In Vitro Fertilisation. A process by which an embryo is created outside the body in the laboratory. The eggs, that are collected during a straightforward operative procedure, and the prepared sperm are mixed together in a culture dish, kept together over night before being assessed for signs of fertilisation.

In-vitro fertilisation, which is most commonly known and referred to as IVF, is one of the most popular and regularly used treatments for those who need help conceiving. The most basic explanation of its process is that it involves removing eggs from a patient and mixing these with a partner’s or donor’s sperm in order to create embryos. These embryos are then placed inside the intended parent’s womb in the hopes that they will carry a successful pregnancy to term.

“In-vitro” comes from the Latin term for “in glass”, referring to the glass test tubes that were used in early IVF procedures. Since these first procedures, beginning with the conception and birth of Louise Brown in 1978, the practice has only grown further, allowing for technology to develop and making treatments that allow for conception outside of the body to take place on a regular basis.

According to the Bristol Centre for Reproductive Medicine, approximately 2% of children born in the UK today are conceived through IVF treatments and technology.

Types of IVF Treatment

There is more than one type of IVF available in the UK, and the one used for any particular patient will all depend on their circumstances.

Stimulated or Conventional IVF

Stimulated IVF, which may also be called Conventional IVF, works by using specific drugs to obtain multiple eggs from a patient. These eggs are then mixed with sperm to create multiple embryos, some of which will be frozen and stored for future use. This allows the patient to try again if the first cycle is not successful, or if they would like their first child to have a sibling later on.

Mild IVF

This form of treatment works in a similar manner to Stimulated IVF, and may also be called Mild Stimulated IVF for this reason. In this treatment form, stimulating drugs will be used to collect between 2 and 10 eggs for the fertilisation process. These drugs will be given at a lower dosage and for a shorter duration period than that of Stimulated IVF, however.

Natural Cycle IVF

Natural IVF differs from both Mild and Stimulated IVF in that it does not use drugs or medication to stimulate egg production through follicle growth. Instead, it relies on the patient’s natural menstrual cycle to select the best follicle, which will then produce the best egg available for the cycle. When this egg is mature (on around the 10th to 12th day of their cycle), it will be collected by a specialist.

The IVF Process

Every possible step in the IVF treatment process is outlined below. This includes the steps that will only be carried out if a patient is undergoing Mild or Stimulated IVF:

  1. Ovarian stimulation, in which a patient is given hormone injections to stimulate their ovaries into recruiting a large number of follicles and increasing the chances of retrieving eggs from them
  2. The trigger injection, in which a final injection of human chorionic gonadotropin (hCG) or gonadotropin releasing hormone agonist (GnRHa), will be given after approximately 9 to 14 days of stimulation. This should take place between 35 and 36 hours before egg collection
  3. Egg collection, in which eggs are retrieved under mild sedation anaesthesia using a vaginal ultrasound probe to aspirate the follicles
  4. Mixing the eggs and sperm, in which egg cells will be introduced to sperm cells provided by a patient’s partner or a donor. The morning after this happens, an embryologist will monitor the mix for signs of fertilisation
  5. Embryo transfer, which should take place 3 to 5 days after an embryo has been declared viable. In this step, the embryo will be transferred to the uterus of the intended parent using a catheter and released into the middle of the cavity of the womb
  6. A blood pregnancy test, which should take place 14 days after the embryo transfer. This will give the most reliable indication of whether or not the cycle has been successful

If there are any unused, good quality embryos left over from the fertilisation step, they can be frozen for future use.