This is normally achieved with a hormonal injection called FSH (follicle stimulating hormone). This is the hormone that usually drives the production of a follicle in the normal menstrual cycle. Sometimes some preparations are used that also contain a hormone called LH (luteinising hormone). These injections are given daily as a subcutaneous injection.

Once follicles reach a certain size in the menstrual cycle (usually around 17mm or above) then a surge of LH hormone will normally occur allowing the release of an egg to take place. For IVF treatment eggs needs to be collected so it is necessary to control this process either by stopping the release of LH. This is achieved either by a drug called Cetrotide or Fyremadel.

As the ovaries are being stimulated with FSH injections the response to this medication is being measured by ultrasound scans and blood tests. Once there are sufficient follicles of large enough size a trigger injection is given. A trigger injection for egg collection is a hormone shot that mimics the body's natural surge, prompting the final maturation of the eggs and preparing them to be released from the follicles in the ovaries. The injection is given at a precise time, usually about 36-40 hours before the scheduled egg retrieval, to ensure the eggs are fully mature and ready for collection before they ovulate naturally.

Egg collection is done transvaginally in much the same way as a transvaginal scan. The procedure normally takes up to 30 minutes. Egg collection typically uses moderate conscious sedation, administered by an anaesthetist, which involves a painkiller and a sedative. This allows for a quick recovery where you can eat and drink before going home. If you have had any form of sedation, your ability to make decisions may be impaired and although you may feel very well in yourself, you should not drive or make any important decisions.

You also need to have someone with you for 24 hours after any anaesthetic procedure to look after you in case you have any reaction to the anaesthetic, or drop in your blood pressure and feel faint. This can be your partner, relative or friend and they should contact the clinic if they have any concerns or worries.

You will have previously discussed with the team how any eggs collected may be fertilised. A sperm sample is produced on the same day as egg collection or thawed from a frozen sample. The sperm sample is then prepared with the goal is to select high-quality, progressively moving sperm for fertilization, improving the chances of a successful pregnancy by removing less viable sperm.

There are different ways and further preparation techniques involved in achieving fertilisation in the laboratory:

• Conventional IVF - Many sperm (50,000 to over 100,000) are added to each dish with a single egg, allowing one sperm to fertilize the egg naturally, mimicking natural conception.

• ICSI (intracytoplasmic sperm injection) - A single, healthy sperm is selected and injected directly into the center of the egg. This can be used when:

  • The count, motility and morphology of the sperm are not judged as being sufficient for normal fertilisation to occur.

  • There has been previous poor or non-fertilisation with IVF treatment.

  • In some specific assisted conception techniques such as PGT-M

  • Previously frozen eggs are being used.

• IMSI (Intracytoplasmic morphologically selected sperm injection) is a sperm selection method used in intracytoplasmic sperm injection (ICSI). The technique involves using a microscope to view detailed images of the sperm under very high magnification (over x6000) to select the sperm to inject into an egg.

  • This can be used by the embryology team should it be diffcult to find top quality sperm under the ICSI magnification.

  • While we are able to perform IMSI at our partner labotatories, this add-on is not something we routinely recommend to patients.

• Sperm ZyMot - A filtering device for sperm. The embryology team injects semen into the inlet port in the ZyMot device. The healthy, motile sperm will swim up and through an internal membrane filter, where it can then be collected and used for treatment. The poorer quality sperm get left behind as they are unable to cross the membrane barrier. This can be used when:

  • The embryology team is looking for a better way to process sperm by separating the the healthy and unhealthy sperm.

  • A previous ZyMot diagnostic test has indicated that it will reduce the levels of DNA fragmentation in the sample.

The morning after egg collection we will know how many of the eggs have been fertilised. The embryos are observed for the following 7 days. This will depend upon how many eggs have fertilised and how the embryos have developed.

The embryos are incubating in a time-lapse imaging system. Time-lapse incubation and imaging allow the embryologist to take thousands of images of the embryos as they grow without disturbing them. Not only does this mean the embryos do not have to be removed from the incubator, it also allows the embryologist to get a continuous view of each embryo as it develops, rather than just viewing them once a day.

The embryos that reach blastocyst will be graded based on how they appear when checked, usually by looking at the number and appearance of cells.

• The number of embryos to be transferred will already have been discussed before the day of embryo transfer. We suggest that a single embryo is transferred especially if:

• The patient is young (<37 years)

• The patient has good quality embryos

• The patient has had previous multiple pregnancies

• If PGT-A tested, we only transfer one euploid embryo

• We advise patients to have a half to full bladder for your embryo transfer this will enable a smooth transfer of your embryos. The bladder when full pushes down on the uterus allowing easier access into the uterine cavity and allows us to place the embryo in an optimal position.

Generally, embryo transfer is done without sedation although if there have been difficult transfers in the past or a need for sedation this can be arranged.

Following a fresh transfer, if we have additional embryos of sufficient quality then these will be frozen.

Many of LCRH’s patients will also chose to have elective freeze all cycles. This means that the intention for the cycle is to conclude with frozen embryos and not with an embryo transfer. This can be when:

• Patients are testing their embryos via PGT-A / PGT-M (the biopsied embryos are subsequently frozen).

• It is medically indicated due to hormonal response in the egg collection cycle such as OHSS risk and high progesterone.

• Family planning around embryo transfer timings.

These frozen embryos can then be thawed and transferred at a later date via a Frozen Embryo Transfer (FET) cycle.