What is IVF?

Introduction
In Vitro Fertilization (IVF) is a multi-step assisted reproductive technology (ART) designed to facilitate conception outside the human body. A standard IVF cycle typically spans 3 to 6 weeks, from initial ovarian suppression to embryo transfer. The process is meticulously controlled and monitored to optimize the chances of a successful pregnancy.

The IVF Protocol: A Step-by-Step Medical Breakdown

1. Ovarian Stimulation (Approximately 8-12 Days)

• Protocol: The patient undergoes a course of injectable gonadotropins (FSH and/or LH analogs) to stimulate the ovaries to develop multiple ovarian follicles. This is a significant deviation from the natural cycle, which typically produces a single dominant follicle.
• Monitoring: Response to stimulation is closely tracked through serial transvaginal ultrasounds and serum estradiol level measurements. This allows for real-time medication adjustments to optimize follicular growth while minimizing the risk of Ovarian Hyperstimulation Syndrome (OHSS).

2. Final Oocyte Maturation & Trigger Shot

• Protocol: Once follicular maturation is confirmed via ultrasound (leading follicles typically reaching 18-20mm), a final “trigger” injection of hCG or a GnRH agonist is administered.
• Purpose: This injection mimics the natural LH surge, inducing the final stage of oocyte (egg) maturation within the follicles. The egg retrieval procedure is scheduled for precisely 36 hours post-trigger.

3. Oocyte Retrieval (Day 0)

• Procedure: A minor surgical procedure performed under intravenous sedation or anesthesia. Using transvaginal ultrasound guidance, a physician aspirates follicular fluid from each ovary via a thin needle.
• Laboratory Hand-off: The collected fluid is immediately transferred to the embryology laboratory, where the oocytes are isolated, identified, and placed in a specialized culture medium.

4. Fertilization & Embryo Culture (Days 1-6)

• Fertilization: On the day of retrieval, oocytes are fertilized using one of two primary methods:
  • Conventional Insemination: Oocytes are incubated with a prepared sample of motile sperm.
  • Intracytoplasmic Sperm Injection (ICSI): A single sperm is directly injected into each mature oocyte. This is standard for severe male factor infertility or prior IVF fertilization failure.
• Embryo Development: Fertilized eggs (now zygotes) are cultured in incubators that carefully control temperature, gas concentration, and pH. Development is assessed daily:
  • Day 1: Check for fertilization (2-pronuclear stage).
  • Days 2-3: Cleavage stage embryo development.
  • Days 5-6: Blastocyst formation. Blastocysts are graded on the expansion of the blastocoel cavity, and the quality of the inner cell mass (ICM) and trophectoderm (TE).

5. Embryo Transfer

• Timing: Transfer typically occurs at the blastocyst stage (Day 5/6) as it allows for better embryo selection and is more physiologically synchronous with the uterus.
• Procedure: The highest-quality embryo is loaded into a soft, thin catheter. Under ultrasound guidance, the physician passes the catheter through the cervix and deposits the embryo into the uterine cavity. This is a painless procedure that does not require anesthesia.

6. Luteal Phase Support & The Two-Week Wait

• Hormonal Support: Following the retrieval and transfer, the patient begins progesterone supplementation (vaginal, injectable, or oral). This is critical for preparing and maintaining the endometrial lining to support embryo implantation.
• Pregnancy Test: A quantitative serum beta-hCG test is performed 9-14 days after the embryo transfer to confirm pregnancy.