Use of serum inhibin B levels at the start of ovarian stimulation and at oocyte pickup in the prediction of assisted reproduction treatment outcome

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.

Inhibin A-A Promising Predictive Parameter for Determination of Final Oocyte Maturation in Ovarian Stimulation for IVF/ICSI

The number of mature oocytes is a key factor in the success of Assisted Reproductive Techniques (ART). Exogenous gonadotropins are administered during ovarian stimulation in order to maximize the number of oocytes available for fertilization. During stimulation, monitoring is mandatory to evaluate individual response, to avoid treatment complications and assist in the determination of the optimal day for final oocyte maturation and oocyte retrieval. Routine monitoring during stimulation includes transvaginal ultrasound examinations and measurement of serum estradiol (E2). Due to multifollicular growth of follicles of varying size, serum E2 levels are commonly supraphysiological and often variable, rendering E2-measurement during ovarian stimulation unreliable as a determinant of oocyte maturity. In contrast to serum E2, serum Inhibin A levels increase once a minimum follicle size of 12-15 mm is achieved. Due to this fact, serum Inhibin A levels could present in combination with ultrasound monitoring a more reliable parameter to determine the optimal follicle size for final oocyte maturation, as only follicles with a size of 12 mm and beyond will contribute to the serum Inhibin A level. This prospective observational, cross-sectional study demonstrates, that on the day of final oocyte maturation serum Inhibin A is strongly correlated to the number of follicles ≥15 mm (0.72) and to the number of retrieved and mature oocytes (ρ 0.82/0.77, respectively), whereas serum E2 is moderately correlated to the parameters mentioned above (ρ 0.64/0.69/0.69, respectively). With an area under the curve (AUC) of 0.91 for Inhibin A, compared to an AUC of 0.84 for E2, Inhibin A can be regarded as a better predictor for the optimal timing of trigger medication with a threshold number of ≥10 mature oocytes. It can be concluded from this data that serum Inhibin A in combination with transvaginal ultrasound monitoring may be a more powerful tool in the decision making process on trigger timing as compared to E2.

Hyperstimulation syndrome: the levels of inhibin A and B in sera and follicular fluids

Ovarial hyperstimulation syndrome (OHSS) represents a serious problem encountered during in vitro fertilization (IVF). We examined 10 patients with OHSS and 50 women also hormonally stimulated in the process of IVF who had no complications. In all women, we evaluated the number of obtained oocytes and the level of inhibins A and B in sera and follicular fluid collected at the time of ovarial puncture, the day embryo transfer and on the day of positivity for hCG. The level of inhibin B in both fluids was significantly higher (t = 0.0403) in women with high quality of oocytes. The higher level of inhibin A was detected in patients with OHSS at the time of oocyte collection and on the day of embryo transfer. Inhibin B was elevated only at the time of oocyte collection. The levels of inhibin A and B were identical in follicular fluids collected from both ovaries. We observed no statistically significant differences between the levels of inhibin A and B in follicular fluids of women in the absence of OHSS. Evaluation of serum levels of inhibin A and B at the time of oocyte collection may contribute to the prognosis and prevention of OHSS.

Anti-Mullerian hormone dynamics during controlled ovarian hyperstimulation and optimal timing of measurement for outcome prediction

BACKGROUND

Anti-Müllerian hormone (AMH) has been suggested as a marker of ovarian reserve and predictor of ovarian response to controlled ovarian hyperstimulation (COH). Several studies have demonstrated AMH changes during follicular and luteal phases during COH, but not after human chorionic gonadotrophin (hCG) administration. The objectives of this study were to investigate changes in AMH levels during the entire COH cycle and to clarify the regulatory mechanism of AMH secretion. In addition, we analyzed the COH outcome parameters to determine the optimal timing for AMH measurement to predict outcome.

METHODS

The study included 74 women who underwent in vitro fertilization (IVF) cycles with a GnRH agonist or antagonist protocol. Serum AMH and inhibin B levels were measured at baseline, Day 5 of stimulation (d5), day of hCG administration (dhCG), day of oocyte retrieval (dOPU) and 14 days after oocyte retrieval (dPO14). Follicular fluid (FF) from dominant follicles upon oocyte retrieval were also analyzed for AMH and inhibin B concentrations. AMH levels were analyzed for changes during the cycle and for correlations with COH outcome parameters.

RESULTS

Serum AMH levels decreased progressively during COH until dhCG, then increased on dOPU and further increased on dPO14. Serum and FF AMH levels and dynamic changes were not different between the GnRH agonist and antagonist cycles. Serum AMH levels on every sample day and the FF AMH levels were significantly correlated with outcomes of COH, such as dose of gonadotrophins used, estradiol level on dhCG and number of retrieved oocytes; the strength of the relationship was highest for baseline AMH.

CONCLUSIONS

The results of the present study suggest that changes in the hormonal milieu during stimulation and after the LH surge may affect AMH secretion. Serum AMH levels during COH are good markers to predict ovarian response, but the baseline serum level seems to be the most predictive marker.

Development of a second generation Inhibin B ELISA

Inhibins are heterodimeric protein hormones secreted by the granulosa cells of the ovary in the female and the Sertoli cells of the testis in the male. Published research studies have assessed Inhibin B levels in Sertoli cell function, ovarian reserve and granulosa cell tumors. A two-step sandwich-type enzymatic microplate assay to measure Inhibin B levels within 3.5h is reported, and sample pre-treatment is not required. The assay measures Inhibin B in 50 μL of serum or Li-Hep plasma sample against Inhibin B calibrators (10-1000 pg/mL). The highly characterized antibody pair used in the assay measures 100% Inhibin B and no response was detected above the sensitivity of the assay with Inhibin A, Activin A, Activin B, Activin AB, AMH, FSH, LH or Follistatin 315 at the concentrations tested. The second generation Inhibin B assay was compared against two commercially available assays using 60 male and 60 female samples, ranging in age from 20 to 50 years. The assay showed significant positive linear correlations to Oxford Brooks Innovation (OBI) and Diagnostics Systems Laboratories (DSL) assays (r=0.99; P<0.0001; and r=0.97; P<0.0001), respectively. Method comparison to OBI and DSL resulted in the following slope and intercept (Gen II=1.03 OBI-6.77 pg/mL and Gen II=1.57 DSL+11.29 pg/mL), respectively. Matched serum and Li-Hep plasma samples (n=120) showed a correlation coefficient of >0.99 and a slope of 0.97 with zero intercept. Total imprecision calculated on three samples and two controls over 40 runs, three replicates per run, using NCCLS EP5-A guidelines was 6.8% at 19.34 pg/mL, 4.4% at 76.03 pg/mL, 4.3% at 275.3 pg/mL, 5.4% at 99.88 pg/mL, and 5.7% at 363.9 pg/mL. The LoQ for the assay at 20% CV was 4.8 pg/mL. Dilution and spiking studies showed an average recovery of 90-110%. A highly specific, sensitive, simplified and reproducible microplate Inhibin B assay has been developed to measure Inhibin B in serum and Li-Hep plasma. The performance of the assay is ideal for investigation into the physiologic role of Inhibin B in both men and women.

Dynamic measurements of serum inhibin B and estradiol: a predictive evaluation of ovarian response to gonadotrophin stimulation in the early stage of IVF treatment

OBJECTIVE

We dynamically measured serum inhibin B and estradiol in the early stage of hormonal stimulation to predict the ovarian response in in vitro fertilization (IVF) treatment.

METHODS

A total of 57 patients (<40 years of age) who underwent the first cycle of long protocol IVF or introcytoplasmic sperm injection (ICSI) treatment were included. Serum inhibin B, estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were measured four times: (1) on Day 3 of the menstrual cycle (basal); (2) on the day before the first administration of gonadotrophin (Gn) (Day 0); (3) on Day 1 of Gn therapy; and (4) on Day 5 of Gn therapy. Comparisons of these measurements with ovarian responses and pregnancy outcomes were made and analyzed statistically.

RESULTS

(1) On Day 1 and Day 5 of recombinant FSH (rFSH) stimulation, ovarian response, i.e., numbers of follicles, oocytes, fertilized oocytes, and embryos, had a positive correlation (r(s)=0.46~0.61, P=0.000) with raised inhibin B and estradiol concentrations, but a negative correlation (r(s)=-0.67~-0.38, P=0.000 or P<0.01) with total rFSH dose and total days of rFSH stimulation. (2) No significant variation (P>0.05) between the pregnant and non-pregnant groups on the basis of mean age or on all hormone concentrations at four times of the IVF cycle was observed. However, all the seven patients aged >35 years did not reach pregnancy.

CONCLUSIONS

(1) Serum inhibin B and estradiol concentrations obtained shortly after Gn therapy may offer an accurate and early prediction of ovarian response; (2) Low levels of serum inhibin B and estradiol obtained shortly after Gn stimulation indicate the need for a longer period of Gn treatment and a higher daily dosage; (3) No obvious pregnancy difference among patients of age <35 years was found; however, IVF pregnancy outcome is significantly lower in women of age >35 years.

Impact of GnRH ovarian stimulation protocols on intracytoplasmic sperm injection outcomes

BACKGROUND

Although a large number of studies have been conducted in relation to ovarian response and pregnancy after GnRH agonist and GnRH antagonist controlled ovarian hyperstimulation protocols, most of them used single or combinations of a few predictive factors, and none included the stimulation protocol in the multivariable analysis. The present study was thus primarily designed to investigate the predictive value of the stimulation protocol and to analyze the possible relationships between stimulation protocols and treatment outcomes after adjusting for a large set of variables that potentially affect reproductive outcomes. Factors related to pregnancy achievement and predictive of the number of oocytes retrieved and high quality of the embryos obtained were also analyzed.

METHODS

To analyze the impact of GnRH ovarian stimulation protocols on the independent predictors of ovarian response, high quality embryos and clinical pregnancy, two groups out of 278 ICSI treatment cycles were compared prospectively, 123 with a GnRH agonist and 155 with a GnRH antagonist, with multivariable analysis assessing outcomes after adjusting for a large set of variables.

RESULTS

Antagonists were significantly associated with lower length and total dose of GnRH, lower length of rFSH, and higher numbers of oocytes and high quality embryos, whereas the agonist presented a higher fertilization rate and probability of pregnancy. Significant predictors of retrieved oocytes and high quality embryos were the antagonist protocol, lower female age, lower serum levels of basal FSH and higher total number of antral follicles. Significant predictors of clinical pregnancy were the agonist protocol, reduced number of attempts, increased endometrial thickness and lower female age. The probability of pregnancy increased until 30 years-old, with a decline after that age and with a sharp decline after 40 years-old.

CONCLUSION

The models found suggest that not only the protocol but also factors as female age, basal FSH, antral follicles, number of attempts and endometrial thickness should be analyzed for counselling patients undergoing an ICSI treatment.

Serum anti-Müllerian hormone and inhibin B levels at ovulation triggering day can predict the number of immature oocytes retrieved in in vitro fertilization cycles

The aim of this study was to investigate whether serum levels of anti-Müllerian hormone (AMH) and inhibin B at ovulation triggering day correlate with the number of immature oocytes obtained from stimulated in vitro fertilization (IVF) cycles. Fifty-nine consecutive cycles of ovarian hyperstimulation and IVF were selected from 45 women who had tubal (n=18) or unexplained infertility (n=27) and obtained at least one oocyte. Serum levels of AMH and inhibin B at ovulation triggering day were measured by enzyme-linked immunosorbent assay (ELISA). Univariate analysis and multiple regressions revealed that serum AMH or inhibin B levels were significantly correlated with immature oocyte count and the correlation coefficients were higher compared to the mature oocyte count. Serum AMH and inhibin B levels on triggering day seems to be more closely related with the immature oocyte count and thus could be good predictors to determine the immature oocyte count in IVF cycle.

Prognostic value of serum CA-125 measurements on stimulation day 1 and on the day of oocyte pickup in the prediction of IVF treatment outcome

PURPOSE

To assess whether serum levels of CA-125, a proposed marker of endometrial receptivity, are associated with pregnancy after IVF.

METHODS

42 IVF pregnancies were matched with nonpregnant controls. Twenty-eight additional unmatched pregnancies were included for the comparison of pregnancy outcomes. CA-125 concentrations were measured on stimulation day 1 (SD1) and at oocyte pickup (OPU). We analyzed association between CA-125 levels and establishment of pregnancy and its outcome; correlation between CA-125 concentrations and other parameters; differences in CA-125 levels between SD1 and OPU.

RESULTS

In pregnant, but not in nonpregnant patients, CA-125 levels decreased significantly from SD1 to OPU. There was no significant difference in CA-125 levels at either time point between pregnant and nonpregnant subjects. No significant correlation was found between CA-125 levels and any other clinical or laboratory parameters.

CONCLUSIONS

CA-125 measurements at the beginning of stimulation or at oocyte retrieval are not useful in predicting IVF outcome.