Definition - What does Ovarian Stimulation mean?
Ovarian stimulation is when medications are used to develop and mature eggs in order to boost the odds of a successful pregnancy in women having difficulty getting pregnant. This can include inducing ovulation in women who do not have a regular menstrual cycle or ovarian hyperstimulation where the aim is to mature multiple eggs from the ovaries as part of intrauterine insemination or in vitro fertilization.
Ovarian stimulation is also referred to as controlled ovarian stimulation (COH).
FertilitySmarts explains Ovarian Stimulation
During the ovarian stimulation phase, the specialist will schedule several visits. Instead of “one size fits all,” the treatment protocol is customized depending on a few factors, most importantly, a woman’s ovarian reserve (i.e. the number of eggs in a woman’s ovary).
Ovarian stimulation involves injecting the fertility medications for around 8-14 days, to induce the ovaries to create many eggs. For this, different stimulation protocols using hormones like follicle-stimulating hormone (FSH) in combination with gonadotropin-releasing hormone (GnRH) are employed.
FSH, as the name implies, stimulates follicles (small fluid-filled cysts) to develop within the ovaries. In a normal menstrual cycle, several follicles crop up, but as the FSH levels fall, all the follicles die off and only one matures to become a dominant follicle and release the egg. The goal of injecting FSH is thus to maintain higher levels of FSH in a woman’s system, enabling the ovaries to produce as many mature eggs as possible.
After the maturation of the follicles and just before ovulation, a large dose of hCG “trigger shot” is used to trigger the “LH (luteinizing hormone) surge” to induce ovulation and release eggs for retrieval or insemination. This usually takes place at about 36 to 48 hours after the trigger shot.
During the stimulation phase, regular blood tests will be done to measure the hormonal levels in the body, and to assess how well the patient is responding to fertility medications. Not all women respond to IVF medications equally. Hence, the fertility specialist will adjust the medication dose to ensure the production and yield of multiple mature follicles, and at the same time take care not to exceed the recommended maximum dose to minimize the risk of ovarian hyperstimulation syndrome (OHSS).