Characterization of Ovarian Follicular Wave Dynamics in Women1

Abstract

A wave phenomenon of ovarian follicular development in women has recently been documented in our laboratory. The objective of the present study was to characterize follicular waves to determine whether women exhibit major and minor wave patterns of follicle development during the interovulatory interval (IOI). The ovaries of 50 women with clinically normal menstrual cycles were examined daily using transvaginal ultrasonography for one IOI. Profiles of the diameters of all follicles >or=4 mm and the numbers of follicles >or=5 mm were graphed during the IOI. Major waves were defined as those in which one follicle grew to >or=10 mm and exceeded all other follicles by >or=2 mm. Minor waves were defined as those in which follicles developed to a diameter of <10 mm and follicle dominance was not manifest. Blood samples were drawn to measure serum concentrations of estradiol-17beta, LH, and FSH. Women exhibited major and minor patterns of follicular wave dynamics during the IOI. Of the 50 women evaluated, 29/34 women with two follicle waves (85.3%) exhibited a minor-major wave pattern of follicle development and 5 women (14.7%) exhibited a major-major wave pattern. Ten of the 16 women with three follicle waves (62.5%) exhibited a minor-minor-major wave pattern, 3 women (18.8%) exhibited a minor-major-major wave pattern, and 3 women (18.8%) exhibited a major-major-major wave pattern. Documentation of major and minor follicular waves during the menstrual cycle challenges the traditional theory that a single cohort of antral follicles grows only during the follicular phase of the menstrual cycle.

Progress in understanding human ovarian folliculogenesis and its implications in assisted reproduction

“…The repeatability of wave pattern and the proportion of two-versus three-wave patterns within the herd were not influenced by the season of year [21]. Those several lines of evidence suggested that the 2 or 3 wave pattern can be repeatable almost at any estral cycle of the same individual and is related with the length of IOI, which are in high accordance with the circumstances observed in human [8,9]. Moreover, results of studies were also supportive of the hypothesis of a regulatory role of the dominant follicle of Wave 1 on the wave pattern [21].…”

“…However, the pattern of follicular wave emergence is a long-standing debate. There has been increasing evidence to suggest that multiple (two or three) antral follicular waves are recruited during the menstrual cycle [8,9]. In other words, antral follicular growth may start in different phases of the menstrual cycle due to the balance of endocrine and intra-ovarian regulators [7], which differs from what was previously thought.…”

“…Follicular development occurs in a wave-like pattern in most domesticated animal species [15][16][17] and in humans [8,9] during the estral/menstrual cycle. The decrease of luteal estradiol and inhibin A following regression of corpus luteum leads to a transient rise of serum FSH, thus, follicle recruitment is induced [18].…”

Diagnostic Criteria for Polycystic Ovary Syndrome: Pitfalls and Controversies

“…55 The cut-off of ≥ 12 follicles throughout the entire ovary was based on a single report demonstrating this value to have 99% specificity and 75% sensitivity in distinguishing between polycystic and normal ovaries. 56 The reproducibility of these values has not been confirmed in repeated studies, and there is evidence to support the postulate that these cut-off values cannot be used to distinguish between women with and without PCOS 57,58 (e.g., 58% of the control subjects in the study of Diamanti-Kandarakis et al 33 had > 12 follicles per ovary). As a result, many reproductive endocrinologists use their own criteria in clinical practice (e.g., > 20 follicles per ovary 58 or increased stroma/total area ratio 59 ), while medical imaging specialists tend to use older criteria because of the slow dissemination of findings among disciplines.…”

Age-associated changes in bovine oocytes and granulosa cell complexes collected from early antral follicles

“…Cows retain their reproductive ability for much longer than rodents, and show similar oocyte selection process and age-associated endocrinal events as that in humans [1][2][3]. Japan has a traceability system that helps researchers obtain information about the breed and day of birth of cows at any of the slaughter houses.…”