In vitro fertilisation (IVF) means fertilisation outside of the human body. During IVF, hormones are used to stimulate egg growth. The eggs are removed from the ovaries and fertilised with a sperm sample in a laboratory. The fertilised egg, an embryo, is transferred to the uterus in order to develop and grow into a baby. This treatment is now used effectively to treat a range of fertility-related conditions. 

When is IVF suitable? 

IVF can be a recommended treatment option for those who have had difficulty when trying to conceive through having intercourse, for those with a known infertility diagnosis or for those who have tried to conceive through intercourse for 2 years where no diagnosis has been established.

What happens during IVF?

The IVF process consists of many steps:

Consultation and consents

A first step within your fertility clinic is to have a medical consultation with a fertility specialist. They will review the results of your fertility investigations and order more tests if necessary. The results of your investigations will help create a plan for treatment and determine the best hormone stimulation protocol for you. You will also be required to sign consents for your treatment. This is an important step, as the consents are there to protect you, your sperm, your eggs and the embryos created from them. You will have a lot of paperwork from the clinic and be sure to ask your doctor or nurse if there is anything that doesn’t make sense. 

Hormone stimulation and monitoring

The hormone stimulation involves daily injections of hormones. The hormones encourage your ovaries to produce multiple eggs. You will need ultrasound monitoring during this time to ensure that your ovaries are responding well to the medication. It’s possible to have blood tests as well. The dosage of the medication might change based on how your ovaries are responding. Once the follicles in your ovaries have reached an appropriate size, you’ll be given a trigger injection (the final injection to help the eggs mature) and your egg collection will be scheduled. 

Egg collection

The egg collection takes place under sedation and you will need to be fasting in advance of the procedure. Your clinic will inform you of when to stop eating, what medications to take and when to arrive at the clinic. The eggs are aspirated from the follicles in your ovaries using a long needle and transvaginal ultrasound. The fluid from the follicles is collected in test tubes that are passed to the embryologist in the laboratory, who will notify the doctor when eggs have been found under a microscope. Your doctor or embryologist will inform you how many eggs have been collected once you’ve woken up after your procedure. It is recommended to take the day off from work and give yourself some recovery time. Your nurse should let you know what medication to be taking for pain relief if you need it and explain when to take your progesterone, which you might be prescribed to prepare the lining in your uterus for an embryo transfer.


A fresh sperm sample can be produced or a frozen sperm sample could be thawed and used for treatment. The eggs are fertilised with the sperm sample either with IVF, where sperm are allowed to swim and attempt to fertilise the eggs, or with intracytoplasmic sperm injection (ICSI), where sperm are injected individually into any mature eggs.

Embryo culture

The fertilised eggs, called embryos, are cultured in heated incubators in the laboratory and their development is monitored by embryologists. The number of developing embryos and quality will help determine a suitable day for embryo transfer. This could take place on day 2 of development (2 days after your egg collection), day 3 (3 days after your egg collection) or day 5 (5 days after your egg collection). When your embryos reach day 5, they may be referred to as blastocysts. 

Embryo transfer

Your fertility clinic will schedule you in for your embryo transfer and give you any relevant information you need to know to prepare. This will most commonly involve you drinking extra fluids on the day, in order to have a full bladder. Having a full bladder helps the doctor gain easier access to your uterus. Once you’re in position, the embryologist will load your embryo into a thin, soft catheter in the laboratory and pass it to the doctor who will place it through your cervix. The doctor may sometimes use abdominal ultrasound as guidance as the embryo gets inserted into your uterus. The catheter is passed back to the embryologist who will verify that the catheter is empty. After the transfer procedure is completed, you will be instructed when to take a pregnancy test. Some clinics will recommend taking a urine pregnancy test at home, and others may ask you to come into the clinic and have a blood test taken. 

Embryo freezing

When an embryo transfer has taken place, in some cases there will be surplus good quality embryos that could be suitable for freezing. Your embryologist or doctor should discuss the quality of the embryos and explain any additional costs you may incur for the freezing and storage of the embryos.  

Are there any risks with IVF? 

Risks with IVF include side effects from the hormone stimulation medication, like headaches, nausea, hot flushes and ovarian hyperstimulation syndrome (OHSS). OHSS, while rare, is a serious complication in IVF. It can develop when too many follicles grow during the hormone stimulation and can cause bloating, swelling and fluid retention in nearby organs if not treated. Other risks include:

  • Not responding to the hormone stimulation medication, which may lead to a cancelled cycle
  • No eggs collected during your egg collection procedure
  • No eggs fertilised after IVF or ICSI
  • No embryos available for transfer

While the above risks are small, it’s important to know that they exist and the doctor at your clinic should explain what the chances may be for you during your treatment. 

What are my chances of getting pregnant with IVF?

The chances of success of IVF can depend on your age, any known cause of infertility, previous pregnancy history and certain lifestyle factors. As many factors are involved, it’s best to speak to your doctor about your individual chances of success before starting any treatment. The most recent data from the HFEA shows that the average birth rate is 24% following IVF treatment