Basal concentrations of oestradiol may predict the outcome of in-vitro maturation in regularly menstruating women.

Retrospectively it was examined whether the number of retrieved oocytes, the maturation rate and cleavage rate can be predicted in regularly menstruating women by the use of the following predictive variables on cycle day 3-4: the concentration of FSH, oestradiol, inhibin B and inhibin A in serum and and the number of ovarian follicles seen by vaginal ultrasound. The study included 132 consecutive aspirations in 100 women attending the clinic for in-vitro maturation due to male factor and/or tubal factor. Fifteen pregnancies were obtained after transfer in 83 cycles, giving a pregnancy rate of 15/132 (11%) per aspiration and 15/83 (18%) per transfer. The concentration of FSH and the number of follicles on day 3 predicted the number of oocytes retrieved, whereas these parameters did not predict the subsequent development of oocytes. No correlation was found between the inhibin B, inhibin A, oestradiol and the number of oocytes respectively. The group with a low concentration of oestradiol on cycle day 3 (threshold <200 pmol/l) (group 1, n = 106 cycles) had a significantly higher pregnancy rate compared to the group with a higher concentration (group 2, n = 26 cycles) (14 versus 0% per aspiration, P = 0.03). The group with a low concentration of oestradiol was subdivided according to the concentration of inhibin A. Group 1a: low inhibin A (threshold <10 pg/ml, n = 84 cycles) and group 1b: high inhibin A concentration (> or =10 pg/ml, n = 19). The pregnancy rate in group 1a (14/84, 17%) differed significantly from group 1b (0/19, 0%) (P = 0.03). It is concluded that a low basal concentration of oestradiol (<200 pmol/l) was shown to be a useful prognostic factor of pregnancy in IVM. The concentration of inhibin A (<10 pg/ml) was of added value.