The IVF process step by step: what happens during treatment

An IVF cycle is a sequence of steps spread over several weeks, and much of the strain of it comes from not knowing what the next step will be. This guide walks through a cycle in the order it usually happens, from the first injections to the pregnancy test, and sets out what the Assisted Reproductive Technology (Regulation) Act, 2021 requires of a clinic along the way. It is written for patients and for the doctors who refer them. It publishes no success rates and no prices, because this directory holds neither for any clinic, and it is not clinical advice: your own protocol will be set by your clinic and may differ from the outline here. Everything it refers to can be found from the directory home.

What IVF is

The UK regulator, the Human Fertilisation and Embryology Authority (HFEA), describes it in one line: “IVF is a type of fertility treatment where fertilisation takes place outside the body.” In its usual form, “the woman has medicines (fertility hormones) to stimulate the ovaries to produce several eggs. The eggs are then collected and mixed with sperm in a laboratory.” Indian law uses a wider term. The ART Act defines assisted reproductive technology as “all techniques that attempt to obtain a pregnancy by handling the sperm or the oocyte outside the human body and transferring the gamete or the embryo into the reproductive system of a woman”, and IVF is the central example of it. The IVF treatment page covers who it is usually offered to, and the treatments guide sets it beside the alternatives.

How long a cycle takes

The HFEA calls IVF a cycle “as it involves a number of stages: suppressing natural hormone production, hormone treatment to boost egg supply, egg collection, mixing the eggs and sperm and finally, embryo transfer”. On timing it says “For most people, one cycle of IVF will take between four and six weeks.” Not everyone has every stage: “for medical reasons some women won't have the first stage of treatment (suppressing hormone production) which brings their treatment time down to around three weeks.”

The investigations that come before a cycle are not included in that time. The HFEA's advice about the run-up is worth taking seriously: “It's not something to take lightly, so take your time to think things through, ask questions and make sure you're clear on what's involved and what to expect.” If you have not yet been investigated, the guide to a first consultation describes the tests both partners usually have.

Before the cycle: counselling and consent

The law puts duties on the clinic before the first injection. Section 21(c) of the ART Act requires the clinic to “inform the commissioning couple and woman of the advantages, disadvantages and cost of the procedures, their medical side effects, risks including the risk of multiple pregnancy”. Under section 22(1), a clinic shall not perform any treatment or procedure without “the written informed consent of all the parties seeking assisted reproductive technology”. If embryos or gametes may be frozen during the cycle, section 22(2) adds a further requirement: written instructions about what should happen to them “in case of death or incapacity of any of the parties.”

Ask for the consent forms early and read them at home. They decide matters that are hard to revisit in the middle of a cycle, and the guide to your rights under the ART Act explains what each duty means in practice.

Step one: stimulating the ovaries

“Usually, the first step is to use medication to stimulate the ovaries to produce eggs.” There are two common approaches. In the first, the body's own hormones are switched off before stimulation begins; the HFEA explains that “This treatment, often called a long protocol, involves taking a daily injection or nasal spray to suppress hormone production.” A scan confirms the suppression, and then “hormone treatment (usually gonadotrophin) is started to boost the number of eggs the body produces.” The second approach changes the order. Some clinics use the “antagonist protocol”, which “involves taking medication (an antagonist) to suppress your hormones for a few days after you have taken the hormone medication (usually gonadotrophin) to boost the number of eggs the body produces.” Ask which approach the clinic proposes for you and why.

There are also forms of IVF with fewer drugs or none. The HFEA notes that “It's possible to have IVF with no fertility drugs at all (natural cycle IVF) or with fewer drugs (mild stimulation IVF and in vitro maturation [IVM]).” These may suit women who cannot take the drugs for medical reasons or prefer not to, and the HFEA is clear that they are generally less effective, so the choice is one to discuss with the clinic rather than assume.

Stimulation is watched closely: “Whichever way the ovaries are stimulated to produce eggs, you will be closely monitored for a few days by the clinic. This may involve having blood tests or ultrasound scans.” Monitoring is what keeps the main drug risk in check. Ovarian hyperstimulation syndrome, in the HFEA's description, “occurs in women who are very sensitive to the fertility medication resulting in too many eggs developing in the ovaries, which become very large and painful.” Its symptoms include a swollen or painful stomach, nausea and vomiting, shortness of breath, faintness and passing less urine, and “Patients who develop strong OHSS symptoms generally do so the week after egg collection.” Before you start, ask whom to call out of hours. The HFEA's advice is plain: “Never feel you are wasting the clinic's time.”

Step two: egg collection

When the follicles are ready, the eggs are collected. “The eggs will be collected whilst under sedation or general anaesthetic. The procedure takes around half an hour and you may feel a little sore or bruised.” On the same day the sperm is prepared: “Whilst the eggs are being collected, the man will be asked to come to the clinic to produce a sperm sample, or your donor sperm will be taken from the freezer, for mixing with your eggs.” A man who expects to find producing a sample on the day difficult can freeze one in advance, and where there is no sperm in the ejaculate it can sometimes be retrieved surgically; the surgical sperm retrieval page explains how.

In India, donor sperm comes through a registered bank, not from the clinic itself. Section 27(1) of the Act says “The screening of gamete donors, the collection, screening and storage of semen; and provision of oocyte donor, shall be done only by a bank registered as an independent entity under the provisions of this Act.” The guide to donor eggs and donor sperm sets out the rest of those rules.

Step three: fertilisation in the laboratory

“The eggs will be mixed with the sperm in a laboratory. The aim is for the eggs and sperm to fertilise to create an embryo.” Where sperm quality is a problem, the laboratory injects a single sperm into each egg instead. The HFEA explains that “If there are issues with the sperm quality such as low motility or numbers, a procedure called intracytoplasmic sperm injection (ICSI) may instead be used”. The ICSI page describes that procedure.

The Act sets hard rules for this stage of the work. Under section 24, “a woman shall not be treated with gametes or embryos derived from more than one man or woman during any one treatment cycle”, “a clinic shall never mix semen from two individuals for the procedures specified under this Act”, and “the embryos shall not be split and used for twinning to increase the number of available embryos”. Section 26(1) adds that “the clinic shall not offer to provide a couple or woman with a child of a pre-determined sex.” None of these is a matter of clinic preference.

Step four: watching the embryos develop

Fertilised eggs are kept in the laboratory for several days, and the HFEA says “the embryos are allowed to develop for between two and six days.” During that time the embryologist assesses them. In the HFEA's words, “If you have more than one embryo, your embryologist will use their training and expertise to select the best quality embryos using criteria such as” the number of cells, how fast they are dividing, whether the division is even and whether fragments of cells are present.

The clinic will also decide with you when to transfer. “Cleavage stage embryos are selected on day two or three of their development”, while “Blastocyst stage embryos are selected on day five of their development.” Waiting longer gives the embryologist more to judge by, but it carries its own risk, which the HFEA states directly: “not all embryos that are left to the blastocyst stage will survive and in some cases a couple could have no embryos available to transfer to the womb.” The blastocyst culture page explains the difference.

This is also the stage at which optional extras are offered. Of these add-ons, the HFEA says: “The fact is, there is no conclusive evidence that any of the commonly offered add-ons increase the chance of a pregnancy.” Genetic testing of embryos is limited by Indian law: section 25(1) says “The Pre-implantation Genetic testing shall be used to screen the human embryo for known, pre-existing, heritable or genetic diseases only.” The PGT page covers that testing.

Step five: preparing the womb and the transfer

While the embryos develop, the lining of the womb is prepared. “Medication will help to prepare the lining of the womb. This is usually taken as a pessary or gel”. Then comes the transfer itself: “Two to five days after fertilisation, the embryo(s) will be transferred to the womb. You won't need any kind of anaesthetic for this unless you have a condition that would make the procedure painful.”

How many embryos to transfer is the most important decision of the cycle. The Act sets a ceiling: “not more than three oocytes or embryos may be placed in the uterus of a woman during the treatment cycle”. That is a legal maximum, not a recommendation. The HFEA's position is that “If you have more than one good quality embryo available, it's now best practice for most women to have only one embryo put back in the womb and freeze the others (called an elective single embryo transfer or eSET).” The reason is the risk it calls the largest in fertility treatment: “The main risk of fertility treatment is a multiple birth.” Ask how the clinic decides the number, and ask before the day.

Step six: the wait and the pregnancy test

The days after transfer are often the hardest part. The HFEA's advice is: “You'll be given a date to do a pregnancy test. Although you'll understandably be excited at this stage, try not to do this early as you may get a false result.” It is worth knowing the warning signs of an ectopic pregnancy, because “All pregnant women are at risk of having an ectopic pregnancy but women having IVF may be more at risk.” One-sided pain low in the abdomen, vaginal bleeding or an unusual discharge are reasons to call the clinic at once.

Many people worry that stress during the wait will affect the result. The HFEA's reading of the evidence is reassuring: “there is no conclusive evidence that stress impacts on fertility treatment outcomes.”

Embryos that are not transferred

A cycle often produces more good embryos than are transferred. “Often several good quality embryos will be created. In these cases, it's normally best practice to freeze the remaining embryos because putting two embryos back in the womb increases your chance of having twins or triplets, which carries health risks.” Frozen embryos can be used in a later transfer without another round of stimulation. What happens to embryos you never use is a legal question as much as a medical one, and the guide to embryo and gamete storage sets out the consent and storage rules. The embryo freezing page explains the procedure.

If a cycle does not work

Not every cycle ends in a pregnancy, and the HFEA's advice on what to do next is unhurried: “Many experts recommend that you wait for a couple of months after treatment before trying again. This gives you a break from the stress of treatment and a chance for your body to recover.” Whatever you decide, keep the paperwork. Under section 21(h), “the clinics shall issue to the commissioning couple or woman a discharge certificate stating details of the assisted reproductive technology procedure performed on the commissioning couple or woman”, and that record matters if you later move to another clinic.

Where a cycle can be done

IVF is laboratory work, and under the ART Rules it belongs to a Level 2 clinic, described as one of the “ART clinics where all/advanced investigations, diagnostic and therapeutic procedures in ART are carried out.” A Level 1 clinic can investigate and offer IUI but not IVF. The guide to clinic levels explains the difference, and the guide to choosing between IVF and IUI covers when the simpler treatment is enough.

The clinics index covers every state, and a city page such as Ahmedabad lists the registered clinics there. Pages such as IVF in Bengaluru and ICSI in Pune list the clinics in a city that name the treatment on their own website. That is the clinic's own statement, not a check of its laboratory. Each clinic page shows the registration number recorded in the National ART & Surrogacy Registry extract, and the level where the extract records one; where it does not, the clinic's certificate is the authority. The fertility doctors index lets you look a doctor up by name, and the treatments index describes every procedure in this guide.

Questions to ask before the cycle starts

• Which stimulation approach do you propose for me, and why that one?
• How often will I be monitored, and who decides when the eggs are collected?
• What are the warning signs of hyperstimulation, and whom do I call out of hours?
• Will fertilisation be by IVF or ICSI, and what decides it?
• On which day do you usually transfer, and how do you decide how many embryos to transfer?
• Which add-ons do you offer, and what does each one add to the cost?
• What happens to embryos that are not transferred, and what will I be asked to sign about them?
• Is the laboratory registered at Level 2, and is the certificate on display?

For doctors referring a patient

A patient who arrives knowing the sequence of a cycle asks better questions and copes better with the waiting. It helps to send previous investigations with their dates and any earlier stimulation, with the drugs and the response, so the clinic can plan the protocol. If the patient has a condition that raises the risk of hyperstimulation, or one that may make anaesthesia or transfer difficult, say so in the referral. Refer for IVF to a clinic whose laboratory is registered at Level 2.

Where this guide comes from

Statements about the law are quoted from the Assisted Reproductive Technology (Regulation) Act, 2021, and the description of clinic levels from the ART Rules, 2022. The description of each step is quoted from the patient pages of the UK's Human Fertilisation and Embryology Authority (HFEA). Clinics in India follow the same sequence but differ in detail, and your clinic will tell you which protocol it uses. Facts about clinics come from the National ART & Surrogacy Registry extract this directory holds and from each clinic's own website. Nothing in this guide is clinical advice, and nothing in it is sponsored.