Blastocyst culture: toward single embryo transfers

Area of Science:

• Reproductive biology
• Embryology
• In vitro fertilization

Background:

• Sequential culture media support human blastocyst development by meeting changing nutrient needs.
• Blastocyst transfer on day 5 yields higher implantation rates than cleavage stage embryo transfer.

Purpose of the Study:

• To evaluate the impact of sequential culture media and blastocyst transfer on in vitro fertilization (IVF) efficiency.
• To assess the potential for reducing multiple gestations through blastocyst transfer.

Main Methods:

• Utilizing sequential culture media for human blastocyst development.
• Comparing implantation and pregnancy rates between blastocyst and cleavage stage embryo transfers.
• Developing a blastocyst scoring system to identify high-potential embryos.
• Modeling IVF efficiency based on embryo transfer and cryopreservation data.

Main Results:

• Blastocyst transfer on day 5 significantly increases implantation rates compared to day 2 or 3 transfers.
• Fewer blastocysts are needed for acceptable pregnancy rates, reducing multiple gestation incidence.
• Blastocyst transfer increases IVF efficiency by approximately 20% compared to day 3 transfers.
• A scoring system identified blastocysts with up to 70% implantation potential.

Conclusions:

• Sequential culture media and blastocyst transfer enhance IVF outcomes.
• This approach offers a viable strategy for reducing multiple pregnancies.
• The development of a single blastocyst transfer is a significant advancement for patient care.