Masters Thesis

Embryo transfer based on preimplantation genetic testing: a critical assessment of current practice and policy guidelines

Purpose: To investigate the status of policies and practices of in vitro fertilization (IVF) clinics regarding transfer of embryos with positive, abnormal, or mosaic results following preimplantation genetic testing for aneuploidy and for monogenic disorders (PGT-A and PGT-M). Methods: An online survey was emailed to 394 IVF clinics across the United States. In-depth interviews were conducted with a subset of 11 survey respondents. Results: A total of 97 clinics completed a survey (25% valid response rate). 37% of clinics had written policies on transferring embryos with positive or abnormal results which they discuss with patients before testing and 54% handled patient requests on an individualized case-by-case basis. A minority of clinics reported having previously transferred one or more embryos with a non-mosaic non-viable aneuploidy (12%), partial aneuploidy (12%), or viable aneuploidy (7%). No clinics have transferred embryos positive for a monogenic childhood-onset life-limiting disorder. However, 16% of all clinics have transferred embryos positive for reduced penetrance, variable-onset monogenic disorders, and most clinics (69%) would consider transferring such embryos. Interview responses suggested that clinic policies are shaped by previous or anticipated patient requests and desire for either standardized or discretionary practice. Factors contributing to provider considerations for transfer of positive or abnormal embryos included individual patient circumstances, variability of clinical outcomes, liability and financial concerns, and ethical considerations. Conclusions: Ongoing discussion of establishing practice guidelines is critical as PGT-A results become increasingly complex, the scope of indications for PGT-M use expands, and providers increasingly encounter these requests from patients.