rFSH in medically assisted procreation: Evidence for ovarian follicular hyperplasia and interest of mass spectrometry to measure 17-hydroxyprogesterone and Δ4-androstenedione in serum

Loss of Anti-Müllerian Hormone Signaling in Mice Affects Trabecular Bone Mass in a Sex- and Age-Dependent Manner

Ovariectomy-induced osteoporosis in mice results from an abrupt loss of ovarian sex steroids. Anti-Müllerian hormone knockout (AMHKO) mice show a gradual but accelerated ovarian aging, and therefore may better resemble osteoporosis following natural menopause. To study the impact of AMH signaling deficiency on bone, we compared trabecular and cortical bone parameters in 2-, 4-, 10-, and 16-month-old male and female wild-type (WT), AMHKO, and AMH type II receptor knockout (MRKI) mice using micro computed tomography (microCT). Goldner's staining was performed to confirm the observed bone phenotype. Both male and female AMHKO and MRKI mice showed age-dependent loss of trabecular bone (P < 0.001). However, reproductive-aged female AMHKO and MRKI mice had higher BV/TV compared with WT (P < 0.001), coinciding with increased growing follicle numbers (P < 0.05) and increased estrus inhibin B levels (AMHKO: P < 0.001; MRKI: P < 0.05) but normal inhibin A, estrogen, and progesterone levels. In aged female AMHKO and MRKI mice BV/TV did not differ from WT mice due to greater trabecular bone loss between 10 and 16 months compared with WT mice. At these ages, AMHKO and MRKI mice had reduced growing follicle numbers (P < 0.05) and reduced inhibin B levels (P < 0.001). At age 10 months, female MRKI mice had increased cortical bone parameters compared with WT mice (P < 0.01). Bone parameters of male AMHKO and MRKI mice did not differ from male WT mice. In conclusion, AMH signaling deficiency results in a sex- and age-dependent effect on predominantly trabecular bone. Our results further suggest that reproductive hormones beyond estrogen may contribute to bone homeostasis.

Basal serum level of Δ4-androstenedione reflects the ovaries' ability to respond to stimulation in IVF cycles: setting up a new reliable index of both ovarian reserve and response

PURPOSE

Adequate androgen levels are necessary for regular follicular growth, progression beyond the pre-antral stage, and prevention of follicular atresia. The main purpose of this study was to investigate whether baseline androgen levels had a predictive value on stimulation outcomes in IVF cycles. The secondary purpose was to compare the possible predictive value of androgens with that of already known markers.

METHODS

The study included 91 infertile patients aged 30-45 years awaiting the first IVF cycle. All women underwent the same stimulation protocol and the same starting dose of recombinant FSH. As stimulation outcomes, the number of follicles recruited, estradiol and progesterone levels on the day of trigger, the total dose of gonadotropins administered, and the number of oocytes collected were recorded. Multiple linear regression and multivariate logistic regression were used to evaluate the significant predictive value of the variables for response to controlled ovarian stimulation (COS). By studying the reliability of different markers, an attempt was made to develop a single index with the highest predictive value.

RESULTS

Pearson's correlation revealed a statistically significant inverse correlation between oocytes collected and age (r =  - 0.333, p < 0.001) and a positive correlation with AMH (anti-müllerian hormone) (r = 0.360, p < 0.001), antral follicle count (AFC) (r = 0.639, p < 0.001), and androstenedione (Δ4-A) (r = 0.359, p < 0.001). No significant correlation was reported with FSH (r =  - 0.133, p = 0.207) and total testosterone (r = 0.180, p = 0.088). In COS good responders, the G-index (= AMH ng/mL*AFC/Δ4-A ng/dL) revealed a significantly higher level (p < 0.001) than AMH, AFC, and Δ4-A alone.

CONCLUSION

Baseline serum Δ4-A, presumably crucial for ensuring a regular follicular growth, is a reliable marker of ovarian response to stimulation. Since the ovarian capacity to respond to gonadotropins does not depend exclusively on the presence of follicles, we suggest a new index, the G-index, able to contemplate both the ovarian reserve and the Δ4-A level.