From the Guidelines
In Vitro Fertilization (IVF) is a multi-step fertility treatment that typically takes 2-3 weeks per cycle, and the most recent guideline from 2024 1 emphasizes the importance of evidence-based decision-making in the IVF process. The process begins with ovarian stimulation using medications like Gonal-F, Follistim, or Menopur (gonadotropins) for 8-12 days to produce multiple eggs. These medications are usually self-administered as daily injections. During this phase, regular monitoring via blood tests and ultrasounds tracks follicle development. When 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, eggs are retrieved through a transvaginal ultrasound-guided procedure under sedation. The collected eggs are then fertilized with sperm in the laboratory either through conventional insemination or intracytoplasmic sperm injection (ICSI). The resulting embryos are cultured for 3-5 days, during which some patients may take progesterone supplements (vaginal suppositories, injections, or oral tablets) to prepare the uterine lining.
Some key considerations in the IVF process include:
- The number of embryos to transfer, with the guideline from 2024 1 providing recommendations on this aspect
- The use of single embryo transfer (SET) versus multiple embryo transfer, with studies such as the one from 2018 1 discussing the effectiveness and cost-effectiveness of different approaches
- The importance of monitoring and adjusting the treatment protocol as needed, with the study from 2016 1 highlighting the complexity of outcome measures in IVF trials
The most critical aspect of the IVF process is the transfer of one or more embryos into the uterus using a thin catheter, with any remaining viable embryos potentially cryopreserved for future use, as this step has the most significant impact on the success of the treatment. A pregnancy test is typically performed about two weeks after the embryo transfer. This complex process bypasses certain fertility barriers by directly bringing eggs and sperm together outside the body and placing resulting embryos into the uterus. The choice of outcome measures in IVF trials is also crucial, with live birth being a key outcome, as emphasized by the IMPRINT statement 1.
From the Research
Trial IVF Process
The process for a trial of In Vitro Fertilization (IVF) involves several steps, including:
- Diagnosis and management of infertility, which may involve identifying the cause of infertility, such as ovulatory dysfunction, male factor infertility, or tubal disease 2
- Ovulation induction with timed intercourse or ovarian stimulation using medications such as clomiphene citrate, aromatase inhibitors, or gonadotropins 2
- IVF cycle, which includes:
- Ovarian stimulation to produce multiple eggs
- Egg retrieval
- Fertilization of eggs with sperm
- Embryo transfer
- Luteal phase support to help the embryo implant in the uterus 3
- Monitoring for potential complications, such as ovarian hyperstimulation syndrome (OHSS) 4
Factors Affecting IVF Success
Several factors can affect the success rate of IVF, including:
- Age and body mass index (BMI) of the couple 5
- Serum levels of certain hormones 5
- Sperm characteristics 5
- Physical environment and genetics 5
- Psychological factors 5
- Nutrient supplementation to enhance semen quality 5
IVF Protocol
The IVF protocol may vary depending on the individual's or couple's specific needs and circumstances. Some studies have investigated the use of:
- Gonadotropin-releasing hormone agonist (GnRH-a) versus human chorionic gonadotropin (hCG) for triggering follicular maturation 3
- Minimal ovarian stimulation for IVF, which involves extending the "follicle-stimulating hormone window" combined with the GnRH antagonist cetrorelix 6
- The number of follicles ≥10 mm on the day of triggering final oocyte maturation as a predictor of severe OHSS in IVF cycles 4