How IVF works

In vitro fertilisation (IVF) means eggs and sperm are brought together in a laboratory rather than inside the body. The resulting embryo is grown for a few days and then placed in the uterus. A full cycle usually takes around 3 to 6 weeks.

What IVF is

IVF is a treatment in which the ovaries are stimulated with hormones, eggs are collected, and the eggs are mixed with sperm in a laboratory. Embryos that develop are watched for several days, and one is then placed in the uterus.

In many cycles, fertilisation is helped by ICSI, where a single sperm is injected into each mature egg. Suitable embryos that are not transferred may be frozen for later use.

One IVF cycle usually takes about 3 to 6 weeks from the start of medication to the pregnancy test, according to the HFEA. Embryos are usually watched in the lab for 2 to 6 days before transfer.

Who it is for

• Couples where other treatments have not worked or are unlikely to work
• Blocked or damaged fallopian tubes
• Male factor infertility, often combined with ICSI
• People who need embryo genetic testing (PGT)

Your chance of success depends mainly on the woman's age and the cause of infertility. Your doctor will explain what IVF can and cannot offer in your situation.

Step by step

1. Stimulation and monitoringDaily hormone injections encourage several follicles to grow. Ultrasound scans and blood tests every few days check progress. Most stimulations last 8 to 14 days.
2. Trigger injectionWhen the eggs are nearly ready, a trigger shot completes their maturation. Egg collection is timed for about 36 hours later.
3. Egg collectionUnder sedation, a thin needle guided by vaginal ultrasound collects eggs from each ovary. It takes around 20 to 30 minutes.
4. FertilisationEggs are mixed with sperm, or a single sperm is injected into each mature egg (ICSI). On average, about 70% of mature eggs fertilise.
5. Embryo cultureEmbryos are watched in the lab for five to six days. About half of fertilised eggs reach the blastocyst stage.
6. Transfer and progesteroneAn embryo is placed in the uterus through a thin catheter. Progesterone supports the uterine lining, and many people continue it through the first trimester.
7. Pregnancy testA blood or urine test is done around 9 to 16 days after transfer. If positive, an early scan follows at around 7 weeks of pregnancy.

Not every egg becomes an embryo. Cleveland Clinic reports that, on average, about 70% of mature eggs fertilise and about half of fertilised eggs reach the blastocyst stage. A blood pregnancy test is usually done about 9 to 14 days after transfer.

During monitoring, follicles larger than about 14 millimetres usually contain mature eggs, which helps the team time the trigger shot. The egg collection itself usually takes less than 10 minutes.

What it feels like

• Injections: most people learn to give them at home; bloating is common late in stimulation.
• Egg collection: done under sedation or anaesthesia; mild soreness or bruising afterwards is common.
• Recovery: most people return to normal activities soon after, but should not drive for 24 hours after anaesthesia.
• Embryo transfer: usually no anaesthetic needed; it feels similar to a smear test.

Cleveland Clinic lists common side effects of the medicines:

• Bloating, tummy ache or enlarged ovaries
• Headaches, hot flushes or nausea
• Bruising where injections are given

The wait between transfer and the test is often the hardest part emotionally. Plan gentle activities and lean on people you trust.

How to prepare

• Expect several appointments and tests before your cycle starts
• Read the consent forms carefully, including what happens to any frozen embryos
• Talk with your doctor about healthy lifestyle changes before treatment
• Plan emotional support, especially in case a cycle is not successful

Risks and side effects

ASRM also notes a rare heterotopic pregnancy, with one pregnancy in the womb and one outside it, in about 1% of cases. The background risk of birth defects is 2 to 3%, and this may be slightly higher when ICSI is used. Miscarriage risk ranges from about 15% in the 20s to over 50% in the 40s.

Seek urgent care for severe abdominal pain, shortness of breath, vomiting or being unable to pass urine during or after stimulation.

How DBN does it

• Embryos are cultured to day 5 (blastocyst) as part of IVF.
• One embryo is transferred at a time (single embryo transfer) to reduce twin risk.
• Remaining embryos can be vitrified and stored at −196 °C.
• IVF & ICSI is about 450,000 THB per cycle including blastocyst culture, over 4–6 weeks. First consultation is free; prices are confirmed at consultation.

Questions & answers

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