Adding serum estradiol measurements to ultrasound monitoring does not change the yield of mature oocytes in IVF/ICSI.

In a non-randomized, comparative prospective study (416 patients) we compared the outcome of IVF/ICSI in two parallel control groups: one in which patients were followed up using combined monitoring (ultrasound plus serum estradiol monitoring, the UHM group) and one in which only ultrasound monitoring was used (the UM group). This study has taken the number of mature oocytes at the moment of egg retrieval as its primary end variable. After adjustment for age, gravidity, antagonist protocol, AMH and infertility diagnosis, the average difference in number of mature oocytes between the UHM group and the UM group was -0.4 (95% CI: -1.7 to 1.0), which met our definition of clinical equivalence (95% CI for the adjusted mean difference between -2 and 2). Larger studies are still needed to evaluate the differences in the live birth rates per cycle and to further confirm that blood sampling definitively has no added value in monitoring ovarian stimulation for IVF/ICSI.