Long & Short IVF protocols remain the most commonly used stimulation protocols and in the Long Protocol Lupron (a birth control pill) is used to control the menstrual cycle and prevent ovulation. Stimulation comes from either follicle stimulating hormone (FSH) or human menopausal gonadotropin (hMG), with an injection of human chorionic gonadotropin (hCG) before egg collection to mature the eggs.
After egg collection progesterone is given to mature the lining of the womb for implantation and to maintain the pregnancy when there’s a positive pregnancy test.
The whole cycle usually takes 6 weeks:
- 3-4 weeks of birth control pills (it allows for scheduling at the clinic)
- Five days before the end of the end of this the ovaries are ‘down regulated’ for 2 weeks with Lupron (a GnRH agonist) which ‘switches’ the menstrual cycle off. The advantages of this are a higher response to stimulation and reduced risk of ovarian hyper-stimulation syndrome (OHSS)
- A period
- This is followed by daily stimulation injections for about 8-12 days with FSH or hMG
- The ovaries are usually scanned every 2 -3 days until the leading follicle is over 18mm in diameter and the womb lining is over 8mm thick
- Blood samples are taken to monitor estrogen levels
- When the follicles reach a mature size a “trigger injection” of hCG induces the eggs to undergo the final maturation and detach from the follicle wall
- An injection of GnRH antagonist can be given 36 hours before egg collection to prevent follicles rupturing prematurely (it also helps to mature the follicles)
- The eggs are collected, fertilized and incubated
- Progesterone pessaries are taken after the eggs are collected
- Embryo transfer is usually 3-5 days after egg collection
Stimulated short-treatment protocol
This is a 4-week-cycle protocol, without the GnRH down-regulation and is usually used when there’s been a poor response to a long protocol, or for women with low ovarian reserve.
- Treatment starts with FSH or hMG stimulation on day 3 of the cycle (day 1 being the first day of the period) and lasts for around 11 days
- The ovaries are usually scanned every 2 -3 days until the diameter of the leading follicle is over 18mm and the womb lining is over 8mm thick and blood estrogen levels are also monitored
- An hCG “trigger injection” is given to make the eggs undergo their final maturation and detach from the walls of the follicles
- A GnRH antagonist is injected 36 hours before egg collection to prevent premature ovulation and to help the eggs fully mature
- The eggs are collected, fertilised and incubated in the laboratory
- Progesterone pessaries are taken once the eggs are collected
- Embryo transfer is usually 3-5 days later