Relationship between inhibin A and B, estradiol and follicle growth dynamics during ovarian stimulation in normo-ovulatory women

Abstract

Objective: To investigate the relationship between serum concentrations of inhibin A, inhibin B and estradiol (E 2 ) and the number of developing follicles during the administration of exogenous follicle-stimulating hormone (FSH) in various regimens in normo-ovulatory volunteers and to evaluate if inhibins act as suitable markers for the number of developing follicles during ovarian stimulation. Design and methods: Serial hormone determinations and assessment of follicle numbers were carried out during unstimulated cycles and during various interventions with exogenous FSH. Subjects were randomized for FSH administration into the following groups: a single high dose (375 IU) during the early follicular phase (group A), 5 consecutive low doses (75 IU/day) starting in the mid follicular phase (group B) or daily low doses (75 IU/day) during the early to late follicular phase (starting on cycle days 3, 5 or 7; groups C, D and E respectively). Results: Extending the FSH window increases the number of small antral follicles and hence inhibin B serum concentrations. If such an intervention results in multi-follicular growth, mid follicular phase inhibin B (P ¼ 0.001) as well as late follicular phase inhibin B and inhibin A levels are significantly (P , 0.05 and P , 0.01 respectively) increased compared with mono-follicular cycles or the natural cycle. Although mid follicular inhibin B levels correlated well with the number of small antral (P , 0.05) and pre-ovulatory (P , 0.001) follicles in the late follicular phase, mid follicular inhibin A and estradiol serum concentrations only correlated with the number of pre-ovulatory follicles (P , 0.001 and P , 0.01 respectively). Conclusions: The present data extend our understanding of the relationship between follicle dynamics, serum inhibins and FSH during ovarian hyperstimulation. However, although mid follicular inhibin B does correlate with the number of developing follicles, it does not facilitate the identification of women at risk for multiple follicle development.European Journal of Endocrinology 152 395-401

Dynamics of early estradiol production may be associated with outcomes of in vitro fertilization

“…No significant correlations were observed between the studied dynamic variables and pregnancy outcomes. This finding was consistent with earlier reports (5)(6)(7)(8).…”

“…Eldar-Geva et al (7) suggested that luteal phase E 2 with GnRH agonist long protocol is higher in high responders than in normal or poor responders. Hohmann et al (8) revealed that mid-and latefollicular phase levels of E 2 during ovarian stimulation without GnRH analogue were positively correlated with the number of follicles of different size categories in the late follicular phase. The present study was conducted in GnRH antagonist cycles, which differentiates it from earlier studies.…”

Pharmacokinetics and follicular dynamics of corifollitropin alfa versus recombinant FSH during ovarian stimulation for IVF

“…In addition, the differences were observed in the number of follicles <17 mm, which contribute less to the serum concentrations of oestradiol (Bomsel-Helmreich et al, 1979;van Dessel et al, 1996). However follicles <11 mm contribute more to circulating concentrations of inhibin B (Hohmann et al, 2005;Wen et al, 2006).…”

Serum anti-Müllerian hormone and inhibin B concentrations are not useful predictors of ovarian response during ovulation induction treatment with recombinant follicle-stimulating hormone in women with polycystic ovary syndrome

“…Indeed, it widely is considered that selection of the dominant follicle is impaired in women with PCOS, because of failure of FSH-dependent follicle recruitment (26). Apparently, by administration of a small amount of exogenous FSH, the ''blocked'' cyclic recruitment in women with PCOS can be overruled and multiple follicles surpass the FSH threshold (27). Despite this prolonged survival of follicles with continuous low-dose FSH administration after cyclic recruitment, development of a single dominant follicle was unaffected in the majority of treated PCOS subjects, as reflected by mono-ovulation.…”