IVF Treatment Process Step by Step: What Happens During an IVF Cycle?

Starting IVF can feel overwhelming because there are several appointments, medicines, scans, laboratory stages, and decisions involved. Understanding the IVF treatment process step by step can make the journey easier to follow.

In simple terms, in vitro fertilisation (IVF) involves stimulating the ovaries to produce eggs, collecting those eggs, fertilising them with sperm in a laboratory, allowing the resulting embryos to develop, and transferring a suitable embryo into the uterus. However, IVF is not exactly the same for every patient.

Your treatment may differ depending on your age, ovarian reserve, cause of infertility, previous IVF response, sperm quality, whether donor eggs or sperm are being used, and whether a fresh or frozen embryo transfer is planned.

For a broader explanation of IVF and who may benefit from it, see our main guide to IVF treatment.

How Long Does the IVF Process Take?

A typical IVF treatment cycle often takes around 3 to 6 weeks from the beginning of ovarian stimulation or cycle preparation through embryo transfer, although some protocols take longer. The complete journey can take additional time because patients may need fertility testing, counselling, consent, treatment planning, or preparation before the IVF cycle actually starts.

If embryos are frozen rather than transferred immediately, the embryo transfer takes place in a later menstrual cycle, extending the overall timeline.

IVF Treatment Process at a Glance

Step 1: Fertility Assessment Before IVF

The IVF process usually begins before any injections are given. The fertility specialist reviews the medical and reproductive history of the patient and, where applicable, their partner.

Testing may include:

• Ovarian reserve assessment
• Pelvic ultrasound
• Hormone blood tests
• Semen analysis
• Assessment of the uterus and reproductive anatomy
• Screening for certain infections before treatment

Not every patient requires exactly the same investigations. The purpose is to determine whether IVF is appropriate and help the fertility team design an individual treatment protocol.

Step 2: Your IVF Treatment Protocol Is Planned

Once testing is complete, the fertility specialist decides how the ovaries will be stimulated. You may hear terms such as:

• Antagonist or short protocol
• Long protocol
• Mild stimulation IVF
• Natural-cycle IVF

There is no single IVF protocol that is best for everyone. Today, many patients undergo an antagonist-style protocol, in which ovarian-stimulation medicines begin early in the menstrual cycle and another medicine is added later to prevent premature ovulation. Other patients may undergo down-regulation before stimulation as part of a longer protocol.

Step 3: Ovarian Stimulation Begins

In a natural menstrual cycle, usually one dominant follicle develops and releases an egg. During conventional IVF, fertility medicines are used to encourage multiple follicles to develop at the same time. 

This matters because not every follicle will necessarily contain a mature egg, not every egg will fertilise and not every fertilised egg will develop into an embryo suitable for transfer or freezing. Ovarian stimulation commonly involves daily injections containing gonadotrophins such as follicle-stimulating hormone (FSH). Stimulation often lasts approximately 8 to 14 days, although the exact duration varies according to how the ovaries respond.

What Can You Feel During Ovarian Stimulation?

Some patients experience:

• Abdominal fullness or bloating
• Breast tenderness
• Mild pelvic discomfort
• Headache
• Mood changes
• Bruising or tenderness at injection sites

Step 4: Ultrasound Scans Monitor Follicle Growth

While you are taking ovarian-stimulation medicines, the fertility team needs to see how your ovaries are responding. This usually involves one or more transvaginal ultrasound scans. The clinician measures the follicles, which are fluid-filled structures within the ovaries where eggs develop. Blood tests may also be used in some protocols to monitor hormone levels.

Monitoring allows the clinic to:

• Adjust medication doses when necessary
• Estimate how many follicles are developing
• Reduce the risk of an excessive ovarian response
• Decide when the eggs are ready for final maturation and collection

This is why two patients who start IVF on the same day may not have egg collection on exactly the same date.

Step 5: The Trigger Injection

When enough follicles have reached an appropriate stage of development, the clinic gives instructions for a trigger injection. The trigger helps the eggs complete their final maturation before egg retrieval. 

Depending on the IVF protocol and the patient's risk of ovarian hyperstimulation syndrome (OHSS), different trigger medicines may be used. The timing is extremely important because egg collection is scheduled according to the time of this injection. Patients should therefore take the trigger at exactly the time instructed by their fertility clinic.

Step 6: Egg Retrieval

Egg collection is one of the main procedural stages of IVF. It usually takes place approximately 34 to 36 hours after the trigger injection, before natural ovulation is expected to occur.

What Happens During Egg Retrieval?

The procedure is usually performed under sedation or another form of anaesthesia depending on the clinic. A fertility specialist:

1. Uses a transvaginal ultrasound probe to see the ovaries.
2. Guides a thin needle through the vaginal wall toward the ovarian follicles.
3. Withdraws the fluid from the follicles.
4. Sends the collected fluid immediately to the embryology laboratory.
5. The embryologist identifies the eggs within the follicular fluid.

The procedure itself commonly takes around 20–30 minutes, although this varies.

Patients may experience mild cramping, spotting, or pelvic discomfort afterward. Because sedation or anaesthesia may be used, patients usually need someone to accompany them home and should follow their clinic's instructions about driving and activities after the procedure.

Step 7: Sperm Is Collected and Prepared

A sperm sample is usually required on or around the day of egg retrieval. Depending on the treatment plan, the laboratory may use:

• A fresh semen sample
• Previously frozen sperm
• Donor sperm
• Surgically retrieved sperm in selected cases

The embryology laboratory processes the sample and selects suitable sperm for fertilisation.

Step 8: Eggs Are Fertilised in the Laboratory

Once mature eggs and sperm are available, fertilisation can take place. There are two commonly used methods.

Conventional IVF

The eggs are placed together with prepared sperm in laboratory culture conditions, allowing sperm to fertilise the eggs.

ICSI

Intracytoplasmic sperm injection (ICSI) involves an embryologist injecting a single sperm directly into a mature egg. ICSI may be recommended in situations such as significant male-factor infertility or certain previous fertilisation problems. ICSI is not automatically necessary for every IVF patient.

Step 9: The Embryologist Checks for Fertilisation

The eggs are assessed after fertilisation to determine how many have fertilised normally. This stage can be emotionally difficult because the numbers usually reduce at each step.

For example: Follicles seen on ultrasound → eggs collected → mature eggs → fertilised eggs → developing embryos → embryos suitable for transfer or freezing.

It is therefore completely normal for the final number of embryos to be lower than the number of follicles initially seen during stimulation. The exact numbers vary substantially between patients.

Step 10: Embryos Develop in the Laboratory

After fertilisation, embryos are cultured in carefully controlled laboratory conditions. Embryologists monitor how they develop. Embryos may be assessed at different stages, but transfer commonly takes place:

• Around day 2 or 3 after fertilisation, or
• At the blastocyst stage, usually around day 5

Not every fertilised egg reaches the blastocyst stage.

What If Genetic Testing of Embryos Is Planned?

Some patients may undergo preimplantation genetic testing (PGT) for specific medical indications. This is an additional procedure and is not a routine requirement for every IVF cycle. 

When PGT is performed, embryos are commonly cultured to the blastocyst stage, a small number of cells are biopsied, and the embryos are usually frozen while testing is completed. A suitable embryo can then be transferred during a later frozen embryo transfer cycle.

Step 11: Embryo Transfer

If a fresh embryo transfer is planned, a suitable embryo is placed into the uterus several days after egg retrieval. Embryo transfer is usually much simpler than egg collection.

During the procedure:

1. A speculum is placed in the vagina, similar to during a cervical screening examination.
2. A thin, soft catheter containing the embryo is passed through the cervix.
3. The embryo is gently released into the uterine cavity.
4. The catheter is removed and checked by the embryology team.

How Many Embryos Are Transferred?

More embryos do not automatically mean a better or safer IVF outcome. Transferring multiple embryos increases the chance of twins or higher-order multiple pregnancy, which increases risks for both the pregnant patient and babies. For many patients with a good prognosis, single embryo transfer is recommended when appropriate.

The decision depends on factors including:

• Age
• Embryo development and quality
• Previous IVF history
• Whether embryos have undergone genetic testing
• Clinical guidelines and local regulations

Fresh Embryo Transfer vs Frozen Embryo Transfer

Not every IVF cycle ends with an embryo being transferred immediately.

Fresh Embryo Transfer

An embryo is transferred several days after egg retrieval during the same treatment cycle.

Frozen Embryo Transfer

Suitable embryos are frozen and an embryo is transferred during a later menstrual cycle. A freeze-all strategy may sometimes be recommended because of:

• Risk of ovarian hyperstimulation syndrome
• Hormone levels or uterine lining concerns
• Planned embryo genetic testing
• Other clinical reasons

Step 12: Remaining Suitable Embryos May Be Frozen

If there are additional suitable embryos that are not transferred, they may be cryopreserved for future use. This can allow another attempt without repeating ovarian stimulation and egg retrieval. Frozen embryos may later be used for:

• Another pregnancy attempt if the first transfer is unsuccessful
• A future sibling pregnancy
• A later transfer when fresh transfer was not medically appropriate

Step 13: Progesterone Supports the Uterine Lining

Patients commonly receive progesterone around the time of embryo transfer. Progesterone helps support the lining of the uterus during the period when an embryo may implant. It may be given as:

• Vaginal capsules, tablets, pessaries, or gel
• Injections
• Other formulations depending on the treatment protocol

Continue the medication exactly as prescribed. Do not stop progesterone because of spotting or because you feel that a menstrual period may be starting unless your fertility team tells you to stop.

Step 14: The Waiting Period After Embryo Transfer

The period between embryo transfer and pregnancy testing is sometimes called the two-week wait, although the actual interval varies according to the stage of embryo transfer and clinic protocol. You generally do not need complete bed rest after embryo transfer. Normal gentle daily activity is usually possible unless your fertility team advises otherwise. Patients should follow their clinic's advice regarding:

• Exercise
• Sexual activity
• Medication
• Travel
• Work

Importantly, symptoms during this period cannot reliably tell you whether implantation has occurred. Bloating, breast tenderness, mild cramping, or no symptoms at all can occur because of fertility medicines and progesterone.

Step 15: Pregnancy Testing

Your fertility clinic will give you a specific date for a pregnancy test. This may involve a urine pregnancy test or a blood test measuring beta-human chorionic gonadotropin (beta-hCG). Avoid testing significantly earlier than advised. The trigger medicine used during IVF may contain or influence hCG, and testing too early can sometimes produce misleading results.

What Happens If the Pregnancy Test Is Positive?

If the result is positive, the fertility clinic will usually provide instructions about continuing medication and arranging follow-up. An early pregnancy ultrasound is generally performed several weeks later to:

• Confirm that the pregnancy is located inside the uterus
• Assess the gestational sac
• Check fetal development
• Confirm heartbeat when the pregnancy is far enough along
• Determine whether there is one pregnancy or a multiple pregnancy

The exact timing varies between clinics.

What Happens If the IVF Pregnancy Test Is Negative?

A negative result means that the embryo transfer did not result in an ongoing detectable pregnancy during that attempt. It does not necessarily mean that IVF can never work. The fertility team may review:

• How the ovaries responded to stimulation
• Number and maturity of eggs retrieved
• Fertilisation results
• Embryo development
• Embryo transfer
• Any remaining frozen embryos

What Can Change the Standard IVF Process?

The step-by-step process above describes a commonly used IVF cycle, but several situations can change it.

Can an IVF Cycle Be Cancelled Before Egg Retrieval?

Yes, although it is not common in every patient. A cycle may sometimes be modified or cancelled if:

• Too few follicles respond to stimulation
• The ovaries respond excessively
• Premature ovulation occurs
• Another medical concern develops

What Are the Main Risks During the IVF Process?

IVF is widely used, but it is still a medical treatment and has potential risks. These include:

• Side effects from fertility medicines
• Ovarian hyperstimulation syndrome (OHSS)
• Bleeding, infection, or injury associated with egg retrieval, although serious complications are uncommon
• Multiple pregnancy if more than one embryo implants
• Ectopic pregnancy
• Emotional and psychological stress during treatment

The Bottom Line

The IVF treatment process is a sequence rather than a single procedure. It begins with fertility assessment and treatment planning, followed by ovarian stimulation, ultrasound monitoring, a precisely timed trigger injection, egg retrieval, sperm preparation, laboratory fertilisation and embryo development.

A suitable embryo may then be transferred into the uterus during the same cycle or frozen for transfer later. Progesterone usually supports the uterine lining after treatment, and a pregnancy test is performed on the date advised by the fertility clinic.

Although this general pathway applies to many patients, there is no single IVF schedule that fits everyone. Your medication doses, number of monitoring appointments, fertilisation method, embryo-transfer timing, and overall timeline should be individually planned according to your fertility assessment and response to treatment.