Endocrine disorders [e.g., untreated thyroid disease, uncontrolled diabetes, or variations in the prolactin level (Timeva et al., 2014)] have been associated to RIF, as well as other comorbidities like hereditary thrombophilias (Azem et al., 2004), [...]

[...] and Preimplantational Genetic Diagnosis (PGD) in which a biopsy of the embryo is performed in order to identify the embryos that carry hereditary diseases.