Associação entre a duração do edema endometrial e os parâmetros reprodutivos no estro, diestro e a relação com a fertilidade em éguas

Abstract

Several associations among reproductive parameters during estrus and diestrus - such as the duration and intensity of endometrial edema, pre-ovulatory follicle diameter, corpus luteum (CL) size and progesterone concentration - have been previously described. However, no studies have examined the relationship between the duration of endometrial edema - which has been positively associated with uterine receptivity and fertility in mares - and other key parameters observed during estrus and diestrus. Therefore, the objective of this study was to evaluate the relationship between the Days of Endometrial Edema (DEdema) and the parameters: Maximum Edema (MEdema), Largest Pre-ovulatory Follicle (LPF), CL size and uterine tone on day 5 (CLD5 and TD5), progesterone concentration (P4), and fertility. A total of 88 cycles from 36 mares were evaluated and divided into Short Estrus (SE), Long Estrus (LE), Inseminated (AI), and Non-Inseminated (N-AI) groups. From the detection of a dominant follicle and uterine edema ≥1.5, mares were monitored daily until ovulation (D0). During this period, data on dominant follicle diameter and endometrial edema were recorded. On D5, CL size and uterine tone were assessed and blood was collected for P4 measurement. Of all cycles, 30.7% (27/88) were SE and 69.3% (61/88) LE. Significant correlations were observed between DEdema and the variables: LPF (p = 0.001; r = 0.32), MEdema (p = 0.002; r = 0.31), and TD5 (p = 0.01; r = 0.28). Furthermore, DEdema was associated with higher pregnancy rates. In conclusion, the duration of endometrial edema influences key estrous cycle parameters, as well as fertility.