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