FOLLICULOCENTESIS - A NOVEL RESEARCH TECHNIQUE TO INVESTIGATE THE INTRAFOLLICULAR ENDOCRINE MICROENVIRONMENT

During development of the dominant follicle, the avascular granulosa c ells and oocyte are exposed to the follicular fluid endocrine microenv ironment. An alteration in the endocrine characteristics of follicular fluid affects follicular steroidogenesis, oocyte maturation, ovulatio n and subsequent corpus luteum function, In-vitro studies on pooled fo llicular fluid from ovarian specimens lacked temporal precision betwee n menstrual and follicular endocrine events. We have established a new technique, termed folliculocentesis (FC), to sample follicular fluid from the dominant ovarian follicle without compromising its growth or function during the mid- to late follicular phase. A total of 38 subje cts with regular ovulatory cycles each underwent two identical cycles of hormone and follicle growth monitoring: one cycle served as the con trol, and FC was performed during the second cycle, During all cycles, plasma luteinizing hormone (LH), oestradiol and ultrasound monitoring of follicle growth were commenced on day 7 and continued until after ovulation, During FC cycles, 200 mu l of follicular fluid were aspirat ed from the dominant follicle using transvaginal ultrasound guidance w hen the follicle diameter reached greater than or equal to 10 mm. Six subjects were excluded from the study because of incomplete or invalid endocrine data, In all, 32 subjects completed both the FC and control cycles, The follicle growth pattern, maximum follicle diameter, plasm a oestradiol, oestradiol peak, plasma LH, LH surge and follicular phas e length were similar during FC and control cycles, A total of 50 vali d follicular fluid samples were obtained when the dominant follicle wa s sampled once, twice or three times during the same cycle and from th e same follicle in 15, 16 and one subjects respectively, The follicula r fluid samples contained steroid concentrations consistent with those of the mid- to late follicular phase, We conclude that the FC procedu re is safe, easy to perform and does not affect follicle growth or hor mone dynamics. Analysis of the follicular fluid samples is expected to provide us with valuable in-vivo information about ovarian endocrinol ogy.