Ovulation prediction in spontaneous and induced cycles: the role of ovarian reserve markers

Objective(s): To evaluate the role of day 3 serum; FSH, inhibin-B and estradiol, (biochemical markers), ultrasound measured antral follicle count AFC and ovarian volume OV (biophysical markers) in ovulation prediction in induced cycles in infertile patients with different induction protocols. Also, the secondary aim was to analyze the correlations between these markers and prediction of ovulation success in induced cycles with different induction protocols.
Design: Prospective comparative controlled study
Settings: Infertility Clinic, University Hospital , El Minia & IVF center, Egypt .
Patients: Eighty infertile patients (study group) classified into four subgroups, twenty patients each according to the method of ovulation induction and twenty matched fertile subjects (control group).
Interventions: Day 3 serum; inhibin-B, FSH and estradiol were measured together with transvaginal ultrasound measurements of the antral follicle count and ovarian volume in the study and the control groups. The study group was subdivided into four subgroups according the method of ovulation induction; whether clomiphene citrate (group I), or urinary follicle stimulating hormone (group II), or low dose recombinant follicle stimulating hormone (group III) or long protocol (group IV).
Main outcome measures: The predictive values of different screening markers in relation to ovulation. Other outcome measures were the analysis of the correlations between various biochemical and biophysical markers and prediction of ovulation success in induced cycles with different induction protocols.
Results: The predictive values of FSH (<10 IU/L), inhibin-B (> 45 pg/ml), estradiol (<75 pg/ml), AFC (> 6), and OV (>3 cm³) in relation to ovulation prediction were statistically comparable (P>0.05). Multivariate analysis of the variables that predict ovulation in induced cycles demonstrated that of the biochemical variables FSH was the most significant contributor to ovulation (R2 = 0.93, P ≤ 0.01), while of the biophysical variables AFC is the most significant one (R 2= 0.46, P ≤ 0.01).
Conclusions: Day 3 serum; FSH, inhibin-B and estradiol, ultrasound measured AFC and ovarian volume are comparable screening markers of the ovarian reserve in the general infertility patients. Of the biochemical factors the main predictor for ovulation in induced cycles is FSH while AFC is the main biophysical one.

Keywords
Ovulation prediction, FSH, Inhibin-B, estradiol, transvaginal ultrasound, antral follicle count AFC, ovarian volume OV, Infertility