Exploring Lymphocyte Immunotherapy as A Treatment For Unexplained Repeated IVF Failure: A Case Study of Immune System Modulation and Positive Clinical Pregnancy

Recurrent implantation failure and repeated in vitro fertilization (IVF) failure remain major challenges in reproductive medicine. Although advances in assisted reproductive technologies have improved pregnancy outcomes, some couples fail to achieve pregnancy despite favorable reproductive parameters and the transfer of good-quality embryos, suggesting a possible role of underlying immunological factors. Lymphocyte Immunotherapy (LIT) has been proposed as an immunomodulatory treatment designed to enhance maternal immune tolerance toward paternal antigens and support successful embryo implantation. We report the case of a 33-year-old woman with a history of infertility and two previous failed IVF cycles despite adequate ovarian reserve, satisfactory reproductive potential, and normal male-factor evaluation. The male partner’s semen analysis was within normal reference ranges, and sperm DNA Fragmentation Index (DFI) was normal. No significant medical or surgical comorbidities were identified. In view of unexplained recurrent IVF failure and suspected immune-mediated implantation dysfunction, the patient underwent partner-derived Lymphocyte Immunotherapy prior to a subsequent IVF cycle. Fourteen days after embryo transfer, serum β-human chorionic gonadotropin (β-hCG) was positive at 1801.90 mIU/mL. Follow-up ultrasonography confirmed a viable intrauterine pregnancy at 6 weeks, normal dating at 8 weeks, normal nuchal translucency and nasal bone findings at 11 weeks, and a normal anomaly scan at 22 weeks. The pregnancy progressed uneventfully and resulted in the delivery of a healthy term infant at 39 weeks of gestation. This case highlights the potential role of LIT as an adjunctive treatment strategy in selected patients with unexplained recurrent IVF failure and supports further investigation into immune-based approaches for implantation failure.