What IVF Actually Involves, Start to Finish

The honest picture, with numbers

IVF is a sequence of procedures with a defined shape, a defined timeline and published outcomes. Knowing the shape in advance removes a surprising amount of the fear, and knowing the outcome data protects you from the parts of the industry that sell hope by the item.

Scale first. The HFEA reports that in 2023, 52,400 patients had over 77,500 IVF cycles at licensed UK clinics, and that babies born from IVF rose from about 8,700 in 2000 to 20,700 in 2023.

Outcomes by age, using HFEA figures for birth rate per embryo transferred: 35% for patients aged 18 to 34, 26% at 35 to 37, 18% at 38 to 39, 10% at 40 to 42, and 5% at 43 to 44. Those are per-embryo-transfer figures, so a full cycle that includes more than one transfer gives a higher cumulative chance than any single row suggests. The shape of the curve is unambiguous, and the age that matters is the age of the egg.

Timeline: the NHS puts a full cycle at around 3 to 6 weeks; the HFEA says most people find a cycle takes between four and six weeks. Cost in the UK: the HFEA gives an average of around £5,000 for one cycle, noting that quoted prices often exclude fertility drugs, embryo freezing and administration.

Multiple births, which used to be the main safety problem with IVF, are now rare. The HFEA reports the IVF multiple birth rate has fallen to 3.4%, one of the lowest in the world, down from around 28% in the early 1990s.

What actually happens, step by step

1. Suppressing your natural cycle

Depending on protocol, you may take a daily injection or nasal spray for around 2 to 3 weeks to stop your ovaries releasing eggs naturally, followed by a scan to check it has worked. Not every protocol includes this stage.

2. Stimulating the ovaries

Daily injections of gonadotrophin for roughly 10 to 14 days encourage multiple follicles to develop, monitored by scans and sometimes blood tests. NG257 requires clinics providing gonadotrophin stimulation to have protocols for preventing, diagnosing and managing ovarian hyperstimulation syndrome. The HFEA notes around a third of women have mild OHSS, usually manageable at home with pain relief; moderate or severe OHSS is less common, and severe OHSS can rarely be life-threatening.

3. Egg collection

Eggs are collected with a needle passed through the vaginal wall into each ovary under ultrasound guidance. The NHS puts this at around 20 minutes; the HFEA says about half an hour. NG257 recommends offering conscious sedation, describing it as a safe and acceptable method of providing analgesia, and advises against follicle flushing where there are at least 3 follicles because it does not increase eggs retrieved or pregnancy rates and increases both duration and pain.

4. Fertilisation in the laboratory

Eggs are mixed with sperm, or — where sperm quality is a problem — a single sperm is injected into each egg by ICSI. You are usually called the next day with the number of embryos created. Embryos are then grown for between two and six days, which allows the embryologist to select the strongest.

5. Embryo transfer

One embryo is usually placed into the uterus through a thin catheter. NG257 recommends ultrasound-guided transfer because it improves pregnancy rates, and single embryo transfer in the first full cycle under 37, extending to single transfer where a top-quality blastocyst is available at any age. It advises never transferring more than 2 embryos in one cycle, and says bed rest of more than 20 minutes afterwards does not improve the outcome. Remaining good-quality embryos should be offered cryopreservation.

6. The wait, and the test

The NHS says a pregnancy test is given with a date to use it, around 16 days after embryo transfer, and that taking it on the given date matters for accuracy. A positive result leads to a scan at around 7 weeks to check for a heartbeat.

The add-ons, and how to handle them

This is where money and hope meet, so it is worth having the specifics. NG257 recommends against a list of commonly sold extras: endometrial scratch as pre-treatment, hysteroscopy as pre-treatment, endometrial receptivity testing including receptivity arrays and endometrial microbiome analysis, immunological agents including intralipids, intravenous immunoglobulins and steroids, pre-implantation genetic testing for aneuploidy to improve live birth rates, and assisted hatching. In the UK the HFEA maintains a rated list of treatment add-ons; when its improved ratings launched in 2023, none of the 13 add-ons assessed was rated green overall.

Two questions cut through most of it: what does the HFEA rate this, and which recommendation in NG257 covers it. A clinic that cannot answer either is not offering you evidence.

What to do next

1. Ask for the cumulative live birth rate per stimulation cycle for your age band, not the clinic's overall rate, which is dominated by younger patients.
2. Get a written cost breakdown separating treatment, drugs, freezing, storage and administration. The HFEA warns that quoted prices frequently exclude the first three.
3. Ask which protocol you are on and why, and how OHSS will be monitored and prevented.
4. Ask what the plan is for the embryos you do not transfer, and what storage will cost each year.
5. Check every proposed add-on against the HFEA ratings and NG257 before agreeing to pay for it.
6. Take the counselling. The NHS notes it is recommended for anyone having IVF, and clinics should offer it before, during and after treatment.

When to seek help

NG257 recommends offering IVF to people who have not reached their 42nd birthday where there is a diagnosed cause of infertility for which other treatments are unsuitable or have not been successful, or unexplained fertility problems after 2 years of regular unprotected vaginal intercourse, or where conception has not occurred after 12 cycles of artificial insemination with 6 or more by IUI. It defines a full cycle as one episode of ovarian stimulation plus the transfer of any resulting fresh and frozen embryos.

Getting to that point starts earlier. NG257 recommends assessment of both partners after 1 year of unprotected vaginal intercourse and referral at first presentation from age 36, or where either partner has a suspected or known clinical cause of infertility. Because IVF eligibility is generally counted from 2 years of trying, the year you spend waiting to be investigated is a year subtracted from your options later — which is the strongest practical argument for asking early rather than at the point you are certain.