Ovarian stimulation is an important phase of in vitro fertilization (IVF) treatments. The harvest of a larger number of viable eggs per cycle compensate eventual laboratory difficulties and allow for the selection of embryos with higher implantation potential. In the current protocols, based on the most prevailing theory of ovarian follicular development, stimulation drugs are usually started on the second or third day after the beginning of menses. The follicular phase of the menstrual cycle is believed to be the only favorable moment for follicular development. In the early 2000's a new model of human ovarian follicular development (follicular waves) has been proposed based on frequent transvaginal ultrasound observations between two ovulations. It has been shown that ovarian antral follicles develop in synchronous groups, two to three times in a cycle. In fact the follicular wave phenomenon has been initially described in the 80's on domestic animals, like the mare and the cow. Moreover, studies in these animals have shown that synchronizing the start of the ovarian stimulation drugs with the beginning of a follicular wave yields better results for assisted reproductive treatments. Consequently in ovarian stimulation protocols for animal assisted reproduction it is important to control the initiation of a follicular wave. Current protocols of ovarian stimulation for IVF in women do not consider the start of a follicular wave to begin drug administration. Therefore the purpose of this study is to evaluate two methods to control the emergence of a follicular wave (ovulation induction and dominant follicle aspiration) and to investigate the effects of synchronizing ovarian stimulation for IVF with follicular wave emergence in women compared to one of the current stimulation protocols (flexible GnRH protocol).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
30
Administration of 250 micrograms of choriogonadotropin alfa subcutaneously when the dominant follicle of a natural menstrual cycle reaches 16mm or more of mean diameter. Verify if this intervention is able to induce follicular wave emergence and synchronize the start of the flexible GnRH antagonist protocol of ovarian stimulation with the start of a follicular wave.
Aspiration of all follicles greater than 10mm in mean diameter when the dominant follicle of a natural menstrual cycle reaches 16mm or more of mean diameter. Aspiration will be guided by transvaginal ultrasound. Verify if this intervention is able to induce follicular wave emergence and synchronize the start of the flexible GnRH antagonist protocol of ovarian stimulation with the start of a follicular wave.
Conventional flexible GnRH antagonist protocol of ovarian stimulation for in vitro fertilization, with gonadotropin star at the third day of a natural menstrual cycle.
University of Sao Paulo General Hospital
São Paulo, São Paulo, Brazil
RECRUITINGEmergence of an ovarian follicular wave after dominant follicle aspiration or hCG administration
Evaluate if the aspiration of the dominant follicle is able to induce a follicular wave to emerge. Evaluate if administration of hCG is able to induce ovulation of a dominant follicle larger than 16mm and to induce a follicular wave to emerge. A follicular wave emergence is defined as an increase in the number of ovarian follicles smaller than 10mm seen at the transvaginal ultrasound scan after the interventions
Time frame: One year
Follicular growth pattern on ultrasound scan
Evaluate with periodic transvaginal ultrasound scan the size (mm), number and growth rate (mm/day) of ovarian follicles in each of the three groups
Time frame: One year
Estradiol and progesterone levels during ovarian stimulation
Evaluate blood levels of estradiol (pg/mL) and progesterone (ng/mL) during ovarian stimulation in each of the three groups at each visit to evaluate the progress of treatment.
Time frame: One year
Number of mature oocytes retrieved
Evaluate the number of metaphase II oocytes retrieved in each of the three groups
Time frame: One year
Total dose of gonadotrophins used
Total dose of gonadotrophins (in international units) necessary to stimulate the ovaries (from the first day of stimulation until the last dose of recombinant FSH administered before the oocyte retrieval)
Time frame: One year
Fertilization rate
Number of embryos formed in relation with the number of oocytes inseminated
Time frame: One year
Pregnancy rate
Positive beta hCG determination on blood 10 days after embryo transfer
Time frame: One year
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