Circulating inhibins and activin A during GnRH-analogue down-regulation and ovarian hyperstimulation with recombinant FSH for in-vitro fertilization-embryo transfer

Clin Endocrinol (Oxf). 1996 Dec;45(6):741-8. doi: 10.1046/j.1365-2265.1996.8510861.x.


Objective: We have investigated serial changes in plasma concentrations of inhibin A, inhibin B, pro alpha C and activin A in women undergoing stimulation with recombinant FSH in 'long-protocol' down-regulated cycles of IVF treatment.

Design: Blood samples were collected during the entire IVF treatment cycle at points coinciding with the early follicular phase of the cycle preceding treatment, pituitary down-regulation, stimulation with recombinant FSH, ovulatory triggering, and the luteal phase of the cycle. In patients who achieved conception, blood samples were also taken during the first 2 weeks of pregnancy. All samples were analysed for inhibin A, inhibin B, pro alpha C, activin A and oestradiol.

Patients: Fifteen women with normal ovarian function undergoing IVF treatment with tubal factor, mild endometriosis or idiopathic infertility.

Results: During pituitary desensitization, both inhibin A and inhibin B were significantly (P < 0.001, P = 0.002, respectively) reduced whereas levels of pro alpha C and activin A were largely unaltered. Levels of both inhibins rose markedly (P < 0.01) during FSH stimulation and a further rise in inhibin A was detected on the day after ovulatory trigger. Levels of both inhibin A and inhibin B then fell during and after oocyte pickup and continued to fall during the luteal phase. Activin A levels rose less markedly during gonadotrophin stimulation. Statistical analysis showed a high degree of correlation between the number of follicles (> 10 mm) and serum inhibin A (r = 0.65, P < 0.01) and pro alpha C (r = 0.65, P < 0.01) concentrations during the late follicular phase.

Conclusions: These results indicate that ovarian production of dimeric inhibin A and B are gonadotrophin dependent, whereas activin A may have a significant gonadotrophin independent or extra-gonadal source. Inhibin A and pro alpha C may be useful markers for monitoring the effects of gonadotrophin stimulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activins
  • Adult
  • Buserelin / administration & dosage
  • Down-Regulation
  • Embryo Transfer*
  • Female
  • Fertilization in Vitro*
  • Follicle Stimulating Hormone / administration & dosage*
  • Gonadotropin-Releasing Hormone / analogs & derivatives
  • Humans
  • Inhibins / blood*
  • Ovary / drug effects*
  • Peptides / blood*
  • Pituitary Gland / drug effects
  • Prostatic Secretory Proteins*
  • Recombinant Proteins / administration & dosage
  • Stimulation, Chemical


  • Peptides
  • Prostatic Secretory Proteins
  • Recombinant Proteins
  • beta-microseminoprotein
  • inhibin-alpha subunit
  • Activins
  • Gonadotropin-Releasing Hormone
  • Inhibins
  • Follicle Stimulating Hormone
  • Buserelin