In vitro fertilization: 5 things to know before you start

Hearing “IVF” for the first time can make everything sound complicated. Medications, tests, eggs, sperm, embryos, laboratory, transfer. All of those concepts show up in a single consultation, and wanting to understand them before deciding is entirely reasonable.

In vitro fertilization is one of the most studied techniques in reproductive medicine. At the same time, every treatment shifts according to each person’s history. Here are five things worth having clear before you begin.

Who it can be an option for

In Vitro Fertilization (IVF) is a technique in which eggs and sperm are brought together in the laboratory to form embryos. One or more embryos are then transferred to the uterus.

It was first used mainly in cases of blocked fallopian tubes. Today it is indicated in very different situations: some cases of male factor, endometriosis, unexplained infertility. It is also part of the path for single people and LGBTQ+ couples.

That said, one name does not imply one protocol. Stimulation, the number of eggs retrieved, the laboratory technique, embryo culture, and the transfer strategy all vary from case to case.

1. Stimulation aims for several eggs, and not all of them advance

During an IVF cycle, hormonal medication is used to stimulate the development of several follicles. A procedure then retrieves the eggs.

The idea is to have more than one opportunity in the laboratory. And here is the point that causes the most confusion: not every follicle contains a mature egg, and not every retrieved egg becomes an embryo.

Many people arrive at IVF assuming a direct relationship between “number of eggs” and “number of babies”. The process has stages, and at each one there is a natural reduction in the number of cells that carry forward.

2. Not every egg fertilizes

ASRM puts general figures on it: around 70% of mature eggs fertilize, and roughly half of those fertilized continue to blastocyst.

These are population numbers, not a prognosis for any one person. They are useful for what they are: setting expectations. Some eggs not fertilizing does not mean the treatment failed, because embryo development happens in stages and each one has its own criteria.

A large part of the treatment happens in the laboratory, outside the consultation room

3. The embryology laboratory shapes a great deal

A central part of IVF happens outside the doctor’s office. After retrieval, embryologists work with the gametes and monitor embryo development over the following days.

Depending on the case, conventional fertilization or ICSI is used, the technique in which a single sperm is injected directly into the egg. ICSI is indicated in specific situations, such as certain male factors or a history of fertilization failure.

The laboratory may also use culture and monitoring systems that allow embryo development to be followed without removing the embryos from the incubator.

4. The prior evaluation counts as much as the procedure

Before starting IVF, the medical team needs to know your reproductive history and your particular circumstances. Depending on the case, the following are requested:

• Ovarian reserve assessment
• Gynecological ultrasound
• Hormone tests
• Semen analysis
• Uterine evaluation
• Genetic testing, when indicated
• Metabolic evaluations

The goal is to identify which factors could influence treatment and to build the strategy from there. At Ingenes, consultation and diagnosis brings together different areas to define which option fits best, from low complexity through IVF and Regenerative and Genetic Medicine tools where appropriate.

5. More technology does not always mean better treatment

Depending on the diagnosis, the team may add tools. ICSI in specific situations. Embryo genetic testing when there is a medical indication. Each one should have a clinical reason behind it.

Adding tests that do not change management makes the process more expensive without contributing anything. Before starting, these questions are legitimate and should be answered without evasion:

• Why are you recommending this technique?
• What problem does it aim to solve?
• What alternatives exist?
• What are its limitations?

When to see a specialist

If you have been trying for a while, have a history of endometriosis, altered semen parameters, tubal problems, diminished ovarian reserve, several previous treatments without success, or a medical condition that can affect your fertility, a specialized evaluation helps clarify what is happening.

It is worth moving it forward if you are over 40 or if there is a history that justifies an earlier assessment.

A consultation does not mean you will be doing IVF. It can be precisely the space to determine whether you need it or whether a different option suits you better.

Frequently asked questions

How many eggs does it take to achieve a pregnancy?

There is no set number. It depends on your age, your diagnosis, and how each stage progresses. ASRM’s general figures help frame the process, not predict your result.

Does IVF hurt?

Egg retrieval is done under sedation and takes a few minutes. The most uncomfortable part is usually the stimulation phase, because of abdominal bloating. Embryo transfer does not require anesthesia.

How long does a full cycle take?

Between stimulation and transfer, two to three weeks typically pass, plus the earlier testing period. If embryos are frozen, the transfer can be scheduled for a later cycle.

Do I need ICSI?

Only if there is an indication. It is used mainly for certain male factors or a history of fertilization failure. Applying it routinely, without a clinical reason, does not improve outcomes.

Starting with the process understood

IVF opens possibilities across very different diagnoses, and it still does not work as one identical formula for everyone. The outcome depends on several factors, and no general figure replaces an individual evaluation.

If you are considering starting, your first decision does not have to be choosing a technique. It can be finding a team that listens to your history, explains your options, and makes clear why each step is part of your treatment.

Starting IVF should not mean entering a process you do not understand. It should mean having the information to take part in decisions about your own care.