Recurrent pregnancy loss: Definitions, epidemiology, and prognosis

Recurrent pregnancy loss (RPL) is defined by the American Society for Reproductive Medicine (ASRM) as two or more consecutive miscarriages. Extensive research has been performed in order to determine the etiologies of recurrent loss. However, epidemiologic inconsistencies across studies and lack of power in many studies have made diagnostic and therapeutic recommendations scarce. Completing the recommended work-up for RPL, etiology is determined in approximately 50 % of couples with RPL. Most of the diagnosed etiologies include endocrine abnormalities, autoimmune disorders, uterine anomalies, and genetic factors. Still, 50 % of couples have no known etiology after a full diagnostic work-up. Therefore, a multifaceted approach is warranted to generate a general prognosis for each couple. This chapter will discuss the epidemiologic characteristics of patients with RPL including the etiologies and the impact on the prognosis.