For most couples beginning the IVF journey, the process feels both medically complex and emotionally overwhelming. Understanding what actually happens — step by step, from the first consultation through to the embryo transfer — removes much of the uncertainty and helps couples make informed decisions at each stage.

This guide explains the IVF process as practised at Balaji Horizon Women’s Hospital in Ahmedabad, under the clinical direction of Dr. Priyadatt Patel. The aim is to provide accurate, realistic information — not a simplified version that glosses over the variables that genuinely affect outcomes.

Before IVF Begins: Assessment and Planning

IVF is not a uniform treatment. It is a protocol that must be adapted to the specific clinical profile of each couple. Before stimulation begins, a thorough evaluation is essential:

For the Woman

Ovarian reserve assessment: Anti-Müllerian hormone (AMH), antral follicle count (AFC) on ultrasound, and baseline FSH/LH on day 2 or 3 of the cycle. These parameters determine the expected ovarian response and guide protocol selection and medication dosing.
Uterine evaluation: A detailed pelvic ultrasound assesses the endometrial lining, uterine cavity, and any structural abnormalities (fibroids, polyps, septum, or adhesions) that could affect implantation. A saline infusion sonohysterography or hysteroscopy may be recommended if the cavity appears abnormal.
Hormonal and infectious panel: Thyroid function, prolactin, haematological screen, blood group, and screening for infections including hepatitis B, hepatitis C, and HIV.

For the Male Partner

Semen analysis: Count, motility, morphology, and vitality. A single semen analysis should not be taken as definitive — values can vary significantly between samples.
DNA fragmentation: In cases of unexplained infertility, recurrent IVF failure, or poor embryo quality, sperm DNA fragmentation testing provides additional information that standard semen analysis cannot.

The pre-IVF evaluation informs the choice of stimulation protocol, the decision between conventional IVF and ICSI, and the timing of treatment.

Step 1: Ovarian Stimulation (Days 1–12 Approximately)

The goal of ovarian stimulation is to recruit multiple follicles simultaneously — unlike a natural cycle where only one follicle develops to ovulation. This is achieved with injectable gonadotropins (FSH, LH, or a combination), administered daily, usually beginning on day 2 or 3 of the menstrual cycle.

The choice of stimulation protocol depends on the woman’s ovarian reserve and clinical history:

GnRH antagonist protocol: Currently the most widely used approach. A GnRH antagonist is added mid-stimulation to prevent premature LH surge, providing flexible timing and significantly lower risk of ovarian hyperstimulation syndrome (OHSS).
Long GnRH agonist protocol: Involves downregulation before stimulation. Used in selected cases, particularly where better follicle synchronisation is needed.
Minimal stimulation / natural cycle IVF: Suitable for women with very low ovarian reserve or those with specific medical contraindications to conventional stimulation.

Monitoring During Stimulation

Regular monitoring is non-negotiable. Follicle growth is tracked with transvaginal ultrasound every 2–3 days, and hormone levels (estradiol, LH, progesterone) are measured to ensure the response is appropriate. Medication doses are adjusted based on these findings. A cycle that proceeds without adequate monitoring is a cycle at higher risk of poor outcomes, OHSS, or premature ovulation.

Step 2: Trigger Injection and Ovum Pick-Up (OPU)

When the lead follicles reach approximately 17–18 mm in diameter, a trigger injection is administered to induce final oocyte maturation. The timing is precise — oocyte retrieval is performed exactly 35 to 36 hours later.

Oocyte retrieval (OPU) is performed under short intravenous sedation as a day-care procedure. Using transvaginal ultrasound guidance, a fine needle is passed through the vaginal wall into each mature follicle, and the follicular fluid containing the oocyte is aspirated. The procedure takes 15 to 25 minutes and is well-tolerated by most women.

The fluid is immediately examined by the embryologist, who identifies and counts the mature oocytes (MII stage). The number retrieved depends heavily on the woman’s ovarian reserve and response to stimulation.

Step 3: Fertilisation in the Embryology Laboratory

On the day of oocyte retrieval, a semen sample is collected from the male partner. The sperm are prepared by gradient centrifugation to select the most motile fraction.

Fertilisation is achieved by one of two methods:

Conventional IVF insemination: Prepared sperm are placed in a dish with each oocyte, and natural fertilisation occurs in the incubator. Used when sperm parameters are reasonably normal.
ICSI (Intracytoplasmic sperm injection): A single sperm is injected directly into each mature oocyte using a micromanipulator. Indicated for male factor infertility, poor fertilisation in previous cycles, surgically retrieved sperm, or when sperm counts are very low.

Fertilisation is confirmed 16 to 18 hours later by the appearance of two pronuclei (2PN). A fertilisation rate of 60 to 80 percent of mature oocytes is typical with ICSI, though variability is common.

Step 4: Embryo Culture and Development (Days 2–5 After Fertilisation)

Fertilised embryos are cultured in specialised incubators that maintain precise temperature, pH, oxygen, and carbon dioxide levels to mimic the environment of the fallopian tube and uterus. Embryo development is assessed daily:

Day 2: 4-cell embryo
Day 3: 8-cell embryo (cleavage stage)
Day 4: Morula (16+ cells, beginning to compact)
Day 5–6: Blastocyst (inner cell mass and trophectoderm clearly differentiated)

Extended culture to the blastocyst stage (Day 5 or 6) allows for better embryo selection, as not all embryos that reach Day 3 will develop to blastocyst. Blastocyst transfer is associated with higher implantation rates per embryo transferred, though it requires sufficient numbers of embryos to justify extended culture.

Step 5: Embryo Transfer or Freeze-All Strategy

Embryo transfer may be performed fresh (in the same stimulation cycle) or the embryos may be frozen (vitrified) for transfer in a subsequent cycle.

Fresh Transfer

A fresh Day 3 or Day 5 transfer is performed when the endometrium is well-developed (ideally ≥8 mm, trilaminar pattern) and progesterone levels remain low, indicating that endometrial development is synchronised with embryo stage.

Freeze-All Strategy

Increasingly, a freeze-all approach is preferred in certain clinical scenarios:

Risk of OHSS (particularly in PCOS patients)
Elevated progesterone at the end of stimulation
Suboptimal endometrial development
Planned preimplantation genetic testing (PGT)

Frozen embryo transfer (FET) is performed in a subsequent cycle on a prepared endometrium. Frozen cycles allow for a more controlled uterine environment and have increasingly shown comparable (and in some categories, superior) outcomes to fresh transfers.

The Transfer Procedure

Embryo transfer is a simple, painless, outpatient procedure. A thin catheter is passed through the cervix into the uterine cavity under ultrasound guidance, and the embryo (or embryos) is deposited at the optimal location. The number of embryos transferred should be guided by the woman’s age, embryo quality, and clinical history — single embryo transfer (SET) is standard practice in most cases to minimise the risk of multiple pregnancy.

Step 6: The Two-Week Wait and Pregnancy Test

Following embryo transfer, progesterone support (via vaginal pessaries, injections, or oral capsules) continues to maintain the endometrial lining. Luteal phase support is necessary because the ovaries do not produce adequate progesterone after stimulation and oocyte retrieval.

A serum beta-hCG blood test is performed approximately 12 to 14 days after the embryo transfer to determine whether implantation has occurred. A positive result confirms biochemical pregnancy; follow-up ultrasound at 6 to 7 weeks confirms a viable intrauterine pregnancy with cardiac activity.

Understanding IVF Success Rates: A Realistic Perspective

IVF success rates are frequently cited in ways that mislead — either too optimistic or presented without the context that makes the numbers meaningful. The following is an honest framework:

Success rates decline progressively with age, particularly after 35 and more sharply after 40
Ovarian reserve (AMH, AFC) significantly influences the number of embryos available and therefore the cumulative chance of success across cycles
Embryo quality is the most important determinant of implantation — stimulation, laboratory conditions, and embryologist expertise all contribute
Uterine factors, including endometrial receptivity and structural normality, account for a meaningful proportion of IVF failures
Cumulative success rates across multiple cycles are substantially higher than per-cycle rates — for most women under 38 with reasonable reserve, two to three cycles provide a high cumulative probability of success

At Balaji Horizon Women’s Hospital, we discuss realistic, individualised expectations with each couple before treatment begins — not aggregate statistics that may not apply to their specific situation.

IVF for Special Circumstances

IVF with Endometriosis

Women with endometriosis undergoing IVF require careful protocol selection. Ovarian endometriomas can compromise the number of oocytes retrieved, and surgical removal before IVF must be weighed against the risk of further damaging ovarian reserve. A freeze-all strategy is commonly preferred in endometriosis, and careful attention to OHSS risk is required when using down-regulation protocols.

IVF in PCOS

PCOS patients are at elevated risk of OHSS due to a high antral follicle count and exaggerated response to stimulation. GnRH antagonist protocols with GnRH agonist triggering and a freeze-all approach represent the current evidence-based standard to minimise this risk while maintaining reasonable outcome rates.

Beginning Your IVF Journey at Balaji Horizon Women’s Hospital, Ahmedabad

Dr. Priyadatt Patel brings together advanced IVF treatment in Ahmedabad with careful, individualised clinical assessment. Every couple’s treatment plan is built around their specific laboratory parameters, medical history, and reproductive goals — not a standardised protocol applied uniformly.

If you are considering IVF or would like a second opinion on a previous cycle, contact Balaji Horizon Women’s Hospital at +91 9909496027. We also offer consultations for fertility preservation in Ahmedabad for those who are not yet ready to conceive but wish to plan ahead.