Follicular hormonal profile achieved in natural cycles does not affect spindle oocyte features in low responder patients

Abstract

OBJECTIVE: Low response to ovarian stimulation frequently reflects an age related decline in reproductive performance being a group of patients difficult to treat. We aimed to analyze whether the use of natural or stimulated cycles can modify the hormonal milieu of follicles as well as the spindle features of the associated oocytes in low responder patients. DESIGN: Prospective and descriptive study. MATERIALS AND METHODS: Were included 68 cycles of 57 low responder patients. In 26 cycles exogenous hyperstimulation strategy was used (group 1) (14 cycles using GnRH antagonist, 8 treated with GnRH agonist and 4 clomifen citrate) and 42 were natural cycles (group 2). Average of age was 35.7 and 37.2 respectively. Follicular fluids were analyzed for FSH, LH, estradiol (E2), progesterone (P4), testosterone and androstendione concentration by enzymoimmuneanalysis (MEIA). Were analyzed 53 meiotic spindles under the polarized light OosightTM optics. Chi-square, t-Student comparison tests and logistic regression analysis were used for statistical analysis, p values <0.05 were considered statistically different. RESULTS: The LH/FSH ratio found in follicular fluids were significantly higher in group 2 compared to group1 (2.4 vs 0.5), such differences didn't affect intrafollicular concentration of neither E2 (375436 vs 369103 pg/ml), P4 (8833 vs10202 ng/ml), androstendione (54,3 vs 47,8 ng/ml) nor testosterone (5.5 vs 7.8 ng/ml) respectively. Furthermore meiotic spindle was abnormal in 53.1% (17/32) of the oocytes from natural cycles and 57.1% (12/21) of stimulated ones. However, a positive significant correlation was found between intrafollicular LH/FSH ratio and the birefringence of the meiotic spindles of the associated oocytes r= 0,28 p=0.05. CONCLUSIONS: Follicular fluid gonadotrophins profile was higher in low responder patients undergoing natural cycles. The positive correlation between LH/FSH ratio and spindle retardance may indicate that using natural cycles in low responder patients may improve embryo quality.