Shanghai First Maternity and Infant Hospital,

Recurrent pregnancy loss (RPL) is a multifactorial disorder defined by the American Society for Reproductive Medicine (ASRM) as two or more clinical miscarriages (CMs). However, US guidelines differ with European guidelines which defined recurrent miscarriage as three consecutive prior pregnancy losses (The Royal College of Obstetricians and Gynaecologists Green-Top Guideline, 2011). Thus, there is currently no uniformly agreed upon definition of RPL, the ASRM recommends that a clinical evaluation for RPL commence following two early pregnancy losses, and that a threshold of three prior pregnancy losses be utilized for epidemiologic studies (The Practice Committee of the American Society for Reproductive Medicine, 2012).

Although the overall incidence of RPL is low and estimated at 5% of women (The Practice Committee of the American Society for Reproductive Medicine, 2012), it presents a significant diagnostic and treatment challenge for both patients and clinicians. Guidelines for the evaluation of patients with RPL include evaluation of the uterine cavity and blood work to determine parental karyotypes and the presence of anti-phospholipid antibodies (APLA). In at least 50% of patients, however, an etiology for RPL is not identified (Stirrat, 1990; Stephenson, 1996; Stephenson and Kutteh, 2007; The Practice Committee of the American Society for Reproductive Medicine, 2012). The ASRM recommends expectant management as the current standard of care for patients with unexplained RPL (The Practice Committee of the American Society for Reproductive Medicine, 2012). Counseling patients with unexplained RPL to pursue expectant management presents several challenges. Patients often feel an urgency to conceive and expectant management can feel like a passive and time-consuming approach to conception. In addition, patients often carry a significant amount of guilt and grief in association with miscarriage. Attempting spontaneous conception can feel emotionally vulnerable; Despite reassurance of good prognosis, patients doubt that a subsequent pregnancy will be successful (Lachmi-Epstein et al., 2012). For all of these reasons, IVF and preimplantation genetic testing (PGT) have been investigated as a treatment strategy in RPL patients with the goals of shortening time to pregnancy, decreasing CM rates and increasing live birth (LB) rates.