Conditional and cumulative live birth rates after blastocyst transfer

Area of Science:

• Reproductive Medicine
• In Vitro Fertilization (IVF)
• Embryology

Background:

• The live birth rate (LBR) and cumulative live birth rate (CLBR) are key indicators of in vitro fertilization (IVF) success.
• Optimizing IVF protocols, including embryo selection and transfer strategy, is crucial for improving patient outcomes.
• Previous studies often focused on cleavage stage transfers, necessitating research into blastocyst-only strategies.

Purpose of the Study:

• To evaluate the live birth rate (LBR) and cumulative live birth rate (CLBR) for consecutive fresh and frozen-thawed IVF cycles.
• To determine the CLBR after an entire IVF program utilizing exclusively blastocyst transfers.
• To compare the efficacy of blastocyst transfer with previous findings using cleavage stage transfers.

Main Methods:

• A retrospective analysis of 871 women undergoing IVF/intracytoplasmic sperm injection (ICSI) from 2014-2018.
• Inclusion criteria: women aged 18-45 years initiating IVF cycles.
• Primary outcome: live birth; secondary outcomes: positive hCG, ultrasonographically confirmed ongoing pregnancy. Proportions calculated for initiated and transferred cycles.

Main Results:

• The LBR for first fresh cycles was 22.8% (initiated) and 35.7% (transferred).
• The LBR for first frozen-thawed cycles was 30.6% (initiated) and 31.7% (transferred).
• For women completing an entire IVF program (n=436), the CLBR using only blastocyst transfer was 64.0% (95% CI: 59.3-68.5).

Conclusions:

• Blastocyst transfer exclusively demonstrates a considerable positive effect on IVF success rates compared to cleavage stage transfers.
• The findings suggest that a strategy of exclusively transferring blastocysts is a viable and effective method in clinical IVF practice.
• This approach offers a promising avenue for enhancing cumulative live birth rates in fertility treatments.