Multiple attempts at embryo transfer: does this affect in-vitro fertilization treatment outcome?

Area of Science:

• Reproductive Medicine
• In-Vitro Fertilization (IVF)
• Embryo Transfer Technology

Background:

• Embryo transfer is a critical step in IVF, with potential for embryo retention.
• Factors influencing embryo retention and its impact on pregnancy outcomes require investigation.

Purpose of the Study:

• To identify factors contributing to embryo transfer failure at the first attempt.
• To evaluate the effect of immediate retransfer of retained embryos on IVF treatment success.

Main Methods:

• Retrospective analysis of 1204 embryo transfer procedures from 877 patients undergoing IVF.
• Data collected between January 1991 and December 1995 at Midland Fertility Services, UK.
• Statistical analysis to determine factors associated with embryo retention and pregnancy rates.

Main Results:

• Embryo retention was significantly higher with catheter contamination (mucus or blood) and difficult transfer procedures.
• No significant difference in clinical pregnancy rates between single and multiple transfer attempts.
• No difference in embryo retention based on embryo transfer catheter type.

Conclusions:

• Aspiration of cervical mucus is recommended to reduce embryo retention.
• Immediate retransfer of retained embryos is feasible, convenient, and does not compromise IVF outcomes.
• Embryo retention, when managed by immediate retransfer, does not appear to negatively impact pregnancy rates.