Role of diagnostic intracytoplasmic sperm injection (ICSI) in the management of genetically determined zona pellucida-free oocytes during in vitro fertilization: a case report

Purpose: To report the utilization of diagnostic intracytoplasmic sperm injection (D-ICSI), an ICSI cycle performed in the natural cycle, to obtain information about embryo development potential after sperm injection into zona pellucida (ZP)-free oocytes. Materials and Methods: We report the case of a couple with primary unexplained infertility with a history of previous failed, in vitro fertilization intracytoplasmic sperm injection (IVF-ICSI) cycles characterized by the presence of ZP-free oocytes. Whole exome sequencing (WES) was carried out to analyse the possible genetic basis of oocyte abnormality. Results: Diagnostic ICSI provided information about the embryo development potential from ZP-free oocytes and allowed better planning of the subsequent ICSI cycle. WES revealed that the absence of ZP was likely to be due to a new (ZP1) mutation. The subsequent ICSI cycle resulted in the delivery of a healthy baby. Discussion: To the best of our knowledge, our report is the first to describe the use of D-ICSI to determine the feasibility of embryo development and implantation in a patient with ZP1 mutation, resulting in the subsequent delivery of a healthy baby. We used 'diagnostic' ICSI in the normal menstrual cycle to explore the feasibility of embryo development after sperm injection into ZP-free oocytes. Our results may expand the spectrum of diagnostic procedures associated with unexplained infertility.