Does elevated luteinizing hormone level before trigger mean premature luteinizing hormone surge in advanced-aged women undergoing mild ovarian stimulation?

To explore whether elevated luteinizing hormone (LH) level before trigger means premature LH surge in advanced aged women undergoing mild ovarian stimulation.To retrospectively analyze 235 in vitro fertilization/intracytoplasmic sperm injection cycles in women >35 years old with the poor ovarian response (POR) from January 2012 to March 2016. Cycles are named Group 1, Group 2, and Group 3, being treated with gonadotropin-releasing hormone antagonist protocol (76 cycles), mild stimulation protocol using clomiphene citrate (73 cycles), and tamoxifen (86 cycles), respectively.The dynamic change of LH level during stimulation; the proportion of an elevated LH level defined as >10 IU/L on trigger day; the proportion of premature ovulation in each group.Serum LH level increased early in Group 2 and Group 3 and remained significantly higher than that in Group 1 during stimulation. In a sequence of three groups, the proportion of elevated LH levels before the trigger was 11.84, 43.8, and 37.21% (p＜.001) respectively. And the proportion of premature ovulation in patients with elevated LH levels was 11.11, 18.75, and 25% (p = .11) respectively.Elevated LH level before trigger does not mean premature LH surge in women more than 35 years old with POR undergoing mild ovarian stimulation with clomiphene or tamoxifen.