Single Embryo Transfer (eSET)

For several years the HFEA have been asking IVF clinics to reduce their rates of multiple pregnancy – for reasons of safety for the mother and baby. They have been setting annual targets for clinics to achieve reductions in the proportions of multiple pregnancy. For 2013, the target is set at 10% of all pregnancies. This can only be achieved by a reduction in the number of ‘two embryo transfers’ that are carried out.

When considering elective single embryo transfer (eSET), CRGW has instigated policies which in combination with advances in the laboratory, seek to ensure that the overall clinical pregnancy rates and chances of success of these patients are not reduced.

Policies and laboratory techniques employed by CRGW to ensure the best possible chance of pregnancy with single embryo transfer include:

  • A successful vitrification (embryo freezing) protocol ensuring the best chance of pregnancy should frozen embryo transfer be required
  • EmbryoScope time-lapse imaging: Ensures single embryos with the highest likelihood of implantation are selected

It is clear that the policies put in place, in combination with the highly successful vitrification programme for embryo freezing, will lead to the reduction in multiple births, and increased clinical pregnancy rates.

Evidence shows that if 100 women who meet eSET criteria were split into 2 groups where 50 of the women had single embryo transfer as per recommendation and the other 50 women had double embryo transfer (DET) against recommendation, there would be more healthy babies born from the women having eSET. This is because of the increased miscarriage rate in the DET group along with decreased birth defects in the women having eSET (such things as cerebral palsy).

The team at CRGW will ensure you are properly informed of the potential benefits of single embryo transfer and the potential risks of DET. Should you elect to have two embryos transferred when you are recommended by the team to have single embryo transfer and the transferring clinician is is supportive of the clinical reasons you will be requested to sign a ‘Single Embryo Transfer Waiver’. This form lists all of the potential risks of a multiple pregnancy to mother and babies and will ensure you have fully received informed consent. You will then be required to sign this form acknowledging that you have been informed of these risks but still elect to have two embryos transferred.