Fig. 2.

Relationship between IVF and pregnancy outcomes with increasing serum estradiol levels represented in quartiles. The rate of oocyte fertilization (a), stage specific embryo development (b), positive pregnancy test (c), embryo implantation (d), proportion of patients with clinical pregnancy after a positive pregnancy test (e), singleton live birth (f) and spontaneous miscarriage (g) increased with increasing serum estradiol level until 3rd quartile, with subsequent non-significant downward trend. Groups with different letters are significantly different. *p < 0.05 compared to other groups