What is the IVF Antagonist Protocol?
During the IVF journey, several medication protocols are designed to stimulate the ovaries to produce multiple mature eggs for retrieval and fertilization in a laboratory. The antagonist, or “short” protocol, is the most common protocol. In this article, we will outline the antagonist protocol, including the medications you will use, how they work, and a treatment timeline.
What is the Antagonist IVF Protocol?
The Antagonist protocol is a medication regimen for IVF that uses injectable FSH (Follicle Stimulating Hormone) to stimulate egg development along with GnRH “Antagonists,” which prevent ovulation so that the eggs can be surgically retrieved at the optimal time.
The more fully mature eggs that are retrieved, the higher the likelihood of creating viable embryos that can be transferred back into the uterus and frozen for future transfer (FET).
What Medications Are Used in the Antagonist Protocol?
The most common medications used in the antagonist protocol to prevent premature ovulation are Ganirelix acetate and Cetrotide.
As gonadotropin-releasing hormone (GnRH) antagonists, these medications competitively bind to GnRH receptors in the pituitary gland. Doing so suppresses the body’s natural secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), thereby preventing the LH surge that causes eggs to be released from the ovaries (ovulation).
Antagonist Protocol Timeline
The following is an example of a standard antagonist protocol timeline:
- 10 days of FSH (Follicle Stimulating Hormone).
- Daily administration of antagonist medication along with FSH days 6-10.
- Between day 10-12, you will take either hCG, a high dose of Lupron, or a combination of both to trigger oocyte maturation.
Keep in mind that the exact number of days required for each medication will depend on how your body responds to the medications (your follicular/egg development).
Though HCG and Lupron work well to trigger egg maturation, Lupron can significantly decrease the risk of Ovarian Hyperstimulation Syndrome (OHSS).
Antagonist Protocol Calendar
Down Regulation Agonist
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Below is a standard Antagonist IVF calendar. The calendar sets day one to the day medications are started (which is usually days 2-4 of a female’s menstrual cycle). Each phase of an IVF is inherently variable and will be customized specifically for you.
Below is a standard Mini IVF calendar. The calendar sets day one to the day medications are started (which is usually days 2-4 of a female’s menstrual cycle). Each phase of an IVF is inherently variable and will be customized specifically for you.
Below is a standard Down Regulation Agonist IVF calendar. Down Regulation protocols are uncommon but may be suggested by your provider based on your specific history. Each phase of an IVF is inherently variable and will be customized specifically for you.
Below is a standard FET calendar. The calendar sets day one to the day medications are started (which is usually days 2-4 of a female’s menstrual cycle). Each phase of an FET is inherently variable and will be customized specifically for you.
Below is a standard Egg Freezing calendar. The calendar sets day one to the day medications are started (which is usually days 2-4 of a female’s menstrual cycle). Each phase of an Egg Freezing is inherently variable and will be customized specifically for you.
Progesterone Start Day
- 30-90 DAYS PRIOR TO TREATMENT CYCLE Kiltz’s Keto/Carnivore, OMAD Supplements ( F: Peak Prenatal, VIVOMEGA, Ovarian Bloom, Immunoglobulin IgG | M: Male Preconception+, VIVOMEGA ) LDN (by prescription only after consultation) HGH Humira (1 time two weeks prior to start of cycle)
Day {{day}}
- Office Visit: {{get_office_visit(day)}}
- FSH {{ is_FSH_start(day) ? "start" : "" }} {{ is_FSH_end(day) ? "end" : "" }}
- Lupron {{ is_lupron_start(day) ? "start" : "" }} {{ is_lupron_end(day) ? "end" : "" }}
- Letrozole {{ is_letrozole_start(day) ? "start" : "" }} {{ is_letrozole_end(day) ? "end" : "" }}
- hMG {{ is_hMG_start(day) ? "start" : "" }} {{ is_hMG_end(day) ? "end" : "" }}
- hCG+LH {{ is_hCG_start(day) ? "start" : "" }} {{ is_hCG_end(day) ? "end" : "" }}
- Antagonist {{ is_antagonist_start(day) ? "start" : "" }} {{ is_antagonist_end(day) ? "end" : "" }}
- {{get_lupron_label()}} {{ is_trigger_lupron_start(day) ? "start" : "" }} {{ is_trigger_lupron_end(day) ? "end" : "" }}
- hCG {{ is_trigger_hcg_start(day) ? "Take" : "" }}
- Procedure Day: Egg Retrieval
- Procedure Day: {{transfer_selected}}
- Pregnancy Test
- Estrogen, Progesterone
- Estrogen
- Progesterone
- {{get_level_1(day).join(", ")}}
- {{get_level_2(day).join(", ")}}
- {{get_level_3(day).join(", ")}}
- {{get_level_4(day).join(", ")}}
- {{tooltip}}
Day {{day}}
- Office Visit: {{get_office_visit(day)}}
- FSH {{ is_FSH_start(day) ? "start" : "" }} {{ is_FSH_end(day) ? "end" : "" }}
- Lupron {{ is_lupron_start(day) ? "start" : "" }} {{ is_lupron_end(day) ? "end" : "" }}
- Letrozole {{ is_letrozole_start(day) ? "start" : "" }} {{ is_letrozole_end(day) ? "end" : "" }}
- hMG {{ is_hMG_start(day) ? "start" : "" }} {{ is_hMG_end(day) ? "end" : "" }}
- hCG+LH {{ is_hCG_start(day) ? "start" : "" }} {{ is_hCG_end(day) ? "end" : "" }}
- Antagonist {{ is_antagonist_start(day) ? "start" : "" }} {{ is_antagonist_end(day) ? "end" : "" }}
- {{get_lupron_label()}} {{ is_trigger_lupron_start(day) ? "start" : "" }} {{ is_trigger_lupron_end(day) ? "end" : "" }}
- hCG {{ is_trigger_hcg_start(day) ? "Take" : "" }}
- Procedure Day: Egg Retrieval
- Procedure Day: {{transfer_selected}}
- Pregnancy Test
- Estrogen, Progesterone
- Estrogen
- Progesterone
- {{get_level_1(day).join(", ")}}
- {{get_level_2(day).join(", ")}}
- {{get_level_3(day).join(", ")}}
- {{get_level_4(day).join(", ")}}
- {{tooltip}}
Day {{day}}
- Office Visit: {{get_office_visit(day)}}
- FSH {{ is_FSH_start(day) ? "start" : "" }} {{ is_FSH_end(day) ? "end" : "" }}
- Lupron {{ is_lupron_start(day) ? "start" : "" }} {{ is_lupron_end(day) ? "end" : "" }}
- Letrozole {{ is_letrozole_start(day) ? "start" : "" }} {{ is_letrozole_end(day) ? "end" : "" }}
- hMG {{ is_hMG_start(day) ? "start" : "" }} {{ is_hMG_end(day) ? "end" : "" }}
- hCG+LH {{ is_hCG_start(day) ? "start" : "" }} {{ is_hCG_end(day) ? "end" : "" }}
- Antagonist {{ is_antagonist_start(day) ? "start" : "" }} {{ is_antagonist_end(day) ? "end" : "" }}
- {{get_lupron_label()}} {{ is_trigger_lupron_start(day) ? "start" : "" }} {{ is_trigger_lupron_end(day) ? "end" : "" }}
- hCG {{ is_trigger_hcg_start(day) ? "Take" : "" }}
- Procedure Day: Egg Retrieval
- Procedure Day: {{transfer_selected}}
- Pregnancy Test
- Estrogen, Progesterone
- Estrogen
- Progesterone
- {{get_level_1(day).join(", ")}}
- {{get_level_2(day).join(", ")}}
- {{get_level_3(day).join(", ")}}
- {{get_level_4(day).join(", ")}}
- {{tooltip}}
- Standard Medications
- Office Visit
- Procedure Day
- Enhancement/Immune Protocol Medications
How Effective is the Antagonist Protocol?
The Antagonist protocol is considered by the majority of fertility experts to be the most effective IVF protocol.
GnRH Antagonists are highly effective in preventing premature ovulation, require less time and fewer injections than alternative methods of preventing ovulation, and help reduce the risk of Ovarian Hyper Stimulation (OHSS).
Advantages of the Antagonist Protocol
Here is a rundown of the various advantages of an antagonist IVF protocol:
- Precision ovarian stimulation control: GnRH antagonists immediately halt LH secretion, supporting synchronization of follicular development.
- Shortens treatment duration: GnRH antagonists decrease treatment cycles by 7-14 days compared to agonist protocols.
- Reduced number of injections and a simplified IVF process.
- Reduces risk of Ovarian Hyperstimulation Syndrome (OHSS): By providing more controlled hormone levels, GnRH antagonists reduce the likelihood of developing OHSS.
- Increases flexibility in IVF: The instantaneous effects of antagonist medications allow fertility specialists to adjust treatment protocols based on the patient’s response to stimulation, potentially leading to better outcomes.
- Antagonists are especially beneficial for high responders. Antagonist medications lower the risk for OHSS by suppressing LH more than agonist medications.
- Allows for the use of Lupron to trigger egg maturation prior to egg retrieval. Lupron is better tolerated than hCG, and can virtually eliminate the risk of OHSS.
Other IVF Protocols
Though the antagonist protocol is the standard and most common form of treatment, there are a few other protocols to be aware of, including:
- Agonist (Long) Protocol: Uses Lupron to suppress the pituitary gland’s normal production of hormones, essentially preventing/delaying ovulation.
- The Flare, or Lupron Microdose Protocol: Same as the agonist protocol but Lupron is administered at a lower dose and in conjunction with gonadotropins.
- Mini IVF: Highly variable in terms of the exact medication regimen used across clinics. At CNY Fertility, the same medications and timeline as standard antagonist protocol are used with the addition of Letrozole for 5 days and lower doses of FSH.
- Estrogen priming: Taking birth control or estrogen pills over days or weeks leading up to treatment to control/schedule the timing of the IVF cycle.
- Immune Protocols: An add-on protocol that can involve the use of various immunosuppressant medications to prepare the body for embryo transfer and enhance the chances of successful implantation.
The Antagonist IVF Protocol: The Bottom Line
The antagonist IVF protocol offers a streamlined and effective approach to fertility treatment, making it the most widely used method. With its shorter treatment duration, reduced risk of ovarian hyperstimulation, and flexibility in managing ovarian stimulation, it is well-suited for nearly all patients.
