Application of late rescue ICSI in protocols after complete absence of standard IVF fertilization

Background. According literature data total fertilization failure (TFF) in cycles with conventional insemination occurs in 2.3—3.5% of all programs. After the TFF a rescue intracytoplasmic sperm injection (Re-ICSI) is carried out. There is no consensus on the use of Re-ICSI. Objective. Analyze the received data on Re-ICSI. Determine the tactics of managing patients after TFF. Material and methods. A retrospective data analysis was performed at the AVA Peter Clinic from 2009 to the June 2023. The patients were divided into two groups: the first group was under 35 years old, the second was 35 years and older. Results. TFF in the first group was 1.9%, versus the second group 3.9%. 30.9% embryos used for transfer and cryopreservation after Re-ICSI. In the first group was 72.9%, versus second group 46.9% (p<0.05). Pregnancy rate per Re-ICSI cycles for the first and second groups to 27.12% and 8.16% respectively (p<0.05). In total, from the 108 Re-ICSI cycles performed 16 (18.5%) live births have been achieved. For the first and second groups to 18.6% and 6.1% respectively (p<0.05). Pregnancy rate per frozen embryo transfer 37.5% versus fresh embryo transfer 24% (p<0.05) Conclusion. Re-ICSI may be recommended for TFF. Re-ICSI with frozen compared fresh embryo transfer gives better results. The low efficiency of the Re-ICSI for patients 35 years and older.