What happens during IVF treatment?

IVF treatment is often referred to as an IVF cycle. An IVF cycle consists of four basic steps; the phase of ovarian stimulation, the egg retrieval procedure, the fertilisation of the eggs with sperm in the embryology laboratory and finally the embryo replacement inside the womb.


What is the phase of ovarian stimulation?

During a natural, menstrual cycle, a single follicle gradually develops and is released. This single follicle contains a single egg. It is possible to have IVF treatment using this single egg from a natural cycle, but the success rates with this method are lower in comparison with IVF cycles using ovarian stimulation. Hence, the majority of IVF cycles involve stimulation of the ovaries with medication known as gonadotrophins.

These drugs aim to produce multiple eggs simultaneously. The medication is given as self-administered subcutaneous injections, which are used once every day for approximately 12 days. During this time, the ovarian stimulation is monitored closely by regular ultrasound scans and sometimes by performing a hormonal, blood test. By interpreting the results of ultrasound and blood tests, the specialist will determine the best time to perform the egg collection.

Approximately thirty-six hours before the egg collection is due, an injection of a hormone called human chorionic gonadotrophin (hCG) is administered. This drug aims to complete the final process of egg maturation. Accurate timing is essential as the eggs will be ready for retrieval around thirty-four to thirty-six hours after the hCG injection. The exact timing of the hCG injection and the egg retrieval will be individualised to allow for the optimal outcome with regards to the egg quality and quantity.

All women having treatment with Ark IVF are offered direct, one-to-one care with Dr Christopoulos, who will perform all the ultrasound scans and individualise your dosing regimen throughout. You will be monitored closely on a daily basis to allow for the optimal response to the medication.


Is the phase of ovarian stimulation the same for everyone?

This is not the case. An essential component of a successful IVF cycle is an individualised ovarian stimulation. No two people respond in the same manner to the use of this medication. Consequently, it is important to tailor the ovarian stimulation to the individual women and not the woman to the ovarian stimulation. The dose of the medication will depend on the woman’ age, the body weight, the cause of subfertility and the previous history of any IVF treatment.


What happens during the egg retrieval procedure?

This procedure is performed under sedation using a vaginal ultrasound probe. A specially-designed, fine needle is attached to the ultrasound probe. The needle is guided through the top of the vagina and into the ovary. The fluid is then drawn out of each ovarian follicle using a special, suction device. This fluid is examined under the microscope immediately after the retrieval so that we can precisely identify the exact number of eggs collected. The procedure usually lasts abouttwenty minutes. At the end of the procedure, the woman is allowed one to two hours to recover from the sedative effect of the medication and is then allowed to go home.



The egg retrieval will be personally performed by Dr Christopoulos. A Consultant Anaesthetist will be present to administer the sedative medication and closely monitor the depth of sedation. To allow for a true, personalised approach, the egg retrieval process can be performed on any day, the unit is open seven days a week and the timing of the procedure is based on the individual ovarian response.



IVF: How does fertilisation take place in the embryology lab?

The embryologist identifies the eggs in the laboratory and carefully places them in a liquid known as the culture medium. The eggs are then placed on dishes inside an incubator. The male partner-if applicable- produces a semen sample by masturbation and this is prepared in the laboratory. In other cases, there is an option to select sperm from an anonymous, sperm bank. The sperm undergoes a specialised process of preparation, during which the best, most motile and active sperm is selected. The best of these active sperm are then placed together with the eggs to inseminate them.

If the male partner has been diagnosed with a significant reduction in sperm concentration or motility, then a process called ICSI (intra-cytoplasmic sperm injection) is likely to be advised. During the ICSI procedure, a single sperm is selected by the embryologist and injected directly into the egg.

After about eighteen hours, fertilisation is usually completed and after a further twelve hours the embryo (fertilised egg) begins to divide. Two to three days after the egg collection, the embryos have usually divided into four to eight cells. They subsequently continue grow in the laboratory and by day 5 they continue to grow and form a blastocyst. This is a more advanced stage of embryo development, in which the embryo shows a distinctive ‘inner cell mass’ (which forms the baby) and a separate outer layer of cells, which form the placenta. The embryos are monitored under carefully regulated conditions of temperature, pH, O2 and CO2 concentrations. The embryos are then scored against a specific grading system, which allows us to select the best possible embryo(s) for the transfer inside the womb.

The embryology team consists of a concise group of highly skilled and selected scientists with extensive experience in the culture of gametes. Our team have a robust quality management system, which ensures that eggs, sperm and embryos are cultured in the best conditions possible.


IVF: How is the embryo transfer performed?

Embryos are transferred either at three days after egg collection, or when they have reached the blastocyst stage (please see above). The Consultant together with the embryologist will advise which is most appropriate in your case, depending on the number of embryos that develop and their quality.

The embryo transfer constitutes the pinnacle moment of the whole treatment. It is performed under ultrasound guidance and is virtually painless and does not require any sedation. One embryo is usually transferred unless there are specific reasons to think that it may be necessary to transfer two. As there is no evidence that bed rest makes a difference to the outcome, our advice to women is to resume their normal activities straight after the embryo transfer.

All embryo transfers are performed by Dr Christopoulos, who has unparalleled experience in this procedure, having performed thousands of transfers in the UK and in Greece with very high success rates.


What happens after the embryo transfer?

The time interval between the embryo transfer lasts 12-14 days and is known as the luteal phase. During this time, the transferred embryo(s) will try to implant inside the lining of the womb (the endometrium).  To aid the process of implantation, hormone supplementation in the form of progesterone pessaries, vaginal gel or subcutaneous injections are usually prescribed.

Unlike most clinics, it is our practice to individualise the luteal phase hormonal support by carefully monitoring your hormonal blood levels on a regular basis. This means that your luteal phase support –similarly to your ovarian stimulation- will be tailored to your body’s needs with precision to promote the embryo implantation. This supplementation will often continue for the first few weeks of the pregnancy under precise guidance.


Embryo freezing

With an aim to increase your cumulative pregnancy rate, our team will offer embryo freezing and storage for any surplus, good-quality embryos. We use the best, available method of freezing called vitrification, which allows for ultra-rapid freezing of the embryos with outstanding embryo survival rates. However, not all surplus embryos are suitable for freezing as some may not survive the procedure. In our hands, we have demonstrated similar (and in some times better) pregnancy outcomes with the use of frozen-thawed embryos.