Abstract
BACKGROUND: Multiple pregnancies are an important complication of assisted reproductive technology (ART). The present study aims to indentify the risk factors for multiple pregnancies independent of the number of transferred embryos. MATERIALS AND METHODS: This retrospective study reviewed the medical records of patients who underwent intracytoplasmic sperm injection (ICSI) cycles in Royan Institute between October 2011 and January 2012. We entered 12 factors that affected the number of gestational sacs into the poisson regression (PR) model. Factors were obtained from two study populations-cycles with double embryo transfer (DET) and cycles that transferred three embryos (TET). We sought to determine the factors that influenced the number of gestational sacs. These factors were entered into multivariable logistic regression (MLR) to identify risk factors for multiple pregnancies. RESULTS: A total of 1000 patients referred to Royan Institute for ART during the study period. We included 606 eligible patients in this study. PR analysis demonstrated that the quality of transferred embryos and woman's age had a significant effect on the number of observed sacs in patients who underwent ICSI with DET. There was no significant predictive variable for multiple pregnancies according to MLR analysis. Our findings demonstrated that both regression models (PR and MLR) had the same outputs. A significant relation existed between age and fertilization rate with multiple pregnancies in patients who underwent ICSI with TET. CONCLUSION: Single embryo transfer (SET) should be considered with the remaining embryos cryopreserved to prevent multiple pregnancies in women younger than 35 years of age who undergo ICSI cycles with high fertilization rates and good or excellent quality embryos. However, further prospective studies are necessary to evaluate whether SET in women with these risk factors can significantly decrease multiple pregnancies and improve cycle outcomes.