The factors affecting the pregnancy outcome of RPL patients are complex and diverse, but it is worth mentioning that a comprehensive review of guidelines states that genetic thrombophilia, vaginal infections, and immunologic and male factors of infertility are not recommended as part of routine RPL investigations and there is also some controversy about the need for ovarian reserve testing, thyroid disease, screening for diabetes or hyperhomocysteinemia, measurement of prolactin levels, and endometrial biopsy [20]. This evidence concerns the gene PRL and diabetes mellitus.