[Comparison of predictive values of inhibins A and B, and plasma estradiol in IVF patients treated with GnRH agonists and recombinant FSH]

Potential use of biomarkers for analyzing interpopulation and cross-cultural variability in reproductive aging

OBJECTIVE

The aims of this study were (1) to document the extent of variability in physiological aspects of reproductive aging; (2) to outline those areas where more work is needed to expand our knowledge of this variability; (3) to outline available biomarkers that can be used to measure aspects of reproductive aging, such as ovarian reserve and declining hormone levels; and (4) to note potential problems with the use of these biomarkers in cross-cultural settings.

DESIGN

Literature review of English and French publications using PubMed with no date restrictions.

RESULTS

Substantial variability exists in both cultural and physiological aspects of reproductive aging and menopause. However, the extent of variability across populations for many areas of reproductive aging needs better documentation as well as explanation of sources of this variability. Several biomarkers exist for use in cross-cultural research, including ovarian characteristics such as ovarian volume, ovarian reserve, follicular development, and atresia, and levels of hormones such as follicle-stimulating hormone, inhibin B, and anti-mullerian hormone.

CONCLUSION

We urge that further work be undertaken to evaluate and describe variability in physiological aspects of reproductive aging in cross-cultural settings. Some problems exist in the use of biomarkers to record this variability, particularly in remote settings with few logistical resources.

Antral follicle count, anti-mullerian hormone and inhibin B: predictors of ovarian response in assisted reproductive technology?

OBJECTIVE

The objective of this study was to evaluate the relationship between anti-mullerian hormone (AMH), inhibin B and antral follicle count (AFC) with ovarian response.

DESIGN

Retrospective study.

SETTING

Fertility unit.

SAMPLE

AFC was recorded, and a serum sample obtained on day 3 from all patients undergoing in vitro fertilisation (IVF). Patients were given 300 IU/L recombinant follicle stimulating hormone (FSH; Gonal F). The following day blood samples were collected. METHODS Serum samples were assayed for FSH, AMH and inhibin B using commercial immunoassay kits and oestradiol using an in house assay.

MAIN OUTCOME MEASURES

Response to gonadotrophin stimulation and the number of eggs collected.

RESULTS

AFC was negatively correlated to age (r=-0.426, P < 0.001). Delta inhibin B (levels of inhibin B on day 4 minus day 3) had the best association to the number of eggs collected (r= 0.533, P < 0.001) followed by basal AMH (r= 0.51, P < 0.001) and AFC (r= 0.505, P < 0.001). The number of eggs fertilised was significantly associated with basal AMH (r= 0.592, P < 0.001) and inhibin B (r= 0.548, P < 0.001). AMH with a cutoff of 0.2 ng/mL had the best sensitivity (87%) and specificity (64%) in predicting poor response. A cumulative score using basal FSH, basal AMH, delta E2 (levels of oestradiol on day 4 minus day 3), delta inhibin B, AFC and age gives the best predictive statistics to identify poor responders with 87% sensitivity and 80% specificity and a positive likelihood ratio of 4.36.

CONCLUSION

Delta inhibin B had the best positive association with the number of eggs collected and basal AMH is the single best predictor of poor response. AFC has a significant association with the number of eggs collected and is predictive of clinical pregnancy. It is evident that a single parameter is of limited value in predicting ovarian response. However, we have demonstrated a cumulative score using all the above markers could be useful in predicting poor response.

[Inhibins, activins and anti-Müllerian hormone: structure, signalling pathways, roles and predictive value in reproductive medicine]

Anti-Müllerian hormone (AMH), inhibins and activins are members of the transforming growth factor (TGFbeta) superfamily and are known to have a variety of actions concerning reproduction, hormonogenesis, development processes and differentiation. Inhibins and activins are dimeric glycoproteins that are defined by their actions on the pituitary gonadotroph cells. AMH, inhibins and activins have a vast array of actions usually exerted through paracrine and endocrine mechanisms. The recent availability of specific inhibin assays has demonstrated that inhibin B is the relevant circulating inhibin form in the human male. Inhibin B seems to be a useful marker of spermatogenesis, but serum and seminal inhibin B levels are not predictive parameters for the selection of azoospermic men as candidates for testicular sperm extraction (TESE). AMH in seminal plasma may be important for sperm production, and is a good marker for sertoli cell development. It might be the only one seminal marker of spermatogenesis in non-obstructive azoospermia. Nevertheless, many of these studies were carried out with small patient numbers, and consequently must be interpreted with caution. In women ongoing assisted reproductive therapy (ART), day 3 inhibin B and AMH levels predict the number of oocytes retrieved, but cannot predict likelihood of pregnancy. Further studies are needed to determine if AMH and inhibin predict ART outcomes better than classical parameters (age, FSH levels and follicular ultrasonography). AMH and inhibin are also specific markers of Sertoli- and granulosa-cell origin in gonadal tumors.