Abstract
PURPOSE: To investigate whether women with unexplained infertility (UI) demonstrate different demographic and IVF characteristics compared to those with other causes of infertility. METHODS: Data on 245 couples that underwent a total of 413 IVF/ICSI cycles were analyzed (UI 114 cycles, 73 women; anovulation (PCO/PCOS) 83 cycles, 51 women; tubal factor 85 cycles, 47 women; male factor 131 cycles, 74 women). Features of UI were compared versus other infertility groups, after adjustment for multiple comparisons. Generalized least squares (GLS) and random-effects logistic regression analysis were also performed. RESULTS: Live birth rates, consisting of the primary outcome, were similar in all compared infertility groups. Compared to male infertility, UI was associated with woman's older age at cycle, lower body mass index (BMI), and higher follicle-stimulating hormone (FSH). Compared to tubal infertility, UI was linked to lower endometrial thickness at oocyte retrieval and lower BMI; compared to anovulatory infertility related to PCO/PCOS, UI was linked to woman's older age, more frequent smoking, and poorer ovarian reserve tests (FSH and antral follicle count). After adjustment for other types of infertility, woman's age, age at menarche, and FSH levels, anovulatory infertility presented with higher odds of clinical pregnancy compared to UI (adjusted OR = 2.13, 95% C: 1.01-4.52). CONCLUSIONS: Infertile women with UI undergoing assisted reproduction demonstrate different demographic and clinical characteristics compared to those of other causes of infertility, albeit live birth rates are similar.