Preovulatory follicular fluid: relationships to ovarian stimulation protocol, fertilization, and sperm penetration in vitro

The levels of steroid hormones and cytokines in individual follicles are not associated with the fertilization outcome after intracytoplasmic sperm injection

OBJECTIVE

To investigate the association between the levels of two steroid hormones and eight cytokines in fluids from individual follicles and the fertilization outcome of the oocytes derived from the same follicles.

DESIGN

Prospective study.

SETTING

University hospital.

PATIENT(S)

Forty-three women participating in intracytoplasmic sperm injection (ICSI)/ET cycles.

INTERVENTION(S)

The ovarian stimulation followed the multidose GnRH antagonist protocol. ICSI was performed in mature oocytes. The concentrations of estradiol, progesterone, tumor necrosis factor-alpha, interleukin (IL) -1beta, IL-6, vascular endothelial growth factor, leptin, basic fibroblast growth factor, epidermal growth factor, and insulin-like growth factor-I were measured by immunoassay methods in the follicles from which the mature oocytes were derived.

MAIN OUTCOME MEASURE(S)

The concentrations of the above hormones and cytokines in individual follicles and the fertilization outcome of the oocytes derived from the same follicles.

RESULT(S)

The intrafollicular concentrations of the above factors were not significantly associated with the fertilization outcome. These factors were not correlated with embryo quality, with the exception of leptin, which was weakly associated with embryo score (R = 0.276).

CONCLUSION(S)

The intrafollicular concentrations of the above factors cannot predict the fertilization outcome after ICSI.

Concentrations of gonadotrophins and steroids in pre-ovulatory follicular fluid and serum in relation to stimulation protocol and outcome of assisted reproduction treatment

In this prospective, randomized study, concentrations of gonadotrophins and steroids in pre-ovulatory follicular fluid (FF) and serum were related to type of stimulation protocol as well as to the outcome of assisted reproduction in 280 women subjected to the long protocol gonadotrophin-releasing hormone (GnRH) agonist pituitary down-regulation and ovarian stimulation with either human menopausal gonadotrophin (HMG) or recombinant FSH. In the women treated with HMG, concentrations of LH, FSH, oestradiol and androstenedione in FF were significantly higher, and those of human chorionic gonadotrophin (HCG) and progesterone significantly lower, than in the women treated with recombinant FSH (rFSH). More women became pregnant and delivered in the HMG than in the rFSH group. These differences, however, were not statistically significant. Concentrations of FSH in serum and of FSH and LH in FF were significantly higher in conception than in non-conception cycles, whereas all other hormone concentrations in FF and serum were similar. The present study demonstrates that the pre-ovulatory follicular fluid hormone profile is significantly influenced by the gonadotrophin preparation used for ovarian stimulation, and suggests that ovarian stimulation with HMG results in an intra-follicular hormone profile more similar to that characterizing conception cycles than stimulation with rFSH. However, as the present data represent means of FF hormone profiles, they do not allow the conclusion of a direct correlation between the intra-follicular concentration of a certain hormone and the ability of the corresponding embryo to implant and establish an ongoing pregnancy.

Human ovarian steroid secretion in vivo: effects of GnRH agonist versus antagonist (cetrorelix)

BACKGROUND

In order to investigate whether gonadotrophin-releasing hormone (GnRH) antagonists exert a significant effect on steroid secretion in vivo compared with GnRH agonists, concentrations of sex steroid hormones (oestradiol, progesterone and testosterone) were studied in follicular fluid from women undergoing ovarian stimulation and treated with either GnRH agonist or antagonist. In addition, the correlation between follicular fluid steroid hormone concentrations and variables of follicular and oocyte development was evaluated.

METHODS

Microparticle enzyme immunoassay and radioimmunoassays were used.

RESULTS

The mean (SEM) follicular fluid oestradiol concentration was significantly lower in patients treated with GnRH antagonist than in those treated with GnRH agonist (542.0 +/- 76.9 versus 873.0 +/- 105.1 pg/ml, P = 0.02), which correlates with the mean serum oestradiol concentrations found in these two groups. No significant differences were found between groups in follicular fluid progesterone concentrations. Women undergoing GnRH antagonist treatment showed similar concentrations of follicular fluid testosterone compared with GnRH agonist-treated women (14.8 +/- 1.1 versus 13.3 +/- 2.7 ng/ml). The oestradiol:testosterone ratio was markedly reduced in women treated with GnRH antagonist (49.1 +/- 2.3 versus 60.1 +/- 4.4, P = 0.04). In contrast, no differences were found either in the progesterone:testosterone ratio, or in the oestradiol:progesterone ratio.

CONCLUSIONS

GnRH antagonist therapy in women undergoing ovarian stimulation had a significant effect on ovarian follicular steroidogenesis.

Is there evidence for preferential delivery of ovarian estradiol to the endometrium?

OBJECTIVE

To determine the direction of delivery of E(2) in the female pelvis by assessing the ratio of endometrial to serum E(2) in women whose ovaries were stimulated to produce E(2) with women who received exogenous E(2).

DESIGN

Prospective comparative study.

SETTING

University-based ART program.

PATIENT(S)

Oocyte donors and recipients of donor oocytes.

INTERVENTION(S)

Micronized E(2) administered by the oral or vaginal route and oocyte donation.

MAIN OUTCOME MEASURE(S)

Serum and endometrial levels of E(2).

RESULT(S)

Serum E(2) levels were significantly higher in women who underwent controlled ovarian hyperstimulation (COH) and women receiving exogenous E(2) by the vaginal route than in those who received oral E(2). Levels of E(2) in endometrial tissue were similar in women who underwent COH and those receiving oral E(2). Endometrial E(2) levels in women who underwent vaginal administration were significantly higher than those in the oral E(2) or COH groups. The ratio of endometrial to serum E(2) was highest in women who underwent vaginal E(2) and lowest in those undergoing COH.

CONCLUSION(S)

Vaginal administration of micronized E(2) results in preferential absorption of E(2) into the endometrium, consistent with a "uterine first pass" effect. Since endogenous E(2) produced the smallest ratio of E(2) between the endometrium and serum, E(2) produced by the ovaries is not preferentially delivered to the uterus.

Recombinant human follicle stimulating hormone versus human menopausal gonadotrophin induction: effects in mature follicle endocrinology

To investigate follicular effects of recombinant human follicle stimulating hormone (rhFSH) induction on women with polycystic ovary syndrome (PCOS), steroid content was compared in mature follicles obtained using a long luteinizing hormone-releasing hormone agonist plus rhFSH or human menopausal gonadotrophin (HMG) in PCOS women and controls participating in an in-vitro fertilization programme. Follicular fluids (144 samples) were collected at oocyte retrieval by individual selective aspiration. Oocyte maturity and fecundability were assessed. Plasma and intrafollicular 17beta-oestradiol, progesterone, testosterone concentrations were assayed individually. No significant difference was seen in oocyte maturity and fecundability between PCOS and controls following rhFSH, or between PCOS rhFSH and HMG group. 17beta-oestradiol, testosterone and progesterone concentrations were lower in PCOS follicular fluid following rhFSH than HMG but the difference was not significant. Progesterone concentration, 17beta-oestradiol/progesterone, 17beta-oestradiol/testosterone were significantly different between the two induction groups, for PCOS fertilized oocyte follicles (P = 0.01, P < 0.05 and P < 0.05 respectively). Steroidogenic enzymatic activity seems to be regulated in healthy follicular cells in PCOS as well as in normal patients upon ovarian induction. Following rhFSH, higher PCOS follicular progesterone concentrations leading to a theoretically increased fecundability could suggest that recombinant FSH is a better inducer which needs to be confirmed.

Comparison between steroid hormones and cortisol in serum and follicular fluid in stimulated and unstimulated cycles of in vitro fertilization patients

The present study was undertaken to evaluate the effects of the concentrations of serum and follicular fluid steroids and cortisol levels on the establishment of pregnancies in in vitro fertilization (IVF). Our study group consisted of 42 women (group A) who received gonadotropins for induction of ovulation for IVF. The control group included 23 women (group B) who underwent in vitro fertilization without stimulation. Serum estradiol and progesterone levels were significantly higher in group A than in group B. Serum and follicular fluid cortisol levels were similar in both groups A and B. There was no significant difference in the fertilization rates of the stimulated or unstimulated cycles. However, there were no pregnancies in group B whereas there was a 28.5% pregnancy rate in group A. There were no correlations between the estradiol, progesterone and cortisol levels when compared to the oocyte maturity and the fertilization rates in both groups of patients.

Estrogen biosynthesis--regulation, action, remote effects, and value of monitoring in ovarian stimulation cycles

OBJECTIVE

To review current knowledge regarding estrogen biosynthesis, its regulation and action, specifically concerning local as opposed to remote effects of this hormone, and to examine the effectiveness and prognostic value of monitoring hormone concentrations and endometrial response in cycles of controlled ovarian hyperstimulation.

DATA IDENTIFICATION AND SELECTION

Studied that relate specifically to estrogen biosynthesis, enzymatic pathways, estrogen receptor physiology, and the clinical aspects of estrogen monitoring were identified through literature and Medline searches.

RESULTS

Folliculogenesis is the basic unit of ovarian activity, which has a dual purpose: oocyte maturation and steroid production. Steroidogenic granulosa and theca cells cooperate under gonadotropin control to produced estrogens by stimulating synthesis of steroidogenic enzyme messenger RNAs. Steroid synthesis is amplified further by local growth factors and follicular cell multiplication. Estrogen synthesis is directed by FSH, and only small amounts of LH are needed to amplify the follicular estrogenic potential. However, the growth of preovulatory follicles can proceed without LH, under FSH regulation only, even in the presence of low peripheral estrogen levels. Oocyte maturation and fertilization may proceed independently of ambient estrogen levels, leading to the assumption that estrogen exerts a minimal autocrine-paracrine function. The notable effect of follicular estrogen production is to promote adequate receptive endometrium for embryo implantation. Clinical treatment cycles may be monitored more effectively by evaluating end-organ response to estrogen rather than by evaluating absolute serum E2 concentrations or sonographic follicular measurements.

CONCLUSION

Follicular estrogen production is regulated by a complex set of signals that synergize to produce optimal steroidogenesis. Most importantly, the effect of estrogen is truly an endocrine effect, as it prepares the endometrium for implantation. Therefore, the goal of effective treatment and monitoring strategies should focus on direct assessment of the biologic activity of estrogen as it optimizes endometrial receptivity in anticipation of subsequent implantation.

Elevated serum progesterone levels on the day of human chorionic gonadotropin administration do not predict outcome in assisted reproduction cycles

OBJECTIVE

To determine if the level of serum P drawn on the day of hCG administration predicts assisted reproductive technology (ART) outcome in patients undergoing stimulation with hMG under GnRH agonist (GnRH-a) suppression.

DESIGN

Retrospective P assay of stored serum.

PATIENTS

One hundred seventy-one patients (189 cycles) who had undergone GnRH-a suppression (leuprolide acetate or nafarelin) and stimulation with hMG for an ART procedure.

MAIN OUTCOME MEASURES

Progesterone RIA of serum obtained on the day of hCG administration. Measurement of sequential serum LH values by RIA in those patients with the highest P levels.

RESULTS

Pregnancy rates per oocyte retrieval were not correlated with the P level before hCG administration. There were 18 of 54 (33.3%) clinical pregnancies in those cycles with P < 0.9 ng/mL (conversion factor to SI unit, 3.180) and 42 of 135 (31.1%) clinical pregnancies in cycles with a P > or = 0.9 ng/mL. Significantly higher serum E2 levels and numbers of of follicles and oocytes obtained were observed in the high P cycles. There were no differences in the number of oocytes fertilized, the number of embryos transferred, or the implantation rate. However, a significantly higher percentage of mature oocytes were fertilized in the low P cycles (73%), as compared with the high P cycles (60%).

CONCLUSIONS

Serum P levels before hCG administration do not predict the outcome of ART cycles in patients suppressed with GnRH-a before hMG stimulation. Lower fertilization rates observed in the high P cycles did not have an effect on clinical outcome.

Tumour-associated antigens, CEA, CA 125 and SCC in serum and follicular fluid of stimulated and unstimulated cycles

Serum and follicular fluid levels of CEA, CA 125 and SCC of women participating in an IVF program, in 42 cycles stimulated with GnRH-a and gonadotropins and in 26 unstimulated cycles triggered with HCG, were evaluated and compared with (a) steroid and gonadotropin levels, (b) the results of IVF, and (c) serum values in a control group of women with spontaneous normal ovulatory cycles. In the control group, serum antigens did not vary significantly during the 3 phases of the cycle. In stimulated cycles the median values in serum were 0.7 ng/ml (range, 0.0-2.1) for CEA, 14.0 U/ml (3.3-32.4) for CA 125 and 2.05 ng/ml (1.1-17.8) for SCC, whereas the median values in follicular fluid were 0.6 (0.0-27.9), 21.5 (0-670) and 21.4 (1-360), respectively. In unstimulated cycles the median values and ranges in serum were 0.9 (0.4-3.9), 12.1 (4.8-63.4) and 1.85 (0.7-4.4), respectively, whereas in follicular fluid they were 2.9 (0.4-180.7), 32 (1.7-600) and 231 (10.8-904). Different follicles of the same patients in stimulated cycles showed a wide divergence for all three antigens. In unstimulated cycles all three antigens in follicular fluid were strongly-correlated and a significant inverse correlation was observed between LH and both CA 125 and SCC in serum. In either group of cycles, no significant relationship was found between any serum or follicular fluid antigen and estradiol or testosterone, pregnancy rate, or oocyte quality and fertilization.(ABSTRACT TRUNCATED AT 250 WORDS)

Preovulatory follicular fluid steroid levels in stimulated and unstimulated cycles triggered with human chorionic gonadotropin

The purpose of this study was to analyze follicular fluid (FF) samples for steroid levels from stimulated and unstimulated cycles triggered with human chorionic gonadotropin (hCG) and to assess the influence of controlled ovarian hyperstimulation and luteinizing hormone/hCG on these levels. Spontaneous ovulatory cycles were monitored with serial ultrasound examinations, and hCG 10,000 IU was given when the lead follicle was mature. Fourteen FF samples yielding fertilizable oocytes were compared with 13 FF samples from controlled ovarian hyperstimulation cycles. Progesterone (P) was higher in controlled ovarian hyperstimulation than in unstimulated cycles (9.0 +/- 1.2 micrograms/mL versus 4.4 +/- 0.6 microgram/mL; mean +/- SEM), whereas estradiol (E2) was lower (0.8 +/- 0.1 microgram/mL versus 1.3 +/- 0.2 microgram/mL), resulting in a higher P:E2 ratio (15.5 +/- 3.3 versus 4.4 +/- 0.7). Androstenedione (A), testosterone (T), and T:E2 ratios were all higher in unstimulated than controlled ovarian hyperstimulation cycles. We conclude that controlled ovarian hyperstimulation is associated with increased FF P, decreased FF E2, T, and A levels, and decreased T:E2 ratios, suggesting altered steroidogenesis and enhanced follicular aromatase activity.

Effects of leuprolide acetate on follicular fluid hormone composition at oocyte retrieval for in vitro fertilization

The follicular fluid (FF) in 91 follicles from 17 women treated with leuprolide acetate (LA) before stimulation with gonadotropins for in vitro fertilization were analyzed for estradiol (E2), progesterone (P), androstenedione, prolactin, and human chorionic gonadotropin (hCG) and compared with the concentrations in 128 follicles from 31 women treated with gonadotropins alone. The FF E2 concentration in LA-treated patients was significantly lower than in non-LA patients for all oocyte maturational stages. Follicles containing metaphase II oocytes had significantly lower concentrations of P and hCG in LA-treated patients. These differences persisted when analysis was limited to follicles whose oocytes fertilized normally. These data indicate that in the presence of LA, normal oocyte maturation can occur despite lower intrafollicular concentrations of E2 and P.

Relationships between follicular fluid steroid hormone concentrations, oocyte maturity, in vitro fertilization and embryonic development in the rhesus monkey

Oocytes and matched samples of follicular fluid (FF) were obtained from 70 follicles of five rhesus monkeys stimulated with either pregnant mare serum gonadotropin or human menopausal gonadotropin. Follicular aspiration was performed 30-32 h after human chorionic gonadotropin administration. The concentrations of estradiol (E2), progesterone (P), testosterone (T), and dihydrotestosterone (DHT) in FF were measured. Twenty-six percent of oocytes were classified as mature (M), 41% matured in vitro (Miv), 13% were dysmature, and 20% atretic. M oocytes were associated with significantly higher levels of P and a higher P:E2 ratio. There were no differences in hormone levels associated with fertilized and nonfertilized oocytes. Thirty-five embryos developed to the six- to eight-cell stage in vitro, of which 13 exhibited optimal cleavage rates. Significantly lower levels of E2 and higher P:E2 ratios were associated with the more rapidly cleaving embryos. Proportionally more embryos showing optimal cleavage rates developed from M compared to Miv oocytes, and only embryos derived from M oocytes developed to blastocysts in culture. Optimal cleavage rates to the six- to eight-cell stage in vitro, rather than fertilization rates, are a better indicator of (subsequent) developmental capacity, and, in this study, embryonic development was closely associated with the maturity of the oocyte at recovery.