IVF Step by Step: What Really Happens During Treatment

Introduction — What Is IVF and How Long Does It Take?

In vitro fertilization (IVF) is one of the most effective forms of assisted reproductive technology, helping millions of people worldwide build their families. While the concept is well-known, the actual day-by-day experience of an IVF cycle remains a mystery to many patients until they are in the middle of it.

A complete IVF cycle typically takes 4 to 6 weeks from the start of ovarian stimulation to the pregnancy test. This timeline includes approximately 10 to 14 days of hormone injections, a minor surgical procedure for egg retrieval, embryo culture in the laboratory, embryo transfer, and the emotionally charged two-week wait.

Understanding each step before you begin can significantly reduce anxiety and help you feel more in control. This guide walks you through every stage of the IVF process — what happens, why it matters, and what you should expect physically and emotionally.

Step 1: Initial Consultation and Testing

Your IVF journey begins well before any injections. The initial consultation and testing phase typically takes 2 to 4 weeks and lays the groundwork for your personalized treatment protocol.

What Happens During the Consultation

During your first appointment, your fertility specialist will review your complete medical history — including any previous pregnancies, miscarriages, fertility treatments, surgeries, and chronic conditions. Your partner's medical history is equally important if you are using a partner's sperm.

Required Testing

Both partners will undergo a series of diagnostic tests. For the female partner, these typically include:

• Ovarian reserve testing: Blood tests for AMH (Anti-Müllerian Hormone), FSH (Follicle-Stimulating Hormone), and estradiol levels, typically measured on day 2 or 3 of your menstrual cycle.
• Transvaginal ultrasound: To assess the uterus, ovaries, and antral follicle count (AFC), which helps predict how you will respond to stimulation medications.
• Infectious disease screening: Tests for HIV, hepatitis B and C, syphilis, and other infectious conditions required before any IVF procedure.
• Uterine cavity evaluation: Either a saline infusion sonohysterogram (SIS) or hysteroscopy to check for polyps, fibroids, or scar tissue that could interfere with implantation.

For the male partner, testing includes:

• Semen analysis: Evaluates sperm count, motility (movement), morphology (shape), and other parameters.
• Infectious disease screening: Same panel as the female partner.

Step 2: Ovarian Stimulation

Ovarian stimulation is the phase most people associate with IVF. Using daily hormone injections, the goal is to stimulate the ovaries to produce multiple mature eggs — rather than the single egg that naturally develops each cycle.

The Day-by-Day Experience

Stimulation typically begins on day 2 or 3 of your menstrual cycle and continues for approximately 10 to 14 days. Here is what a typical stimulation cycle looks like:

• Days 1-4: You start daily subcutaneous injections of gonadotropins (FSH and sometimes LH). These are small injections into the fatty tissue of your abdomen or thigh. Most patients learn to self-administer these after training from their clinic. You may feel mild bloating during these early days.
• Days 5-7: You return to the clinic for your first monitoring appointment — a transvaginal ultrasound to measure follicle growth and a blood test to check estradiol levels. Based on results, your medication dosage may be adjusted. Around day 5 or 6, a GnRH antagonist (such as Cetrotide or Ganirelix) is often added to prevent premature ovulation.
• Days 8-10: Monitoring appointments become more frequent — typically every 1 to 2 days. Follicles should be growing steadily, measuring 16-20mm by day 9 or 10. You may experience noticeable bloating and mild pelvic discomfort as your ovaries enlarge.
• Days 11-14: When at least 2 to 3 follicles reach 18mm or larger and estradiol levels are appropriate, your doctor determines you are ready for the trigger shot. Stimulation injections stop on this day.

Monitoring During Stimulation

Throughout the stimulation phase, you will attend approximately 4 to 6 monitoring appointments. Each appointment involves a transvaginal ultrasound and blood draw. The ultrasound measures the number and size of growing follicles, while the blood test tracks your estradiol and progesterone levels to ensure your body is responding safely and effectively.

Step 3: The Trigger Shot

The trigger shot is one of the most precisely timed events in the entire IVF cycle. It is administered approximately 35 to 36 hours before your scheduled egg retrieval.

What the Trigger Shot Does

The trigger injection contains human chorionic gonadotropin (hCG) or a GnRH agonist (such as Leuprolide). It mimics the body's natural LH surge, which is the signal that tells eggs to complete their final maturation phase — a process called meiotic maturation. Without this trigger, the eggs cannot be successfully retrieved.

Types of Trigger Shots

• hCG trigger (Ovidrel, Pregnyl): The traditional trigger. Provides a strong and sustained signal for final egg maturation. It has a longer half-life, which means it continues supporting the corpus luteum after retrieval. However, it carries a higher risk of ovarian hyperstimulation syndrome (OHSS) in high responders.
• GnRH agonist trigger (Leuprolide, Buserelin): Often used for patients at high risk of OHSS, such as those with PCOS or very high follicle counts. This trigger causes a shorter, more natural LH surge and significantly reduces OHSS risk. However, it requires additional luteal phase support after retrieval.
• Dual trigger: A combination of both hCG and GnRH agonist, sometimes used to optimize egg maturity while managing OHSS risk.

Step 4: Egg Retrieval

Egg retrieval (also called oocyte retrieval or follicular aspiration) is a minor surgical procedure performed under sedation or light general anesthesia. It is typically scheduled 35 to 36 hours after the trigger shot.

The Procedure

Egg retrieval takes approximately 20 to 30 minutes. Here is what happens:

1. You will be given intravenous (IV) sedation by an anesthesiologist. You will be asleep but breathing on your own — this is not general anesthesia requiring a breathing tube.
2. Using transvaginal ultrasound guidance, the doctor inserts a thin needle through the vaginal wall and into each ovary to aspirate the follicular fluid, which contains the eggs.
3. The fluid is immediately passed to the embryology laboratory, where embryologists identify and isolate the eggs under a microscope.
4. Once all accessible follicles have been aspirated, the procedure is complete.

The number of eggs retrieved varies widely depending on age, ovarian reserve, and response to stimulation. Typically, 8 to 15 eggs are retrieved, though some patients yield fewer and others more.

Recovery and What to Expect

You will spend 1 to 2 hours in the recovery area after the procedure. Most patients can go home the same day. Common post-retrieval experiences include:

• Mild to moderate cramping and pelvic discomfort (similar to menstrual cramps)
• Bloating and a feeling of fullness
• Light vaginal spotting or bleeding
• Fatigue from the sedation

Most patients return to normal activities within 24 to 48 hours. Your clinic will provide specific aftercare instructions, including warning signs of OHSS (severe bloating, rapid weight gain, shortness of breath, severe pain) that require immediate medical attention.

Step 5: Fertilization and Embryo Development

After egg retrieval, the embryology laboratory takes over. This phase lasts 5 to 6 days and is entirely out of your hands — but your clinic will typically provide daily updates on how your embryos are developing.

The Lab Process Day by Day

• Day 0 (Retrieval Day): Eggs are retrieved and placed in a culture medium. The sperm sample is processed and prepared for fertilization. If using conventional IVF, eggs and sperm are combined in a dish. If using ICSI (intracytoplasmic sperm injection), a single sperm is injected directly into each mature egg.
• Day 1 (Fertilization Check): Approximately 16 to 18 hours after insemination, embryologists check for signs of fertilization. A normally fertilized egg shows two pronuclei (one from the egg, one from the sperm). You will receive a fertilization report — typically, 70-80% of mature eggs fertilize successfully.
• Day 2: The fertilized eggs (now called embryos) should have divided into 2 to 4 cells. Embryologists assess cell number and symmetry.
• Day 3: Embryos should have 6 to 8 cells. At this stage, embryos can be graded based on cell number, fragmentation, and symmetry. Some clinics may transfer or freeze embryos at day 3, though most now prefer waiting until day 5 or 6.
• Day 4: The embryo compacts into a morula — a solid ball of cells. This is a transitional stage where individual cells become harder to count.
• Day 5-6 (Blastocyst Stage): The embryo develops into a blastocyst, with two distinct cell types: the inner cell mass (which becomes the fetus) and the trophectoderm (which becomes the placenta). A fluid-filled cavity also forms. Blastocysts are graded on expansion, inner cell mass quality, and trophectoderm quality. Approximately 30-50% of day 3 embryos will develop into usable blastocysts, though this rate varies with age and embryo quality.

Step 6: Embryo Transfer

Embryo transfer is the final clinical procedure in the IVF process. It is a relatively simple procedure, similar to a Pap smear, that typically takes 5 to 10 minutes and does not require sedation.

Fresh vs. Frozen Embryo Transfer

• Fresh transfer: The embryo is transferred 3 to 5 days after egg retrieval, in the same cycle. The advantage is a shorter overall timeline. However, the uterine lining may not be optimally receptive immediately after the high hormone levels of ovarian stimulation.
• Frozen embryo transfer (FET): All viable embryos are frozen (cryopreserved) after development, and one is thawed and transferred in a subsequent cycle — typically 4 to 6 weeks later. This allows your body to return to its natural hormonal state, which some studies suggest improves implantation rates. FET also allows time for genetic testing (PGT-A) if desired.

The Transfer Procedure

During the transfer:

1. You lie on an examination table with a full bladder, which helps the doctor visualize the uterus via abdominal ultrasound.
2. A speculum is inserted into the vagina to visualize the cervix.
3. A soft, thin catheter containing the embryo(s) is guided through the cervix into the uterus under ultrasound guidance.
4. The embryo is gently released into the uterine cavity.
5. The catheter is checked under a microscope to ensure the embryo was successfully transferred.

After the Transfer

You will rest for 15 to 30 minutes at the clinic before going home. Most clinics recommend taking it easy for the remainder of the day but do not require strict bed rest. Normal activities can resume the following day, though you should avoid strenuous exercise, heavy lifting, and hot baths until after the pregnancy test.

Progesterone supplementation (injections, suppositories, or oral tablets) begins either before or on the day of transfer and continues through the two-week wait — and often through the first trimester if pregnancy is achieved.

Step 7: The Two-Week Wait and Pregnancy Test

The period between embryo transfer and the pregnancy test is often described as the most emotionally challenging phase of IVF. Known as the "two-week wait" (TWW), this period typically lasts 10 to 14 days.

What Happens During the Wait

If the embryo implants, it will begin producing human chorionic gonadotropin (hCG) — the pregnancy hormone. Implantation typically occurs 1 to 5 days after a blastocyst transfer (or 6 to 10 days after a day 3 transfer).

Managing the Emotional Experience

The two-week wait is challenging because:

• Progesterone supplementation can cause symptoms that mimic both early pregnancy and an impending period — breast tenderness, bloating, cramping, fatigue, and mood swings.
• It is too early for reliable home pregnancy tests. Testing too early can produce false negatives that cause unnecessary distress.
• The emotional stakes are extraordinarily high after weeks of injections, procedures, and hope.

Strategies that help include staying busy with light activities, practicing mindfulness or meditation, limiting symptom-searching online, and leaning on your support network.

The Pregnancy Test

Your clinic will schedule a beta hCG blood test approximately 10 to 14 days after transfer. This quantitative blood test measures the exact level of hCG in your blood:

• A level above 25 mIU/mL is generally considered positive.
• A second blood test 48 to 72 hours later should show hCG levels roughly doubling, indicating a normally progressing pregnancy.
• If the test is positive, an ultrasound is scheduled approximately 2 to 3 weeks later to confirm a gestational sac and fetal heartbeat.

IVF Medications Guide Table

Understanding your medications is essential for a smooth IVF cycle. Below is a comprehensive guide to the most common IVF medications, organized by their purpose in the treatment cycle.

IVF Timeline Infographic

The following text-based timeline provides a quick overview of the typical IVF cycle, from preparation through the pregnancy test. Individual timelines vary based on your protocol and response.