CH(99)05

29 October 1999

Dear Colleague,

MIXED ICSI/IVF EMBRYO TRANSFERS

I am writing to you with regard to the replacement of embryos produced by ICSI together with IVF embryos in a single embryo transfer. As you are aware, there is currently an ICSI licence condition that prohibits the replacement of embryos produced using ICSI with any other embryos in the same treatment cycle, i.e. a mixed embryo transfer.

After reviewing this policy, the HFEA have concluded that, despite ongoing concerns about the effect mixed embryo transfers may have on the monitoring of ICSI practice, it may nevertheless be beneficial to some patients in exceptional circumstances. The HFEA has therefore agreed to the limited use of mixed embryo transfers, but subject to the following restrictions:

  • as in any embryo transfer, the total number of embryos transferred in any one cycle should not exceed 3;
  • in order not to compromise the monitoring and follow up of ICSI, an upper limit per centre of 2% of ICSI embryo transfers per annum should be set for mixed cycles (i.e. if a centre carries out 100 ICSI cycles over 12 months, they can carry out a maximum of 2 mixed cycles during that time period). This was based, in part, on the feedback received from centres suggesting that this procedure would only be suitable for a small number of their patients. This limit will be incorporated into the standard conditions on centres' ICSI licences. The current licence condition will be replaced with a revised condition in accordance with the policy outlined above as and when licences come before a licence committee for renewal, or for any other variation. If any centres need to effect this change ahead of their next licence renewal, they may apply specifically for this variation to be made;
  • mixed embryo transfers should only be used in exceptional circumstances. These exceptional circumstances should be clearly recorded in the patient's notes. Illustrations of situations that might be considered exceptional include:
    a)   Cases where oocytes were split into IVF and ICSI groups, but where only one viable IVF embryo and one viable ICSI embryo is available for replacement;

b)   Cases where a couple have only one or two embryos in storage resulting from each technique;

  • the procedure should only be performed by ICSI practitioners who have demonstrated technical competence (i.e. 3 months' clinical practice and a minimum of 5 pregnancies);
  • mixed cycles should be notified to the Authority, via your inspector co-ordinator, retrospectively on a monthly basis; and
  • HFEA data form (99) T.1.0 should be completed in accordance with the attached instructions.
    Please contact your centre's inspector co-ordinator if you have any queries regarding varying your licence or any aspect of this letter.

Yours faithfully,

Ruth Deech
Chairman

 

Guidance Notes
Completing the Treatment & Embryo Creation & Use Form in respect of a mixed embryo transfer

The recording of the mixed cycles in question 12 will be as follows:

Fresh mixed transfer
The IVF and ICSI components of the treatment should be recorded on separate lines. The number of fresh IVF and ICSI embryos transferred and/or stored for use by the patient is recorded individually within its own row. Discarded eggs/embryos are also recorded within their own row. The number of eggs used and embryos developed must equal the number of embryos/eggs transferred, stored and discarded.

Frozen mixed transfer
The frozen IVF and ICSI components of the treatment should be recorded on separate lines. The number of frozen IVF and ICSI embryos thawed and found viable for use by the patient is recorded individually within its own row. Discarded eggs/embryos are also recorded individually within their own row. The number of thawed /viable embryos must equal the number of embryos transferred and discarded.

N.B. All donors must be registered with the HFEA with unique donor reference numbers using form number (91) 4 for pre April 99 and (99) D for post April 99.

Page last updated: 15 August 2012