Toward more accurate prediction of future pregnancy outcome in couples with unexplained recurrent pregnancy loss: taking both partners into account

Objective: To identify, besides maternal age and the number of previous pregnancy losses, additional characteristics of couples with unexplained recurrent pregnancy loss (RPL) that improve the prediction of an ongoing pregnancy. Design: Hospital-based cohort study in couples who visited specialized RPL units of two academic centers between 2012 and 2020. Setting: Two academic centers in the Netherlands. Patients: Clinical data from 526 couples with unexplained RPL were used in this study. Intervention(s): None. Main Outcome Measures: The final model to estimate the chance of a subsequent ongoing pregnancy was determined using a backward selection process and internally validated using bootstrapping. Model performance was assessed in terms of calibration and discrimination (area under the receiver operating characteristic curve). Results: Subsequent ongoing pregnancy was achieved in 345 of 526 couples (66%). The number of previous pregnancy losses, maternal age, paternal age, maternal body mass index, paternal body mass index, maternal smoking status, and previous in vitro fertilization/intracytoplasmic sperm injection treatment were predictive of the outcome. The optimism-corrected area under the receiver operating characteristic curve was 0.63 compared with 0.57 when using only the number of previous pregnancy losses and maternal age. Conclusions: The identification of additional predictors of a subsequent ongoing pregnancy after RPL, including male characteristics, is significant for both clinicians and couples with RPL. At the same time, we showed that the predictive ability of the current model is still limited and more research is warranted to develop a model that can be used in clinical practice