Single embryo transfer in IVF to prevent multiple pregnancies.

Area of Science:

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

Background:

• Improving IVF success rates has led to an increased incidence of twin pregnancies, primarily due to the number of embryos transferred.
• Even with a two-embryo transfer policy, twinning rates can exceed 40% of pregnancies, posing risks to both mother and child.
• Effective cryopreservation of surplus embryos is crucial for single embryo transfer (SET) to maintain pregnancy success rates.

Purpose of the Study:

• To evaluate the efficacy of single embryo transfer (SET) compared to double embryo transfer (DET) in IVF.
• To determine if SET can achieve comparable cumulative pregnancy rates to DET while reducing the high rate of twin pregnancies.
• To assess the impact of improved cryopreservation techniques on the viability of SET programs.

Main Methods:

• Analysis of clinical data from a multi-year IVF program.
• Comparison of pregnancy and cumulative pregnancy rates between SET and DET groups.
• Evaluation of cryopreservation success rates for supernumerary embryos.

Main Results:

• The study observed increasing IVF success rates and a corresponding rise in twinning rates.
• Improved cryopreservation outcomes facilitated the implementation and trial of a SET program.
• Clinical data demonstrated that SET achieved comparable cumulative pregnancy rates to DET.

Conclusions:

• Single embryo transfer is a clinically superior option for reducing twin pregnancy rates in IVF.
• SET, supported by effective cryopreservation, offers a viable strategy to improve IVF safety without compromising overall success.
• The findings strongly support the adoption of SET as a standard practice to mitigate the adverse consequences of multiple gestations in assisted reproductive technology.