Artificial shrinkage before fresh blastocyst transfer and IVF outcomes: a pilot randomized controlled study

Area of Science:

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

Background:

• Fresh blastocyst transfer is a common IVF procedure.
• Optimizing blastocyst quality and transfer success is crucial for improving IVF outcomes.
• Investigating novel techniques like artificial shrinkage aims to enhance implantation and pregnancy rates.

Purpose of the Study:

• To evaluate the efficacy of artificial shrinkage (AS) applied to blastocysts before fresh single-blastocyst transfer in improving clinical pregnancy rates.
• To assess the impact of AS on multiple pregnancy and live birth rates.
• To explore the relationship between cell-free DNA (cfDNA) concentration and IVF outcomes.

Main Methods:

• A monocentric, prospective, randomized, double-blind, controlled pilot study involving 150 couples undergoing fresh single-blastocyst transfer.
• Participants were randomized into an artificial shrinkage (AS) group (laser pulse to trophectoderm) or a control group (no AS).
• Clinical outcomes (pregnancy, multiple pregnancy, live birth) and cfDNA concentration in culture medium were analyzed using intention-to-treat and per-protocol analyses.

Main Results:

• The clinical pregnancy rate was comparable between the AS group (49.5%) and the control group (48.9%) in the intention-to-treat analysis.
• Per-protocol analysis also showed similar clinical pregnancy rates (AS: 51.1% vs. Control: 48.94%).
• No significant differences were observed in multiple pregnancy rates, live birth rates, gestational age, birthweight, or newborn sex ratio between the groups. cfDNA concentration was not associated with IVF outcomes.

Conclusions:

• Artificial shrinkage applied to blastocysts before fresh single-blastocyst transfer did not demonstrate a significant improvement in clinical pregnancy rates in this pilot study.
• The technique did not influence other key IVF outcomes such as multiple pregnancy or live birth rates.
• Larger-scale randomized controlled trials are necessary to validate these preliminary findings and definitively assess the role of artificial shrinkage in IVF.