Frozen Embryo Replacement Cycle (FER)

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This procedure uses previously frozen embryos for treatments.  Before commencing the first frozen cycle, all patients attend an FET clinic appointment to discuss use of their embryos with a clinician or an embryologist.

Spare good quality embryos from your IVF treatment, that would otherwise be disposed of, are cryopreserved (frozen) and stored for future use. This allows a couple to have multiple embryo transfers from the same egg collection.

Frozen embryo replacements are usually managed in a hormone-medicated cycle. We do not advise treatment in a natural cycle, as we are only able to do the transfers during the week and there is a risk your transfer may be cancelled if it falls over the weekend in a natural cycle. The pregnancy rate is the same between stimulated and natural cycle frozen embryo transfer.

After starting the hormone tablets, Ultrasound scans are used to ensure that the endometrium (lining of the womb) is suitably thickened and suitable for embryo transfer.

The timing of the transfer is important and so determines when the embryos are thawed.  Our Embryology team will inform you how well your embryos have survived the thawing process and if they are of good enough quality for your transfer to take place.  Sometimes embryos do not survive the thawing process.  If this happens, we will book a review appointment for you with one of our specialists to discuss your options going forward.

The embryo transfer procedure is similar to a smear test.  It may cause some minimal discomfort.  The culture medium containing one or two embryos is loaded into a thin catheter with a syringe on the end. The doctor carefully guides the catheter through the vagina and cervix, and deposits the embryo(s) into the uterus.  Implantation begins three to four days later.

After the embryo transfer, progesterone pessaries, which contain the hormone progesterone, will be prescribed.  These are vaginal pessaries which help to support the lining of the womb.  You will be given specific instructions on how to use these by the nurses.