Endogenous luteinizing hormone concentration and IVF outcome during ovarian stimulation in fixed versus flexible GnRH...

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.

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.

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.

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.

Fixed and flexible GnRH antagonist protocols did not produce an oscillation of endogenous LH values correlated to the outcome of ovarian stimulation.