Study design and participants
This was a single-center, non-randomized, prospective, propensity-matched, comparative study registration of female patients who underwent MVR at the Cardiothoracic Department of Ain Shams University, Cairo, Egypt, from January 2010 to February 2020.  Matched pairs based on identical or very similar propensity scores were compared in subsequent analyses. Logistic regression analysis based on explanatory variables was used for calculating the propensity score for each subject. Propensity score matching is an estimation method applied to situations, such as pregnancy, for which randomized clinical trials are unlikely to be performed.[8]
This study was approved by the local ethics committee and was conducted in accordance with the Helsinki Declaration. All patients provided written informed consent before the surgical procedures.