RESUMEN
Ovarian monitoring requires the determination of serum estradiol and progesterone levels. We investigated whole follicular steroidogenesis under rFSH in medically assisted procreation (MAP: 26 IVF, 24 ICSI) compared to 11 controls (IUI). Estrone, estradiol, Δ4-androstenedione, testosterone, progesterone and 17-hydroxyprogesterone were measured by immunoassay and mass spectrometry except for estrogens. At the start of a spontaneous or induced cycle, steroids levels fluctuated within normal ranges: estradiol (314-585 pmol/L), estrone (165-379 pmol/L) testosterone (1.3-1.6 nmol/L), Δ4-androstenedione (4.5-5.6 nmol/L), 17-hydroxyprogesterone (2.1-2.2 nmol/L) and progesterone (1.8-1.9 nmol/L). 17-hydroxyprogesterone, Δ 4-androstenedione and estradiol predominated. Then estradiol and oestrone levels rise, but less markedly for oestrone in IUI. In MAP, rFSH injections induce a sharp increase in estrogens associated with a rise in 17-hydroxyprogesterone and Δ4-androstenedione levels, disrupting oestrogen/androgen ratios. rFSH stimulation induces an ovarian hyperplasia and Δ4pathway which could become abnormal. Determining 17-hydroxyprogesterone and Δ4-androstenedione levels with LC-MS/MS may therefore be useful in managing recurrent MAP failures.
