Growth hormone, oestradiol, progesterone and testosterone concentrations in follicular fluid after ovarian stimulation with various regimes for assisted reproduction

Non-invasive oocyte quality assessment

Oocyte quality is perhaps the most important limiting factor in female fertility; however, the current methods of determining oocyte competence are only marginally capable of predicting a successful pregnancy. We aim to review the predictive value of non-invasive techniques for the assessment of human oocytes and their related cells and biofluids that pertain to their developmental competence. Investigation of the proteome, transcriptome, and hormonal makeup of follicular fluid, as well as cumulus-oocyte complexes are currently underway; however, prospective randomized non-selection-controlled trials of the future are needed before determining their prognostic value. The biological significance of polar body morphology and genetics are still unknown and the subject of debate. The predictive utility of zygotic viscoelasticity for embryo development has been demonstrated, but similar studies performed on oocytes have yet to be conducted. Metabolic profiling of culture media using human oocytes are also limited and may require integration of automated, high-throughput targeted metabolomic assessments in real time with microfluidic platforms. Light exposure to oocytes can be detrimental to subsequent development and utilization of time-lapse imaging and morphometrics of oocytes is wanting. Polarized light, Raman microspectroscopy, and coherent anti-Stokes Raman scattering are a few novel imaging tools that may play a more important role in future oocyte assessment. Ultimately, the integration of chemistry, genomics, microfluidics, microscopy, physics, and other biomedical engineering technologies into the basic studies of oocyte biology, and in testing and perfecting practical solutions of oocyte evaluation, are the future for non-invasive assessment of oocytes.

New Insight into Sperm Capacitation: A Novel Mechanism of 17β-Estradiol Signalling

17β-estradiol (estradiol) is a natural estrogen regulating reproduction including sperm and egg development, sperm maturation—called capacitation—and sperm–egg communication. High doses can increase germ cell apoptosis and decrease sperm count. Our aim was to answer the biological relevance of estradiol in sperm capacitation and its effect on motility and acrosome reaction to quantify its interaction with estrogen receptors and propose a model of estradiol action during capacitation using kinetic analysis. Estradiol increased protein tyrosine phosphorylation, elevated rate of spontaneous acrosome reaction, and altered motility parameters measured Hamilton-Thorne Computer Assisted Semen Analyzer (CASA) in capacitating sperm. To monitor time and concentration dependent binding dynamics of extracellular estradiol, high-performance liquid chromatography with tandem mass spectrometry was used to measure sperm response and data was subjected to kinetic analysis. The kinetic model of estradiol action during sperm maturation shows that estradiol adsorption onto a plasma membrane surface is controlled by Langmuir isotherm. After, when estradiol passes into the cytoplasm, it forms an unstable adduct with cytoplasmic receptors, which display a signalling autocatalytic pattern. This autocatalytic reaction suggests crosstalk between receptor and non-receptor pathways utilized by sperm prior to fertilization.

Oral contraceptive pill, progestogen or oestrogen pretreatment for ovarian stimulation protocols for women undergoing assisted reproductive techniques

BACKGROUND

Among subfertile women undergoing assisted reproductive technology (ART), hormone pills given before ovarian stimulation may improve outcomes.

OBJECTIVES

To determine whether pretreatment with the combined oral contraceptive pill (COCP) or with a progestogen or oestrogen alone in ovarian stimulation protocols affects outcomes in subfertile couples undergoing ART.

SEARCH METHODS

We searched the following databases from inception to January 2017: Cochrane Gynaecology and Fertility Group Specialised Register, The Cochrane Central Register Studies Online, MEDLINE, Embase, CINAHL and PsycINFO. We also searched the reference lists of relevant articles and registers of ongoing trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of hormonal pretreatment in women undergoing ART.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcomes were live birth or ongoing pregnancy and pregnancy loss.

MAIN RESULTS

We included 29 RCTs (4701 women) of pretreatment with COCPs, progestogens or oestrogens versus no pretreatment or alternative pretreatments, in gonadotrophin-releasing hormone (GnRH) agonist or antagonist cycles. Overall, evidence quality ranged from very low to moderate. The main limitations were risk of bias and imprecision. Most studies did not describe their methods in adequate detail. Combined oral contraceptive pill versus no pretreatmentWith antagonist cycles in both groups the rate of live birth or ongoing pregnancy was lower in the pretreatment group (OR 0.74, 95% CI 0.58 to 0.95; 6 RCTs; 1335 women; I² = 0%; moderate quality evidence). There was insufficient evidence to determine whether the groups differed in rates of pregnancy loss (OR 1.36, 95% CI 0.82 to 2.26; 5 RCTs; 868 women; I² = 0%; moderate quality evidence), multiple pregnancy (OR 2.21, 95% CI 0.53 to 9.26; 2 RCTs; 125 women; I² = 0%; low quality evidence), ovarian hyperstimulation syndrome (OHSS; OR 0.98, 95% CI 0.28 to 3.40; 2 RCTs; 642 women; I² = 0%, low quality evidence), or ovarian cyst formation (OR 0.47, 95% CI 0.08 to 2.75; 1 RCT; 64 women; very low quality evidence).In COCP plus antagonist cycles versus no pretreatment in agonist cycles, there was insufficient evidence to determine whether the groups differed in rates of live birth or ongoing pregnancy (OR 0.89, 95% CI 0.64 to 1.25; 4 RCTs; 724 women; I² = 0%; moderate quality evidence), multiple pregnancy (OR 1.36, 95% CI 0.85 to 2.19; 4 RCTs; 546 women; I² = 0%; moderate quality evidence), or OHSS (OR 0.63, 95% CI 0.20 to 1.96; 2 RCTs; 290 women, I² = 0%), but there were fewer pregnancy losses in the pretreatment group (OR 0.40, 95% CI 0.22 to 0.72; 5 RCTs; 780 women; I² = 0%; moderate quality evidence). There were no data suitable for analysis on ovarian cyst formation.One small study comparing COCP versus no pretreatment in agonist cycles showed no clear difference between the groups for any of the reported outcomes. Progestogen versus no pretreatmentAll studies used the same protocol (antagonist, agonist or gonadotrophins) in both groups. There was insufficient evidence to determine any differences in rates of live birth or ongoing pregnancy (agonist: OR 1.35, 95% CI 0.69 to 2.65; 2 RCTs; 222 women; I² = 24%; low quality evidence; antagonist: OR 0.67, 95% CI 0.18 to 2.54; 1 RCT; 47 women; low quality evidence; gonadotrophins: OR 0.63, 95% CI 0.09 to 4.23; 1 RCT; 42 women; very low quality evidence), pregnancy loss (agonist: OR 2.26, 95% CI 0.67 to 7.55; 2 RCTs; 222 women; I² = 0%; low quality evidence; antagonist: OR 0.36, 95% CI 0.06 to 2.09; 1 RCT; 47 women; low quality evidence; gonadotrophins: OR 1.00, 95% CI 0.06 to 17.12; 1 RCT; 42 women; very low quality evidence) or multiple pregnancy (agonist: no data available; antagonist: OR 1.05, 95% CI 0.06 to 17.76; 1 RCT; 47 women; low quality evidence; gonadotrophins: no data available). Three studies, all using agonist cycles, reported ovarian cyst formation: rates were lower in the pretreatment group (OR 0.16, 95% CI 0.08 to 0.32; 374 women; I² = 1%; moderate quality evidence). There were no data on OHSS. Oestrogen versus no pretreatmentIn antagonist or agonist cycles, there was insufficient evidence to determine whether the groups differed in rates of live birth or ongoing pregnancy (antagonist versus antagonist: OR 0.79, 95% CI 0.53 to 1.17; 2 RCTs; 502 women; I² = 0%; low quality evidence; antagonist versus agonist: OR 0.88, 95% CI 0.51 to 1.50; 2 RCTs; 242 women; I² = 0%; very low quality evidence), pregnancy loss (antagonist versus antagonist: OR 0.16, 95% CI 0.02 to 1.47; 1 RCT; 49 women; very low quality evidence; antagonist versus agonist: OR 1.59, 95% CI 0.62 to 4.06; 1 RCT; 220 women; very low quality evidence), multiple pregnancy (antagonist versus antagonist: no data available; antagonist versus agonist: OR 2.24, 95% CI 0.09 to 53.59; 1 RCT; 22 women; very low quality evidence) or OHSS (antagonist versus antagonist: no data available; antagonist versus agonist: OR 1.54, 95% CI 0.25 to 9.42; 1 RCT; 220 women). Ovarian cyst formation was not reported. Head-to-head comparisonsCOCP was compared with progestogen (1 RCT, 44 women), and with oestrogen (2 RCTs, 146 women), and progestogen was compared with oestrogen (1 RCT, 48 women), with an antagonist cycle in both groups. COCP in an agonist cycle was compared with oestrogen in an antagonist cycle (1 RCT, 25 women). Data were scant but there was no clear evidence that any of the groups differed in rates of live birth or ongoing pregnancy, pregnancy loss or other adverse events.

AUTHORS' CONCLUSIONS

Among women undergoing ovarian stimulation in antagonist protocols, COCP pretreatment was associated with a lower rate of live birth or ongoing pregnancy than no pretreatment. There was insufficient evidence to determine whether rates of live birth or ongoing pregnancy were influenced by pretreatment with progestogens or oestrogens, or by COCP pretreatment using other stimulation protocols. Findings on adverse events were inconclusive, except that progesterone pretreatment may reduce the risk of ovarian cysts in agonist cycles, and COCP in antagonist cycles may reduce the risk of pregnancy loss compared with no pretreatment in agonist cycles.

Follicular steroid hormones as markers of oocyte quality and oocyte development potential

CONTEXT:

Various components of follicular fluid are suggested as biochemical predictors of oocyte quality. Previous studies of follicular steroid hormone levels have shown disparate results when related with fertilization outcomes.

AIM:

The objective of the study was to relate the levels of steroid hormones of each individual follicle with oocyte maturation, fertilization results, embryo quality, and pregnancy rates.

SETTINGS AND DESIGN:

Prospective cohort study in a university hospital.

METHODS:

In 31 patients, who underwent intracytoplasmic sperm injection, it was performed an ultrasound guided aspiration of follicular fluid of the first two mature follicles from each ovary. Follicular levels of estradiol, progesterone, testosterone, and dehydroepiandrosterone sulfate were measured by chemiluminescent immunoassay.

STATISTICAL ANALYSIS:

Generalized estimating equation model.

RESULTS:

In follicular fluids with mature oocyte presence, in normal as well as in failed fertilization, there was a positive correlation between follicular testosterone and progesterone (r = 0.794, P = 0.0001 and r = 0.829, P = 0.0001). Progesterone levels were higher in cases of normal fertilization compared to failed fertilization (P = 0.003). B quality embryos came from oocytes immersed in follicular fluids with higher estradiol values and higher estradiol/progesterone and estradiol/testosterone ratios than those of C quality (P = 0.01; P = 0.0009; P = 0.001). Estradiol levels were higher in patients who achieved pregnancy (P = 0.02).

CONCLUSION:

The analysis of follicular hormone composition could be considered as an additional tool in oocyte selection.

Non-canonical progesterone signaling in granulosa cell function

It has been known for over 3 decades that progesterone (P4) suppresses follicle growth. It has been assumed that P4 acts directly on granulosa cells of developing follicles to slow their development, as P4 inhibits both mitosis and apoptosis of cultured granulosa cells. However, granulosa cells of developing follicles of mice, rats, monkeys, and humans do not express the A or B isoform of the classic nuclear receptor for P4 (PGR). By contrast, these granulosa cells express other P4 binding proteins, one of which is referred to as PGR membrane component 1 (PGRMC1). PGRMC1 specifically binds P4 with high affinity and mediates P4's anti-mitotic and anti-apoptotic action as evidenced by the lack of these P4-dependent effects in PGRMC1-depleted cells. In addition, mice in which PGRMC1 is conditionally depleted in granulosa cells show diminished follicle development. While the mechanism through which P4 activation of PGRMC1 affects granulosa cell function is not well defined, it appears that PGRMC1 controls granulosa cell function in part by regulating gene expression in T-cell-specific transcription factor/lymphoid enhancer factor-dependent manner. Clinically, altered PGRMC1 expression has been correlated with premature ovarian failure/insufficiency, polycystic ovarian syndrome, and infertility. These collective studies provide strong evidence that PGRMC1 functions as a receptor for P4 in granulosa cells and that altered expression results in compromised reproductive capacity. Ongoing studies seek to define the components of the signal transduction cascade through which P4 activation of PGRMC1 results in the regulation of granulosa cell function.

Follicular-fluid anti-Mullerian hormone (FF AMH) is a plausible biochemical indicator of functional viability of oocyte in conventional in vitro fertilization (IVF) cycles

CONTEXT

Oocyte quality may be a governing factor in influencing in vitro fertilization (IVF) outcomes. However, morphological evaluation of oocyte quality is difficult in conventional IVF cycles. Follicular-fluid (FF), the site for oocyte growth and development, has not yet been sufficiently explored to obtain a marker indicative of oocyte quality. Anti-Mullerian hormone (AMH) is produced by granulosa cells of preantral and early-antral follicles and is released in FF.

AIM

To investigate AMH as a biochemical indicator of functional viability/quality of oocyte produced in the FF micro-environmental milieu.

SETTINGS AND DESIGN

Prospective study involving 132 cycles of conventional IVF-embryo transfer (ET) in infertile women.

SUBJECTS AND METHODS

AMH concentration was estimated in pooled FF on day of oocyte pickup. Cycles were sorted into low and high groups according to median (50 (th) centile) values of measurement. Main outcome measure was oocyte viability, which included morphological assessment of oocyte quality, fertilization rate, clinical pregnancy, and implantation rates.

STATISTICAL ANALYSIS

Graph-pad Prism 5 statistical package.

RESULTS

Low FF AMH group shows significantly higher percentage of top-quality oocytes (65.08 ± 24.88 vs. 50.18 ± 25.01%, P =0.0126), fertilization (83.65 ± 18.38 vs. 75.78 ± 21.02%, P =0.0171), clinical pregnancy (57.57 vs. 16.67%, P >0.0001), and embryo implantation rates (29.79 vs. 7.69%, P >0.0001) compared to high FF AMH group. FF AMH shares an inverse correlation with FF E2 (Pearson r = -0.43, r(2) = 0.18) and clinical pregnancy (Pearson r = -0.46, r(2) = 0.21). Threshold value of FF AMH for pregnancy is >1.750 ng/mg protein.

CONCLUSION

FF AMH is a plausible biochemical indicator of functional viability of oocyte in conventional IVF cycles.

Effect of estrogens on boar sperm capacitation in vitro

BACKGROUND

Mammalian sperm must undergo a series of controlled molecular processes in the female reproductive tract called capacitation before they are capable of penetrating and fertilizing the egg. Capacitation, as a complex biological process, is influenced by many molecular factors, among which steroidal hormone estrogens play their role. Estrogens, present in a high concentration in the female reproductive tract are generally considered as primarily female hormones. However, there is increasing evidence of their important impact on male reproductive parameters. The purpose of this study is to investigate the effect of three natural estrogens such as estrone (E1), 17beta-estradiol (E2) and estriol (E3) as well as the synthetical one, 17 alpha-ethynylestradiol (EE2) on boar sperm capacitation in vitro.

METHODS

Boar sperm were capacitated in vitro in presence of estrogens. Capacitation progress in control and experimental samples was analyzed by flow cytometry with the anti-acrosin monoclonal antibody (ACR.2) at selected times of incubation. Sperm samples were analyzed at 120 min of capacitation by CTC (chlortetracycline) assay, immunocytochemistry and flow cytometry with anti-acrosin ACR.2 antibody. Furthermore, sperm samples and capacitating media were analyzed by immunocytochemistry, ELISA with the ACR.2 antibody, and the acrosin activity assay after induced acrosomal reaction (AR).

RESULTS

Estrogens stimulate sperm capacitation of boar sperm collected from different individuals. The stimulatory effect depends on capacitation time and is highly influenced by differences in the response to estrogens such as E2 by individual animals. Individual estrogens have relatively same effect on capacitation progress. In the boar samples with high estrogen responsiveness, estrogens stimulate the capacitation progress in a concentration-dependent manner. Furthermore, estrogens significantly increase the number of acrosome-reacted sperm after zona pellucida- induced acrosomal reaction.

CONCLUSIONS

We demonstrate here the stimulatory effect of four different estrogens on boar sperm capacitation in vitro. According to our results, there is significant difference in the response to tested estrogens at different capacitation time and among individual animals. In animals with a high response to estrogens, there is a concentration-dependent stimulation of capacitation and individual estrogens have relatively the same effect. Effects of individual estrogens, differences in the response to them by individual animals, their time and concentration-dependent outcomes further contribute to our knowledge about steroidal action in sperm.

Oral contraceptive pill, progestogen or estrogen pre-treatment for ovarian stimulation protocols for women undergoing assisted reproductive techniques

BACKGROUND

For many subfertile women, assisted reproductive techniques (ART) is the only hope for a pregnancy and live birth. The combined oral contraceptive pill (OCP) given prior to the hormone therapy in an IVF cycle may result in better pregnancy outcomes of ART.

OBJECTIVES

To assess whether pre-treatment with combined OCPs, progestogens or estrogens in ovarian stimulation protocols affects outcomes in subfertile couples undergoing ART.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, PsycINFO. Other electronic resources on the Internet, reference list of relevant articles were also searched as well as the ESHRE abstracts (2008). All these searches were conducted in November 2008.

SELECTION CRITERIA

Randomised controlled trials of pre-treatment with combined OCP, progestogen or estrogen in subfertile women undergoing IVF/ICSI.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data and assessed risk of bias. We calculated Peto odds ratios for dichotomous data and weighted mean difference for continuous variables. Authors of trials were contacted in case of missing data.

MAIN RESULTS

No evidence of effect was found with regard to the number of live births when using a pre-treatment. However, the combined OCP in GnRH antagonist cycles, compared to no pre-treatment, is associated with fewer clinical pregnancies (Peto OR 0.69, P = 0.03) and more days and a higher amount of gonadotrophin therapy (respectively: MD 1.44, P < 0.00001; and MD 691.69, P < 0.00001). Also compared to placebo or no pre-treatment, a progestogen pre-treatment in GnRH agonist cycles, is associated with more clinical pregnancies (Peto OR 1.95, P = 0.007) and fewer ovarian cysts (Peto OR 0.21, P < 0.00001). At last, in estrogen pre-treated GnRH antagonist cycles, compared to no pre-treatment, more oocytes are retrieved (MD 2.01, P < 0.00001), but a higher amount of gonadotrophin therapy is needed (MD 207.08, P < 0.00001). For the other outcomes no evidence of effect was found or there were not enough studies available in the subgroup for pooling.

AUTHORS' CONCLUSIONS

There was evidence of improved pregnancy outcomes with progestogen pre-treatment and poorer pregnancy outcomes with a combined OCP pre-treatment. However, we conclude that major changes in ART protocols should not be made at this time, since the number of overall studies in the subgroups is small and reporting of the major outcomes is inadequate.

Progesterone activates a progesterone receptor membrane component 1-dependent mechanism that promotes human granulosa/luteal cell survival but not progesterone secretion

CONTEXT

Progesterone (P4) promotes its own secretion and the survival of human granulosa/luteal (GL) cells.

OBJECTIVE

The objective of these studies was to determine whether progesterone receptor membrane component-1 (PGRMC1) mediates P4's actions.

DESIGN

In vitro studies were conducted on GL cells from women undergoing in vitro fertilization and GL5 cells, which are derived from GL cells.

SETTING AND PATIENTS

GL cells were obtained from women undergoing fertility treatment at a university-based clinic and used for in vitro studies.

MAIN OUTCOME MEASURES

PCR, Western blot, and immunocytochemistry were used to detect various progestin binding proteins. (3)H-P4 binding kinetics were assessed on partially purified PGRMC1. Apoptosis was determined after culture by either TUNEL or DAPI staining. P4 was measured by an ELISA assay. PGRMC1 was depleted using small interfering RNA.

RESULTS

GL and GL5 cells expressed several P4 binding proteins including the nuclear progesterone receptor (PGR), progestin/adipoQ receptors (PAQR 7, 8, and 5) and PGRMC1. Ligand binding studies revealed that both P4 and the progestin, R5020, bound PGRMC1 with an EC(50) of approximately 10 nm. Interestingly, P4 inhibited apoptosis at concentrations in the 10 nm range, whereas R5020 stimulated P4 secretion at concentrations of at lease 16 mum. Depleting PGRMC1 attenuated P4's antiapoptotic action but failed to influence R5020-induced P4 secretion.

CONCLUSIONS

These studies conclusively demonstrate that in human GL cells PGRMC1 functions as a receptor through which P4 activates a signal cascade that prevents apoptosis. In contrast, PGRMC1 does not mediate P4's ability to acutely promote its own secretion.

Follicular fluid content and oocyte quality: from single biochemical markers to metabolomics

The assessment of oocyte quality in human in vitro fertilization (IVF) is getting increasing attention from embryologists. Oocyte selection and the identification of the best oocytes, in fact, would help to limit embryo overproduction and to improve the results of oocyte cryostorage programs. Follicular fluid (FF) is easily available during oocyte pick-up and theorically represents an optimal source on non-invasive biochemical predictors of oocyte quality. Unfortunately, however, the studies aiming to find a good molecular predictor of oocyte quality in FF were not able to identify substances that could be used as reliable markers of oocyte competence to fertilization, embryo development and pregnancy. In the last years, a well definite trend toward passing from the research of single molecular markers to more complex techniques that study all metabolites of FF has been observed. The metabolomic approach is a powerful tool to study biochemical predictors of oocyte quality in FF, but its application in this area is still at the beginning. This review provides an overview of the current knowledge about the biochemical predictors of oocyte quality in FF, describing both the results coming from studies on single biochemical markers and those deriving from the most recent studies of metabolomics.

Efficacy of low-dose human chorionic gonadotropin alone to complete controlled ovarian stimulation

OBJECTIVE

To prove that low-dose hCG alone can be clinically used to replace FSH-containing gonadotropins to complete controlled ovarian hyperstimulation (COH).

DESIGN

Controlled, prospective, randomized study.

SETTING

Academic center.

PATIENT(S)

Infertile patients who are candidates for assisted reproduction.

INTERVENTION(S)

Patients received [1] recombinant FSH or hMG throughout COH (group A); [2] ovarian priming with recombinant FSH/hMG followed by low-dose hCG (200 IU/day) alone (group B).

MAIN OUTCOME MEASURE(S)

Medication consumption; daily serum and follicular fluid (FF) measurements of LH, FSH, hCG, E2, P, T, and androstenedione (A); number and size of follicles; intracytoplasmic sperm injection (ICSI) outcome.

RESULT(S)

In group B: [1] duration and dose of recombinant FSH/hMG administration were reduced; [2] preovulatory serum hCG, E2, and T were higher, whereas FSH was lower; [3] FF hCG, E2, T levels, and E2/T, E2/A, and E2/P ratios were higher, whereas A was lower; [4] small but not large preovulatory follicles were reduced; [5] fertilization rates were higher; and [6] serum and FF P levels, and ICSI outcome did not differ.

CONCLUSION(S)

Low-dose hCG alone in the late COH stages: [1] reduced recombinant FSH/hMG consumption whereas ICSI outcome was comparable to traditional COH regimens; [2] stimulated follicle growth and maturation independent of FSH administration; [3] was associated with a reduced number of small preovulatory follicles; [4] did not cause premature luteinization; [5] resulted in a more estrogenic intrafollicular environment.

Comparison of follicle steroidogenesis from normal and polycystic ovaries in women undergoing IVF: relationship between steroid concentrations, follicle size, oocyte quality and fecundability

Studies of ovarian stimulation for IVF have suggested a relationship between follicle size and pregnancy rates. Furthermore the follicular endocrine environment is correlated with oocyte quality. The aim of this study was first to verify the relationship between follicular steroid content, follicular size, oocyte maturity and fertilization outcome in women with normal ovaries following recombinant human FSH (rhFSH). Secondly this study was extended to women with polycystic ovarian syndrome (PCOS). Fifty-nine patients (31 normal, 28 PCOS) underwent conventional IVF with rhFSH induction. Follicular diameter was classified as small (8-13 mm) or large (>14 mm) and sex steroid content was analysed for each group. Oocyte maturity was studied according to nuclear maturation the day after fertilization. In both ovulation groups, 17 beta-oestradiol and progesterone concentration were significantly higher in large follicles with meiotically competent oocytes compared with those containing meiotically incompetent oocytes. Testosterone levels were increased in PCOS follicles compared with normal patients, with no difference between corresponding sub-groups of follicles with meiotically competent oocytes. The relationship between follicle size and embryo development showed that 14 mm could be a threshold value following rhFSH induction in normal or PCOS women.

Acrosome reaction: methods for detection and clinical significance

The present article reviews the methods for detection and the clinical significance of the acrosome reaction. The best method for the detection of the acrosome reaction is electron microscopy, but it is expensive and labour-intensive and therefore cannot be used routinely. The most widely used methods utilize optical microscopy where spermatozoa are stained for the visualization of their acrosomal status. Different dyes are used for this purpose as well as lectins and antibodies labelled with fluorescence. The acrosome reaction following ionophore challenge (ARIC) can separate spermatozoa that undergo spontaneous acrosome reaction from those that are induced, making the result of the inducible acrosome reaction more meaningful. Many different stimuli have been used for the induction of the acrosome reaction with different results. The ARIC test can provide information on the fertilizing capability of a sample. The ARIC test was also used to evaluate patients undergoing in vitro fertilization since a low percentage of induced acrosome reaction was found to be associated with lower rates of fertilization. The cut-off value that could be used to identify infertile patients is under debate. Therapeutic decisions can also be made on the basis of the value of the ARIC test.

Messenger RNA expression and protein localization of growth hormone in bovine ovarian tissue and in cumulus oocyte complexes (COCs) during in vitro maturation

The aim of this study was to investigate whether bovine cumulus oocyte complexes (COCs) obtained from 2 to 8 mm follicles synthesize growth hormone (GH) during in vitro maturation. In addition the expression of growth hormone releasing hormone receptor (GHRH-r) in the COCs before and after in vitro maturation was investigated. Therefore, COCs obtained from small and medium sized follicles were cultured in M199 supplemented with 10% FCS and gonadotropins for 24 hr. At 0, 6, 12, and 24 hr after the onset of culture, COCs were removed and were prepared for immunohistochemical staining to detect the presence of GH. In addition, sections of ovary were stained to study the differential localization of GH in the ovary. At 0 and 24 hr COCs were removed and together with samples from granulosa cells and theca cells were prepared for reverse transcriptase polymerase chain reaction (RT-PCR) to assess the expression of mRNA of GH and GHRH-r. Within COCs, cumulus cells and oocytes showed GH immunoreactivity, while expression of GH mRNA was only found in the oocyte. At the onset of culture, oocytes and cumulus cells in the majority of COCs generally showed moderate and strong staining intensity for GH, respectively. While GH staining in the cumulus cells did hardly change during 24 hr of culture, GH staining in the oocyte was absent after 24 hr of culture in 70% of COCs. Within the ovary, GH was localized in antral follicles larger than 2 mm and no staining was found in primordial, primary and secondary follicles or in the stroma. The intensity of the staining increased with the size of the follicles. Within the follicular wall the GH was persistently observed in granulosa cells, while theca cells were occasionally negative. GH mRNA in follicular compartments was only found in the oocyte and mural granulosa cells. No GHRH-r mRNA was found in the COCs nor in the granulosa or the stroma. In conclusion, the gradual increase of GH staining during follicular development and the consistent synthesis of GH in oocytes and granulosa cells, suggest a paracrine and/or autocrine action for GH in bovine follicular growth and oocyte maturation. The absence of mRNA for GHRH receptor in the COCs indicates that ovarian production of GH is not regulated by GHRH.

Plasma levels of GH and PRL and concentrations in the fluids of bovine ovarian cysts and follicles

Prolactin and GH have been detected within the ovary, and it has become increasingly evident that they have a role as intrafollicular regulatory factors. The aim of the present work was to gain an insight into the elements influencing intraovarian GH and PRL in bovine species and to see whether cystic degeneration was accompanied by abnormal bovine GH (bGH) and PRL (bPRL) plasma patterns. We followed the relationships between plasma and ovarian fluid bGH and bPRL concentrations over an entire year in Friesian cows whose ovaries showed distinct types of structures. To assess the presence of bGH and bPRL within ovarian cells, we assayed selected ovarian structures by immunohistochemistry. The results demonstrated that: 1) plasma and ovarian fluid hormonal concentrations were independent, and their ratio was independent of the ovarian structure classes, subclasses and period of the year; 2) in the majority of the cows the concentration of bGH in ovarian fluid was no more than 80% of the level in plasma, whereas in about half the animals bPRL concentrations were higher in the ovary than in peripheral plasma; 3) mean bPRL concentrations in ovarian fluids were significantly higher in summer than in winter; 4) immunoreactive bGH and bPRL were present within granulosa and luteal cells. Thus, it is suggested that in the cow bGH and bPRL levels in the ovary might be regulated in some way independently of the pituitary.

Growth hormone but not prolactin concentrations in the fluid of bovine ovarian cysts are related to the cystic stage of luteinization

Regulation of follicular growth and ovulation as well as steroid production by the ovary depends principally on gonadotropins. However nonsteroid systemic hormones and autocrine and paracrine factors contribute to the regulation of ovarian function. The objectives of the present work were 1) to asses the presence of growth hormone (GH) and prolactin (PRL) in fluid drawn from normal bovine ovarian follicles, cysts or cystic corpora lutea; 2) to relate the stage of luteinization of the cyst with the GH and PRL concentrations in fluids; and 3) to asses the feasibility of providing a defined nonsteroid hormone marker to distinguish between normal and pathological ovarian structures. Cysts were classified according to histological and morphological appearance as follicular or luteal. Concentrations of GH, PRL, estrogens (E2), progesterone (P4) and testosterone (T) were measured in follicular and cystic fluids. On the basis of the E2 to P4 ratio, ovarian formation classes were further divided into two subclasses (E2 dominant and P4 dominant). The results provide evidence of 1) the presence of immunoreactive GH and PRL in all the follicular and cystic fluids assayed, 2) an increasing concentration of GH correlated to the stage of luteinization of the cyst and a direct correlation between GH and P4 concentrations, 3) a significant variability of intraovarian fluid PRL concentration not related to the histological class of the cyst nor to the concentrations of steroid hormones examined, and 4) the possibility of distinguishing 6 different ovarian formation classes by merely measuring GH, P4, E2 and T concentrations in fluids. These data contribute to a better understanding of the endocrine milieu of bovine ovarian cystic degeneration.

Effect of follicle size and quality on the ability of follicular fluid to support cytoplasmic maturation of bovine oocytes

Recent studies have shown that the developmental capacity of in vitro-matured oocytes is affected by the origin of follicular fluid (FF) supplemented to the maturation medium. The aims of this study were (1) to determine if follicle size and quality would influence the capacity of FF to support bovine oocyte maturation and (2) to determine if fetal calf serum (FCS) and FF had an additive effect when added together to the maturation medium. Follicular fluid collected from 108 follicles was classified according to size ( < 6, 6-8, > 8 mm in diameter) and quality (healthy, early atretic, and atretic). Quality, first determined by mitosis/pycnosis ratios in granulosa cell smears, was subsequently confirmed by insulin-like growth factor binding protein (IGFBP) patterns and estradiol concentrations. While most small- or medium-sized follicles showed some atresia (88% and 67%, respectively), fewer of the large follicles were atretic (30%). In experiment 1 bovine oocytes (n = 2,152) were matured either in TCM199 alone, with 10% FCS, or with 10% FF from the following follicle types: small healthy (SH); small early atretic (SEA); small atretic (SA); medium healthy (MH); medium early atretic (MEA); medium atretic (MA); large healthy (LH); large early atretic (LEA); and large atretic (LA). Following IVM, oocytes were fertilized and subsequently cultured in synthetic oviduct fluid (SOF). Day 8 blastocyst yields were 23% in TCM199 alone; 37% in TCM199 plus FCS; and, in medium supplemented with FF, SH, 36%; MH, 32%; LH, 30%; SEA, 21%; MEA, 26%; LEA, 28%; SA, 32%; MA, 33%; and LA, 38%. All FF from healthy or atretic follicles resulted in significantly improved blastocyst yields compared to M199 alone (P < 0.05). However, FF from early atretic follicles irrespective of size did not yield a significant improvement. In experiment 2 we examined the effect of addition of FF-LH and serum together to the maturation medium. In terms of blastocyst yield, no additional benefit was observed when TCM199 was supplemented with 10% FCS + 10% FF (33%) compared to 10% FCS or FF alone (35% and 30%, respectively). The efficacy of FF as a supplement to the maturation medium to improve cytoplasmic maturation appears to vary with follicle quality but not size. However, in general, the addition of 10% FF or FCS to the maturation media resulted in a similar blastocyst yield with no additional improvement when media was supplemented with both FCS and FF.

Interleukin-1 beta, interleukin-6, and growth hormone levels in human follicular fluid

PURPOSE

To investigate possible relationships of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and growth hormone (GH) with biochemical variables in human follicular fluid (FF) and selected in vitro fertilization (IVF) parameters.

METHODS

A total of 67 FF samples (n = 67 patients undergoing oocyte retrieval for IVF) was evaluated. IL-1 beta, IL-6, GH, hLH, FSH, PRL, hCG, testosterone, total protein, fibrinogen, sialic acid, alpha 1-antitrypsin, plasminogen levels, and spectrophotometric absorbance at 458 nm were analyzed for selected FF. IL-6 and GH levels of serum and FF samples were also compared (n = 23).

RESULTS

Immunoreactive levels of IL-1 beta, IL-6, and GH were detected in all FF samples. A positive correlation existed for IL-6 (r = 0.5069, P = 0.0161) when serum-to-FF levels were compared (concentration ratio, 1:1.857). Smaller-volume follicles (< 4 ml) were associated with high IL-1 beta levels (P = 0.0229), and an additional tendency of IL-1 beta to decrease with increasing embryo cleavage and scoring was observed. With the exception of a weak positive correlation between follicular IL-1 beta and testosterone levels (r = 0.3128, P = 0.025), no other relationship with biochemical variables or IVF parameters (etiology, e.g., endometriosis) could be implicated.

CONCLUSIONS

Substantially higher IL-6 levels occurred in FF compared to serum, thus supporting intrafollicular production. Interleukin-1 beta, IL-6, and GH levels in FF are, however, unsuitable markers for in vitro fertilization outcome.