was significantly higher than in patients with high - level mosaic cell lines(0.65±0.37) ( p =0.041). There were no significant difference in the high-quality embryo rate, available embryo rate, blastocyst formation rate, pregnancy rate, live birth rate, cumulative pregnancy rate, and cumulative live birth rate between the two groups. After multivariate linear regression analysis, there were also no significant difference in the high-quality embryo rate, blastocyst formation rate, and available embryo rate between TS patients with low-level and high-level mosaic cell lines. After multivariate logistic regression analysis, only female age exerted a significant negative effect on the cumulative live birth rate (aOR=0.927, 95% CI: 0.854-0.996, P =0.02), none of other confounding factors exhibited an independent effect on any of the outcomes. Conclusion(s): Compared with mosaic TS patients with low-level mosaic cell lines, there were no significant difference in the assisted pregnancy outcomes of IVF/ICSI in mosaic TS patients with high-level mosaic cell lines.