When beginning an IVF cycle, the ultimate goal of our team is to enable the patient to take home a healthy baby while minimizing the risk of multiples. New advances in laboratory techniques have made it possible to achieve this. Assisted reproductive technologies also include Intracytoplasmic sperm injection, Blastocyst culture, assisted hatching and cryopreservation.
The most commonly used protocol for IVF involves giving a drug called gonadotropin releasing hormone analogue by daily injection e.g. busereline, lupron or a long-acting injection such as zoladex The logic behind giving the agonist is to temporarily suppress the woman’s natural hormones (down-regulation) and allows for greater control over the treatment cycle. There are different protocols for administering these drugs; each has its pros and cons.
Currently, the long protocol is preferred because it is more convenient and has shown superior efficacy.
In the long protocol the agonist is usually started around day 21 of the cycle preceding IVF cycle .sitmulation will be started from 1st or2nd day of cycle. Symptoms such as hot flushes, headaches, mood changes and night sweats may be noticed. These symptoms usually last for a relatively short period of time and will usually disappear once the hormonal injections have started.
Approximately two weeks after the start of GnRh agonist a vaginal ultrasound scan will be performed to ensure that the ovaries are inactive and that the lining of the womb is thin. A blood test may also be required to estimate the hormone levels in order to ensure down regulation.
After achieving “down regulation” it is common to be advised to continue to take GnRh agonist but to reduce the dose to maintenance and to begin to take gonadotropin injections such as FSH and or hMG injections to stimulate the ovaries . The initial dosage of the injections will be chosen to suit each individual. The injections are usually given once a day for about 10-12 days. The dose of the gonadotropin is adjusted later depending on the response. The use of gonadotropin releasing hormone antagonists may allow for shorter treatment cycles and lower doses of gonadotropin injections but are associated with lower pregnancy rates. Urine derived purified gonadotropins and recombinant FSH are equally effective when used with down-regulation.
When Should a GnRH Antagonist Be Started for Optimal IVF Cycle Outcome?
GnRH antagonists are usually started on day 6 of stimulation or once the lead follicle reaches a certain size. Ludwig (Department of Gynecology and Obstetrics, Medical University of Lubeck, Lubeck, Germany) and associates tried to determine which was associated with the better outcome: cetrorelix 0.25 mg daily initiated on day 6, or cetrorelix 0.25 mg daily initiated when the lead follicle was 14 mm. In a third group, the patients received a 1-time injection of 3 mg cetrorelix when the lead follicle was 14 mm. The researchers found that cycles during which 0.25 mg cetrorelix was started when the lead follicle was 14 mm were associated with the lowest gonadotropin need. On average, more oocytes were retrieved when the antagonist was started in an individualized way. The number of patients enrolled was too small to evaluate pregnancy outcome.