Today, 40 years after its inception, In Vitro Fertilisation (IVF) helps close to 5% of Europeans realize their dream of becoming parents. While IVF has been a game-changer for many hopeful families, it is still a complex process for most people and can take a physical, emotional, and financial toll on both you and your support network. The more you know about IVF, the easier it will be for you and your doctor to decide if it is right for you.
The process of IVF involves stimulating a woman's ovaries to release as many eggs as possible, retrieving those eggs, inseminating those eggs and then nurturing the resulting embryos to a promising stage of development before transferring an embryo, or embryos, into the uterus in hopes of creating a successful and healthy pregnancy. Many details of your treatment plan will be tailored specifically to you and your partner once you’ve completed the preliminary tests, but in general, IVF follows a similar process.
In a person’s natural ovulation cycle, one egg is produced each month in the ovaries and travels through the fallopian tubes for possible fertilisation. In this case, becoming pregnant is completely dependent on that singular egg. With IVF, the goal is to stimulate the ovaries into producing as many healthy eggs as possible to increase your overall chances of fertilisation. This increased stimulation occurs through daily subcutaneous injections of different hormones, which means 1-4 injections into the stomach each day.
Medication, dosages, and timing of injections will vary from person to person, but typically, this phase of treatment lasts between 10 and 20 days. Clinical monitoring is performed every other day during this time. You’ll go to your clinic in the morning so that they can check the hormone levels in your blood and use ultrasound scans to monitor follicle growth. It might sound like a lot of work, but this will help your doctors make sure that your body is responding to the medication and your follicles are developing exactly as you want them to.
Once it’s been confirmed via ultrasound that most of the follicles are at least 19–21 mm in size, we’ll know that we’re nearly ready for the stimulation phase to be brought to a close. One more injection is given to induce final egg maturation, and the timing of it is quite precise. This final maturation takes about 36 hours, so your egg retrieval will typically be scheduled for 36 hours after the time of injection.
Using ultrasound guidance, the gynaecologist will puncture each follicle that has grown to the correct size and retrieve the egg from inside it. The actual retrieval procedure is a fairly quick process, typically no more than 20 minutes, and since you’ll be under general anaesthesia, you’ll be asleep and feel no discomfort. Someone will have to escort you home afterward due to the anaesthesia.
After the retrieval, the embryologist uses a microscope to inspect and identify the eggs, at this point called oocytes, that were gathered during the procedure and they get classified according to how far along they are in the maturation process. The total number of mature eggs is the amount of eggs that the embryologist can attempt to fertilise.
During this second phase you’ll need to have a sperm sample, either from your partner or a donor, and the lab will prepare the sample for fertilisation. Then the eggs and sperm are joined together so that fertilisation may take place.
There are two ways this can occur—either the sperm find their way on their own or the sperm is guided and helped through injection to find its way into the egg precisely. The first more closely mimics what happens naturally inside the body. An egg and a high quantity of viable sperm will be placed together in a petri dish, and the sperm attempt to fertilise the egg without further laboratory assistance. The second method is through ICSI, which involves the sperm getting a bit more assistance from the lab. An embryologist will pick out the “best” looking sperm and inject one live sperm directly into each egg. After attempted fertilisation, everything is then stored in an incubator at 37°C in an atmosphere with a mix of gases and humidity level that are similar to those of the human body.
If the egg is successfully fertilised by the sperm, it is then known as a zygote. The following day, the lab will check to see how many eggs fertilised to become zygotes. Then, the lab will allow them to grow for 3-5 days. Each day they are observed and tracked as they undergo cell division, becoming blastocysts. At the end of this growth and observation period, blastocysts will either be prepared for a fresh embryo transfer, or frozen for a frozen embryo transfer with your next cycle.
The embryo transfer is typically a quick and painless procedure. No anaesthesia is needed, however it is still performed in an operating room for the proximity of the reproduction laboratory where the embryos are stored.
During your transfer, viable embryos are inserted through the cervix and deposited close to the uterine fundus, which is the broad curved upper area where the fallopian tubes connect to the uterus. This is done using a special very thin catheter specifically used for embryo transfer. The number of embryos you’ll transfer depends on your age, the number of unsuccessful previous attempts, and your overall health assessment. Don’t worry, you and your doctor will make this decision together.
Over the next few days, you might also take progesterone either vaginally or subcutaneously, and in some cases you’ll be prescribed oral, vaginal, or transdermal oestrogen. Maintaining healthy levels of progesterone and oestrogen help make sure your embryo has everything it needs to develop as it needs to.
A pregnancy test is done 12 to 14 days after the transfer. With a urine-based pregnancy test, you can find out the results of the test in privacy and process its emotional implications in your own time. Another way is to have your doctor measure the HCG levels in your blood, which is a more precise indicator of pregnancy.
After the transferral process has concluded, all quality, viable embryos that have not been transferred are vitrified so they can be used in a later cycle without the need for another round of ovarian stimulation.