Abstract:

Conventional in vitro fertilization (c-IVF) is one of the most widely used assisted reproductive technologies in clinical practice. However, 5% to 15% of total fertilization failure (TFF) rate remains a non-negligible clinical challenge, which can significantly reduce the cumulative live birth rate, directly lead to cycle cancellation and embryo resource depletion, and impose a heavy burden on patients. The short-term insemination combined with early rescue intracytoplasmic sperm injection (E-RICSI) is the core strategy for preventing TFF in c-IVF cycles. By the co-incubating sperm and oocytes for 3 to 6 hours combined with monitoring of second polar body extrusion, this technique enables a timely intervention for fertilization disorders, avoids the risk of oocyte aging in vitro, and simultaneously preserves the advantages of natural fertilization. Evidence-based studies have confirmed that this technique can reduce the TFF rate to below 1%, maintain favorable normal fertilization rate and high-quality blastocyst formation rate. Its clinical pregnancy outcomes, cumulative live birth outcomes and neonatal safety are comparable to those of conventional intracytoplasmic sperm injection (ICSI), with good health economic benefits. Nevertheless, this technique still faces some problems such as inconsistent indications, insufficient accuracy of risk stratification, and non-standard clinical application. This article reviews the evidence-based progress, risk stratification system, and clinical decision-making pathway of this technique, aiming to provide evidence-based references for its standardized and precise clinical application.

Key words: Fertilization in vitro, Sperm injections, intracytoplasmic, Risk evaluation and mitigation, Short-term insemination, Early rescue intracytoplasmic sperm injection