Factors Influencing Treatment Success in Unexplained Infertility: A Narrative Review

Background Unexplained infertility is a common diagnosis among couples struggling to conceive, accounting for approximately 30–40% of infertility cases. Despite advancements in reproductive medicine, predicting treatment success remains challenging. Objective This narrative review aimed to synthesize evidence on factors influencing treatment success in unexplained infertility and provide insights for optimizing clinical and policy approaches. Methods A narrative search was conducted on PubMed, Cochrane Database and Google Scholar to identify studies investigating prognostic factors and treatment outcomes in unexplained infertility. Results Seven studies involving over 1,800 couples were included in the narrative review. Female age, duration of infertility, history of miscarriage, number of treatment cycles attempted, duration of stimulation, pre-ovulatory follicle count, follicular size, endometrial thickness, endometrial pattern, total motile sperm count, smoking status, and socioeconomic status were significant predictors of success. Success rates plateaued after three intrauterine insemination (IUI) cycles, prompting a transition to in-vitro fertilization (IVF) for improved outcomes. Conclusions Treatment success in unexplained infertility is influenced by a combination of biological, lifestyle, and socioeconomic factors. Personalised treatment strategies and early intervention are critical for optimising outcomes.