Inhibin B levels on cycle day 3 to predict the ovulatory response in women with PCOS undergoing ovulation induction via low dose step-up gonadotropin protocol

Can Inhibin B Reflect Ovarian Reserve of Healthy Reproductive Age Women Effectively?

OBJECTIVE

The reference range and potential value of inhibin B are still unclear and controversial. This study aimed to define the variation trend of inhibin B in healthy women with age and explore its value in the reflection of ovarian reserve.

METHODS

A total of 2524 healthy reproductive age women from eight medical institutes nationwide were recruited. The variation tendency of inhibin B with age was primarily established in the first group of 948 women and validated in another 605. We evaluated the relationship between inhibin B and classic ovarian reserve and function markers. The potency of inhibin B in predicting AFC <5-7 was also estimated and compared with FSH.

RESULTS

The nomogram showed that serum levels of inhibin B rapidly decreased after the age of 40. Inhibin B was positively correlated with AMH (R = 0.57, P < 0.001), AFC (R = 0.34, P < 0.001) and testosterone (R = 0.10, P = 0.002), and negatively correlated with FSH (R = -0.41, P < 0.001) and LH (R = -0.20, P < 0.001) and FSH/LH (R=-0.18, P < 0.001), while no correlation was found with PRL. Unexpectedly, Inhibin B (AUC = 0.74, P < 0.001 for the establishment population; AUC = 0.78, P < 0.001 for the validation population) had a slightly higher value than FSH (AUC = 0.71, P < 0.001 for the establishment population; AUC = 0.72, P < 0.001 for the validation population) in diagnosing AFC <5-7.

CONCLUSIONS

For healthy reproductive age women, the decline of inhibin B can reflect decreased ovarian reserve effectively, having a good consistency with AMH and AFC. More importantly, inhibin B had an advantage in predicting AFC <5-7 compared with FSH, which suggested the potential of inhibin B in predicting ovarian response. These results will be helpful to the clinical application of inhibin B in the evaluation of female ovarian reserve and the assessment of their reproductive capacity. Trial registration: http://clinicaltrials.gov; NCT02294500.

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

OBJECTIVE

To describe changes of anti-Müllerian hormone (AMH) and inhibin B during low-dose gonadotropin ovulation induction (OI) treatment in women with polycystic ovary syndrome (PCOS), and thus disturbed selection of the dominant follicle.

DESIGN

Observational study.

SETTING

A referral fertility clinic.

PATIENT(S)

Women with PCOS (n = 48) and normo-ovulatory women (n = 23).

INTERVENTION(S) AND MAIN OUTCOME MEASURE(S)

Serum AMH, inhibin B, FSH, and E(2) concentrations were measured at start of stimulation, on the day of follicle selection, and at administration of hCG during OI cycles and were compared with concentration measured during the normal menstrual cycle.

RESULT(S)

Development of a single dominant follicle was observed in 92% of all OI cycles, reflected by similar E(2) concentrations compared with those in spontaneous cycles. AMH concentrations were constant during low-dose ovarian stimulation. Inhibin B concentrations remained elevated in patients with PCOS, suggesting prolonged survival of small antral follicles, whereas in controls inhibin B concentrations declined during the late follicular phase.

CONCLUSION(S)

The lack of change in AMH and inhibin B concentrations suggest that follicle dynamics during low-dose stimulation seem different from those during controlled ovarian hyperstimulation. In addition, constant AMH and inhibin B levels suggest that neither AMH nor inhibin B is an accurate marker of ovarian response after low-dose gonadotropin OI in patients with PCOS.

Do basal inhibin A and inhibin B levels have value in the diagnosis of polycystic ovary syndrome?

In the present study we aimed to investigate whether basal inhibin A and B levels in women with polycystic ovary syndrome (PCOS) would be used in diagnosis of the condition. Forty women with PCOS and 40 women with normal cycles (control group) were evaluated. There was no statistically significant difference in mean age and mean body mass index between the two groups (p > 0.05). Serum levels of inhibin A and B, follicle-stimulating hormone (FSH), luteinizing hormone and total testosterone, and total ovarian volume, were determined in the PCOS group and the control group on day 3. In the PCOS group, total follicle number was obtained by counting follicles of diameter > or =2 mm in both ovaries. Results were evaluated using Student's t test, Pearson correlation and regression tests. There was no significant difference in mean basal inhibin A or inhibin B levels between the two groups. Basal inhibin B levels showed a statistically significant negative correlation with basal FSH levels and a positive correlation with total follicle number in the PCOS group (p < 0.05 and p < 0.01, respectively). We conclude that basal inhibin A or B levels cannot be used in the diagnosis of PCOS.