Predictors of ongoing pregnancy after single-embryo transfer following mild ovarian stimulation for IVF

ObjectiveTo develop a prognostic model for the prediction of ongoing pregnancy after single-embryo transfer (SET) following mild stimulation for IVF in women less than 38 years of age.DesignProspective cohort study.SettingTwo fertility centers in tertiary referral university hospitals.Patient(s)A total of 152 women with an elective SET following mild ovarian stimulation (cycle day 5 start of 150 IU/day recombinant FSH and late follicular phase GnRH antagonist cotreatment).Intervention(s)Database analysis.Main outcome measure(s)Ongoing pregnancy.Result(s)The ongoing pregnancy rate per elective SET was 28% (42 of 152). In a multivariate logistic regression analysis, body mass index, the total gonadotrophin dose needed, and number of oocytes retrieved were negatively correlated whereas the availability of a top-quality embryo was positively correlated with ongoing pregnancy. The predictive ability of the model assessed by the area under the receiver operating characteristic curve was 0.68. At a probability cut-off level of 0.20 the model showed a sensitivity of 37% and a specificity of 90%.Conclusion(s)The developed prediction model for ongoing pregnancy provides an evidence-based strategy for guidance under which conditions SET may be performed. After external validation, application of the model may help to improve overall singleton pregnancy rates.