endogenous luteinizing hormone concentration and ivf outcome during ovarian stimulation in fixed versus flexible gnrh antagonist protocols: an rct

Background: luteinizing hormone (lh) is essential for normal follicular development and oocyte maturation. in particular, fluctuations of lh during the follicular phase have a significant impact on morphological and functional changes of the oocyte and determine its meiotic status and ability to be fertilized. objective: this prospective randomized controlled trial examined effects of endogenous follicular phase lh levels on oocyte maturity and ivf outcomes in fixed vs. flexible in vitro fertilization. materials and methods: normo-ovulatory women age <39 yr (n=213) were randomized to fixed or flexible gonadotrophin-releasing hormone (gnrh) antagonist protocols. follicular phase lh, estradiol, and progesterone profiles were measured. oocytes retrieved, implantation rate, and pregnancy rate were compared between the two groups. results: lh profiles were similar in both protocols. a lower trend of lh values at the end of ovarian stimulation correlated significantly with a higher pregnancy rate, regardless of protocol (p=0.02). estradiol levels were statistically different with respect to time points within treatment groups (p<0.0001), but not between groups (p=0.43), or pregnancy outcomes (p=0.2595). progesterone profiles were similar between groups. no differences were found in retrieved oocytes numbers, fertilization rate or embryos obtained. significantly, younger age and a higher number of antral follicles were correlated with positive results. conclusion: fixed and flexible gnrh antagonist protocols did not produce an oscillation of endogenous lh values correlated to the outcome of ovarian stimulation.