Related Experiment Video
Updated: Sep 28, 2026

Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
Induction of multiple follicular growth in normally menstruating women with endogenous gonadotropin suppression
Abstract:
Patients with normal menstrual rhythm and normal luteinizing hormone were treated with exogenous gonadotropins to induce multiple follicular development. This was effected in the absence (34 cycles in 12 patients) or with concurrent suppression of endogenous gonadotropin levels with a gonadotropin-releasing hormone analog (84 cycles in 18 patients). In the absence of the analog, "premature" luteinization occurred in 51% of cycles before the ultrasonic visualization of a follicle with a diameter of 20 mm. In the analog-treated cycles, premature luteinization was almost totally eliminated and progesterone elevations were delayed until after administration of human chorionic gonadotropin. Follicular estrogen production was unaffected by the analog treatment, compared with hypogonadal patients treated with exogenous gonadotropins. The characteristics of follicular development showed that two to three follicles of mature size were induced with this technique, and the capacity for the induction of a larger number of follicles was evident.
Related Concept Videos
Oogenesis
Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
Ovarian Cycle
Folliculogenesis
Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Proliferative Phase
Notably, the stratum basale, the basal layer of the endometrium, including the basal parts of the uterine glands, remains unaffected by menstruation. Stem cells in this layer undergo mitosis, regenerating the stratum functionalis and thickening the...

