Your essential guide to In Vitro Fertilisation (IVF)

IVF (In Vitro Fertilisation) helps many hopeful families realise their dreams every day. But there are no guarantees. And whether they’re physical, emotional or financial, there can be challenges that go along with IVF too. So the more you know now, the better placed you’ll be to decide – with your doctor – whether IVF is the right choice to make for your best chance.

How the IVF process works

Your IVF treatment plan will have some personalised aspects to it. These will be tailored to you (and potentially your partner) by your care team once your preliminary tests are done. Generally speaking though, every IVF plan follows a similar process.

The woman’s ovaries are stimulated to release as many eggs as is safely possible. Those eggs are retrieved so they can be inseminated. Then the resulting embryos are nurtured to a promising stage. Finally the embryo (or embryos) is transferred into the uterus – where a healthy and successful pregnancy is hopefully created.

Here’s how each of those stages work:

1. The ovaries are stimulated

In a natural ovulation cycle, one egg is produced each month in the ovaries and travels through the fallopian tubes for possible fertilisation. So becoming pregnant is completely dependent on that one, singular egg.

But with IVF, the goal is to stimulate the ovaries into producing as many healthy eggs as possible. That way your overall chances of fertilisation increase. This increased stimulation happens through daily subcutaneous (ie, under the skin) injections of different hormones given 1-4 times daily.

This part of the process usually lasts 8-20 days – with clinical monitoring every other day. The duration, dosage and medications vary from person to person because your care team wants to make sure this process is as controlled as possible. You’ll go to your clinic in the morning. The hormone levels in your blood will be checked. And ultrasound scans taken to monitor follicle growth.

It might sound like a lot, but it all helps your doctors make sure your body is responding to the medication and your follicles are developing exactly as you want them to.

Once an ultrasound has confirmed that most of your follicles are at least 19–21 mm in size, we’ll know we’re nearly ready to move on to the next step.

2. The eggs are retrieved

Once the follicles have reached the ideal size, an HCG injection (short for Human Chorionic Gonadotropin) triggers the final stage of maturation and ovulation. The timing of this trigger shot is quite precise. This final maturation takes about 36 hours, so your egg retrieval will typically be scheduled for 36 hours after that 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 fairly quick – usually no more than 20 minutes. And since you’ll be under general anesthesia, you’ll be asleep and feel no discomfort. Although for that same reason someone will have to be there to escort you home.

3. The eggs are nurtured and fertilised

After the retrieval, the embryologist uses a microscope to examine the eggs (at this point they’re now called oocytes) gathered during the procedure. They’ll be classified according to how far along they are in the maturation process. And 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 – 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 happen. 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.

The first option (IVF) 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 called ICSI. This 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 stored in an incubator at 37°C in an atmosphere with a mix of gases and humidity-level similar to 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, becoming zygotes. Then, the lab will let them 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 an embryo transfer in the future.

4. The embryo is transferred to the uterus

The embryo transfer is typically quick and painless – no anaesthesia is needed. During your transfer, the viable embryo, or 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 helps make sure your embryo has everything to develop as it needs to.

A pregnancy test is done 12 to 14 days after the transfer. This is typically an ultrasound scan in the clinic. Another way is to have your doctor measure the HCG levels in your blood, which is a more precise indicator of pregnancy.

5. Viable, left over fertilized eggs are frozen and saved

After the transferral process has finished, all the quality, viable fertilized eggs that have not been transferred are frozen, sometimes referred to as vitrification. That way they can be used in a later cycle without the need for another round of ovarian stimulation.

Deciding whether or not to go through IVF is a big decision. Now that you know more about it we encourage you to keep on learning and asking questions.