Abstract
BACKGROUND: Women who undergo in vitro fertilization (IVF) cycles should successfully go via multiple stages (i.e., clinical pregnancy, no abortion under 12 weeks, no abortion under 20 weeks, and delivery) to achieve a live birth. In this study, data from multiple IVF cycles and its multiple stages were reanalyzed to illustrate the success factors associated with various stages of IVF cycles in a population of Iranian infertile women. MATERIALS AND METHODS: This historical cohort study includes 3676 assisted reproductive technology (ART) cycles. Covariates take into account in this study were women's age, type of infertility (primary, secondary), body mass index (BMI), cause of infertility, history of abortion, duration of infertility, number of oocytes, number of embryos, fertilization rate, semen factors (Spermogram) and having polycystic ovarian syndrome (PCOS) during IVF cycles. Joint modeling was fitted to apply informative cluster size. RESULTS: Increasing age un women was associated with an increase in the BMI and a positive history of abortion and PCOS, and also, an increase in the number of treatment cycles, while in men was associated with the negative spermogram. With the increase in the number of treatment cycles, the result of the IVF success decreased, but with the increase in the number of embryos, fertilization rate and also, quality and / or quantity parameters of spermogram, we encountered with an increase in the IVF success rate. CONCLUSION: It seems that a joint model of the number of treatment cycles and the result of IVF is a valuable statistical model that does not ignore the significant effect of cycle numbers, while this issue is ignored usually in the univariate models.