What is the step-by-step process for in vitro fertilization (IVF)?

From the Guidelines

In vitro fertilization (IVF) is a multi-step fertility treatment that involves ovarian stimulation, egg retrieval, fertilization, embryo development, and transfer, with the goal of achieving a successful pregnancy, and according to the most recent guidelines, elective single embryo transfer (eSET) is considered the preferable approach towards safe and effective ART 1. The process begins with ovarian stimulation, where medications like Gonal-F, Follistim, or Menopur are administered daily for 8-12 days to stimulate the ovaries to produce multiple eggs. These medications contain follicle-stimulating hormone (FSH) and luteinizing hormone (LH) to promote follicle development. During this phase, regular monitoring through blood tests and ultrasounds tracks follicle growth. Once follicles reach optimal size (about 18-20mm), a trigger shot of human chorionic gonadotropin (hCG) or GnRH agonist is given to finalize egg maturation. Approximately 36 hours later, egg retrieval occurs under sedation, where a physician uses ultrasound guidance to extract eggs with a thin needle through the vaginal wall. The collected eggs are then combined with sperm in the laboratory either through conventional insemination or intracytoplasmic sperm injection (ICSI), where a single sperm is directly injected into each egg. The fertilized eggs develop into embryos over 3-5 days, during which embryologists monitor their growth.

Key Considerations for Embryo Transfer

• The highest quality embryos are then transferred into the uterus using a thin catheter passed through the cervix, or frozen for future use, with eSET being the recommended approach to minimize the risk of multiple pregnancies and related medical risks 1.
• Following transfer, progesterone supplements (vaginal suppositories, injections, or oral tablets) are prescribed to support the uterine lining and potential implantation.
• A pregnancy test is conducted about two weeks after the embryo transfer to determine if the procedure was successful.

Guidelines and Recommendations

• The European Society of Human Reproduction and Embryology (ESHRE) guideline on the number of embryos to transfer during IVF/ICSI provides healthcare professionals with clear advice on best practice in the decision-making process, based on the best evidence currently available 1.
• The guideline assesses the medical and non-medical factors that are to be taken into consideration when deciding on the number of embryos to transfer, with the aim of providing the best available evidence to healthcare professionals and patients.

From the FDA Drug Label

The ovarian stimulation treatment with recombinant FSH or human menopausal gonadotropin (hMG) was initiated on day 2 or 3 of a normal menstrual cycle. Oocyte pick-up (OPU) followed by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) as well as embryo transfer (ET) were subsequently performed.

The step-by-step process for in vitro fertilization (IVF) involves:

• Ovarian stimulation: treatment with recombinant FSH or human menopausal gonadotropin (hMG) initiated on day 2 or 3 of a normal menstrual cycle.
• Oocyte pick-up (OPU): retrieval of eggs from the ovaries.
• IVF or ICSI: fertilization of the eggs with sperm using either IVF or ICSI.
• Embryo transfer (ET): transfer of the resulting embryos into the uterus. 2

From the Research

Step-by-Step Process for In Vitro Fertilization (IVF)

The process of IVF involves several steps, including:

• Ovarian stimulation: This is the first step in the IVF process, where medications are used to stimulate the ovaries to produce multiple eggs 3.
• Follicle development: The growth and development of follicles in the ovaries is crucial for successful IVF. Research has shown that decremental serum FSH concentrations during the follicular phase of the menstrual cycle are required for single dominant follicle selection 3.
• Egg retrieval: Once the follicles have matured, the eggs are retrieved through a minor surgical procedure 4.
• Fertilization: The retrieved eggs are then fertilized with sperm in a laboratory dish 5.
• Embryo culture: The resulting embryos are cultured in the laboratory for 3-5 days before being transferred to the woman's uterus 6.
• Embryo transfer: The final step in the IVF process is the transfer of the embryos to the woman's uterus, where they will implant and develop into a fetus 7.

Ovarian Stimulation Protocols

Different ovarian stimulation protocols can be used in IVF, including:

• Minimal stimulation IVF: This protocol uses lower doses of medications to stimulate the ovaries, resulting in fewer eggs being produced 4.
• Gonadotrophin-releasing hormone (GnRH) antagonist protocols: These protocols use GnRH antagonists to prevent premature ovulation and allow for more control over the stimulation process 5, 6.
• Oral GnRH antagonist protocols: These protocols use oral medications, such as elagolix, to suppress ovulation and are less invasive and cheaper than injectable GnRH antagonists 7.

Poor Responders

Poor responders are women who do not respond well to ovarian stimulation and may require different protocols, such as:

• High doses of gonadotrophins: These may be required to stimulate the ovaries in poor responders 6.
• GnRH antagonist protocols: These protocols can be effective in poor responders by preventing premature ovulation and allowing for more control over the stimulation process 6.