Serum and follicular endocrine profile is different in modified natural cycles than in cycles stimulated with gonadotropin and gonadotropin-releasing hormone antagonist

Risk factors for low oocyte retrieval in patients with polycystic ovarian syndrome undergoing in vitro fertilization

BACKGROUND

The number of oocytes retrieved does not always coincide with the number of follicles aspirated in in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment. Patients with high expectation of retrieval sometimes obtain few oocytes, which may be induced by improper operation or therapeutic factors. The purpose of this study was to evaluate the distribution data of oocyte retrieval rate (ORR) and to explore the risk factors for low ORR in patients with polycystic ovary syndrome (PCOS) undergoing IVF/ICSI.

METHODS

A total of 2478 patients with PCOS undergoing IVF/ICSI were involved in this retrospective case-control study from March 2016 to October 2021. The oocyte retrieval rate was calculated as the ratio of the number of obtained oocytes to the number of follicles (≥ 12 mm) on the trigger day. Patients were divided into a low ORR and a normal ORR group with the boundary of one standard deviation from the mean value of ORR. The patient characteristics, treatment protocols, serum hormone levels, and embryonic and pregnancy outcomes were analyzed.

RESULTS

The ORR exhibited a non-normal distribution, with a median of 0.818. The incidence of complete empty follicle syndrome was 0.12% (3/2478). The proportion of patients in the low ORR group who received the progestin-primed protocol was significantly higher than that in the normal ORR group (30.30% vs. 17.69%). A logistic regression analysis showed that the serum estradiol level/follicle (≥ 12 mm) ratio (OR: 0.600 (0.545-0.661)) and progesterone level (OR: 0.783 (0.720-0.853)) on the trigger day were significant factors in the development of a low ORR, with optimal cutoff values of 172.85 pg/ml and 0.83 ng/ml, respectively, as determined by receiver operating curve. Fewer high-quality embryos (2 vs. 5) and more cycles with no available embryos (5.42% vs. 0.43%) were found in the low ORR group.

CONCLUSIONS

For patients with PCOS, low estradiol levels/follicles (≥ 12 mm) and progesterone levels on the trigger day and the use of the progestin-primed protocol could be risk factors for low ORR, which leads to a limited number of embryos and more cycle cancellations.

Gonadotropin Stimulation Has Only a Limited Effect on the Concentration of Follicular Fluid Signalling Proteins: An Antibody Array Analysis

Objective

The follicular fluid (FF) plays an essential role in the physiology of the follicle and the oocyte. Gonadotropin stimulation affects the FF steroid hormone and anti-Mullerian hormone (AMH) concentrations, which has been suggested to be the reason for lower oocyte competence in conventional gonadotropin stimulated in vitro fertilisation (cIVF) compared to natural cycle IVF (NC-IVF). To analyse the effect of gonadotropin stimulation on a broad spectrum of signalling proteins, we ran proteomic antibody arrays on FF of women undergoing both treatments NC-IVF and cIVF.

Method

Twenty women underwent one NC-IVF and one cIVF treatment cycle. Follicular fluids of the first aspirated follicle were compared between the two groups using a protein microarray which included antibodies against 224 proteins related to cell signalling and reference proteins. Each of the 40 albumin-stripped, matched-pair samples was labelled in the reverse-dye (Cy3/Cy5) procedure before undergoing array hybridisation. Signal analysis was performed using normalisation algorithms in dedicated software. Five proteins yielding a value of P < 0.05 in the array experiment (Cystatin A, Caspase-3, GAD65/67, ERK-1, and ERK-2) were then submitted to quantitative determination by ELISA in the same follicular fluids.

Results

Array analysis yielded only a small number of differentially expressed signalling markers by unadjusted P values. Adjustment as a consequence of multiple determinations resulted in the absence of any significant differential marker expression on the array. Five unadjusted differentially expressed proteins were quantified immunometrically with antibodies from different sources. Follicular fluid concentrations of Cystatin A and MAP kinase ERK-1 concentrations were significantly higher in the cIVF than in the NC-IVF follicles, while GAD-2 (GAD65/67) did not differ. The assays for Caspase-3 and MAP kinase ERK-2 did not have the required sensitivities.

Conclusion

In contrast to FF steroid hormones and AMH, FF concentrations of signalling proteins are not or only marginally altered by gonadotropin stimulation.

Steroid metabolome profiling of follicular fluid in normo- and hyperandrogenic women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous disease defined by the presence of at least two of the following features: hyperandrogenism, oligoanovulation (OA), and polycystic ovarian morphology (PCOM). Hyperandrogenism is considered the cornerstone of PCOS. However, the most prevalent phenotype in Chinese women with PCOS is OA + PCOM [normo-androgenic PCOS (NA-PCOS)]. It has been reported that PCOS women have higher androgen levels in follicular fluid (FF), but whether NA-PCOS women have the same intrafollicular steroid profiles as hyperandrogenic PCOS (HA-PCOS) women has not been explored. In this study, we analyzed 17 steroids in stimulated size-matched ovarian follicles (16-18 mm) from 166 controls and 141 PCOS women [87 NA-PCOS and 54 HA-PCOS women, defined by a single serum testosterone (T) immunoassay measurement] using liquid chromatography tandem mass spectrometry, and investigated their relationship with baseline characteristics. No significant differences in intrafollicular steroid levels and product/precursor ratios between NA-PCOS and HA-PCOS women were observed, though HA-PCOS women had significantly higher serum luteinizing hormone and T levels than NA-PCOS women. NA-PCOS and HA-PCOS women had significantly higher levels of androstenedione (AD), T and free androgen index, higher enzyme activity of P450c17 (AD/17OH-progesterone), 3βHSD2 (17OH-progesterone /17OH-pregnenolone) and P450c11 (corticosterone /11-deoxycorticosterone), lower levels of pregnenolone, 17OH-pregnenolone and 11-deoxycorticosterone, and decreased enzyme activity of P450aro (estrone/AD and estradiol/T) and 5α-reductase (dihydrotestosterone/T) in FF than controls. NA-PCOS women had significantly higher intrafollicular cortisol levels and lower 11βHSD2 (cortisone/cortisol) activity than controls. Baseline serum T levels were slightly correlated with intrafollicular estrogens (E1: r = 0.192, p = 0.019; E2: r = 0.248, p = 0.002; E3: r = 0.248, p = 0.002) and androgens (DHEAS: r = 0.276, p = 0.001; AD: r = 0.185, p = 0.032; T: r = 0.173, p = 0.044) in controls and PCOS women respectively. Serum anti-Müllerian hormone (AMH) levels and antral follicle count (AFC) were correlated with intrafollicular cortisol (AMH: r = 0.380, p = 0.000; AFC: r = 0.177, p = 0.036) and corticosterone (AMH: r = 0.212, p = 0.048; AFC: r = 0.219, p = 0.009) levels in PCOS women. In conclusion, NA-PCOS and HA-PCOS women had statistically similar steroid metabolome profiles in FF, both of which showed a generally decreased steroidogenesis and hyperandrogenism compared to controls.

Oocyte matched follicular fluid anti-Müllerian hormone is an excellent predictor of live birth after fresh single embryo transfer

STUDY QUESTION

What is the relationship between the anti-Müllerian hormone (AMH), gonadotropin and androgen concentrations within a single follicle and live birth after ICSI and a transfer of an embryo developed from the matched oocyte?

SUMMARY ANSWER

Among the analysed markers on the day of oocyte retrieval, AMH concentration in follicular fluid (FF) is a predictor of live birth after single embryo transfer (SET).

WHAT IS KNOWN ALREADY

High serum concentrations of AMH and low FSH concentrations have been associated with a high chance of pregnancy after ART. Whether there are differences in the hormonal milieu for individual follicles and whether this impacts the laboratory and clinical outcomes for the individual oocyte developing within that follicle are unknown.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study included 322 individual FF samples from 199 infertile women scheduled for ICSI/SET over an 18-month period. Of these women, 76 provided a single FF sample, while 123 women contributed two FF samples taken from two different follicles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The first follicle aspirated in each ovary on the day of oocyte retrieval had the FF aspirated; the individual cumulus-oocyte complex (COC) was tracked, and the associated FF was stored at -80°C. FF AMH, FSH, LH, testosterone (T) and androstenedione (A2) levels were measured by mass spectrometry (androgens) and immunoassays. The laboratory and clinical outcomes for each individual oocyte were related to their unique follicle hormone concentrations.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 322 oocytes with paired FF samples, 70 (21.7%) oocytes did not fertilise. From the remaining 252 2PN embryos, 88 (34.9%) were transferred as single embryos on Day 3; of the remaining 164, 78 developed into blastocysts, and 18 single blastocyst transfers were performed. Thus, a total of 106 transferred embryos had matching FF samples. An analysis of these individual FF concentrations revealed that AMH concentrations were higher in follicles in which the oocyte developed into a top quality (TQ) blastocyst (6.33 ± 5.52 ng/ml) and whose transfer led to live birth (7.49 ± 5.03 ng/ml) than those in which there was a failure of fertilisation (3.34 ± 2.21 ng/ml). In contrast, follicular FSH concentrations were the lower for oocytes that resulted in a TQ blastocyst (5.36 ± 2.20 mIU/ml) and live birth (5.60 ± 1.41 mIU/ml) than for oocytes that failed to fertilise (9.06 ± 3.36 mIU/ml). FF AMH was the only studied marker that increased the chance of live birth (odds ratio: 1.93 [95% CI: 1.40-2.67], P < 0.001). The receiver operating characteristic analysis showed that FF AMH levels predicted live birth with a very high sensitivity (91.2%), specificity (91.7%) and an excellent AUC value of 0.954, whereas serum AMH level only had a fair (AUC = 0.711) significance as a predictor for live birth after ICSI/SET. The predictive capabilities of the interfollicular markers were not limited to the TQ embryos or blastocysts; they applied to all SET cycles.

LIMITATIONS, REASONS FOR CAUTION

Whether an altered intrafollicular hormonal environment reflects the developmental capacity of the oocyte or defines cannot be determined from this cross-sectional analysis. Inclusion of 21 subjects with polycystic ovary syndrome (PCOS) may have biased the findings due to a unique intrafollicular milieu associated with PCOS.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that highly competent human oocytes have an FF composition of AMH, FSH, T and A2 that is close to that in a natural cycle. Also, the relationships between intrafollicular AMH, gonadotropin and androgen levels in the same follicle support the hypothesis that FF AMH concentration may reflect granulosa cell proliferation during gonadotropin-stimulated follicle growth. Finally, the serum AMH concentration is markedly lower than the FF AMH concentration, with a moderate correlation between serum and FF AMH, implying ovarian follicle autonomy with regards to its secretory products.

STUDY FUNDING/COMPETING INTEREST(S)

The National Science Centre of Poland supported this work (grant number: N N407 217 040). The authors declare that there is no conflict of interest regarding the publication of this article.

Oocyte environment: follicular fluid and cumulus cells are critical for oocyte health

Bidirectional somatic cell-oocyte signaling is essential to create a changing intrafollicular microenvironment that controls primordial follicle growth into a cohort of growing follicles, from which one antral follicle is selected to ovulate a healthy oocyte. Such intercellular communications allow the oocyte to determine its own fate by influencing the intrafollicular microenvironment, which in turn provides the necessary cellular functions for oocyte developmental competence, which is defined as the ability of the oocyte to complete meiosis and undergo fertilization, embryogenesis, and term development. These coordinated somatic cell-oocyte interactions attempt to balance cellular metabolism with energy requirements during folliculogenesis, including changing energy utilization during meiotic resumption. If these cellular mechanisms are perturbed by metabolic disease and/or maternal aging, molecular damage of the oocyte can alter macromolecules, induce mitochondrial mutations, and reduce adenosine triphosphate production, all of which can harm the oocyte. Recent technologies are now exploring transcriptional, translational, and post-translational events within the human follicle with the goal of identifying biomarkers that reliably predict oocyte quality in the clinical setting.

Follicular fluid anti-Müllerian hormone: a predictive marker of fertilization capacity of MII oocytes

PURPOSE

The present study aimed to correlate anti-Müllerian hormone (AMH) levels in follicular fluid (FF) with oocyte maturity stages, morphological quality of metaphase II (MII) oocyte and fertilization capacity of MII oocytes.

METHODS

A total of 92 infertile women undergoing controlled ovarian stimulation and intracytoplasmic sperm injection were analyzed. Patients were divided into two groups according to age: <35 years (n = 43) and ≥35 years (n = 49). An FF sample was obtained from a single dominant follicle in each patient for a total of 92 follicular fluid samples analyzed. AMH levels in serum and follicular fluid were measured by enzyme-linked immunosorbent assay. Mature MII oocytes, zygotes, and embryos were assessed for morphological quality.

RESULTS

Serum AMH levels were significantly higher in patients aged <35 years. No correlation was observed between FF AMH level and oocyte maturation stages or morphological quality of MII oocyte. Significantly lower FF AMH levels were observed in fertilized MII oocytes than in non-fertilized MII oocytes in patients aged <35 years (2.56 ± 2.0 ng/ml vs. 4.81 ± 4.14 ng/ml; p = 0.032).

CONCLUSIONS

The present study revealed no correlation between FF AMH and oocyte maturity stage or morphological quality of MII oocyte. However, FF AMH might be a predictive marker for fertilization capacity of MII oocytes.

Differences in cumulus cells gene expression between modified natural and stimulated in vitro fertilization cycles

PURPOSE

The aim of our study was to determine whether there are any differences in the cumulus cell gene expression profile of mature oocytes derived from modified natural IVF and controlled ovarian hyperstimulation cycles and if these changes could help us understand why modified natural IVF has lower success rates.

METHODS

Cumulus cells surrounding mature oocytes that developed to morulae or blastocysts on day 5 after oocyte retrieval were submitted to microarray analysis. The obtained data were then validated using quantitative real-time PCR.

RESULTS

There were 66 differentially expressed genes between cumulus cells of modified natural IVF and controlled ovarian hyperstimulation cycles. Gene ontology analysis revealed the oxidation-reduction process, glutathione metabolic process, xenobiotic metabolic process and gene expression were significantly enriched biological processes in MNIVF cycles. Among differentially expressed genes we observed a large group of small nucleolar RNA's whose role in folliculogenesis has not yet been established.

CONCLUSION

The increased expression of genes involved in the oxidation-reduction process probably points to hypoxic conditions in modified natural IVF cycles. This finding opens up new perspectives for the establishment of the potential role that oxidation-reduction processes have in determining success rates of modified natural IVF.

Natural cycle in vitro fertilisation (IVF) for subfertile couples

BACKGROUND

Subfertility affects 15% to 20% of couples trying to conceive. In vitro fertilisation (IVF) is one of the assisted reproduction techniques developed to improve chances of achieving pregnancy. In the standard IVF method with controlled ovarian hyperstimulation (COH), growth and development of multiple follicles are stimulated by using gonadotrophins, often combined with a gonadotrophin-releasing hormone (GnRH) agonist or antagonist. Although it is an established method of conception for subfertile couples, the treatment is expensive and has a high risk of adverse effects. Studies have shown that IVF in a natural cycle (NC) or a modified natural cycle (MNC) might be a promising low risk and low cost alternative to the standard stimulated IVF treatment since the available dominant follicle of each cycle is used. In this review, we included available randomised controlled studies comparing natural cycle IVF (NC and MNC) with standard IVF.

OBJECTIVES

To compare the efficacy and safety of natural cycle IVF (including both NC-IVF and MNC-IVF) with controlled ovarian hyperstimulation IVF (COH-IVF) in subfertile couples.

SEARCH METHODS

An extended search including of the Menstrual Disorders and Subfertility Group (MDSG) Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, ClinicalTrials.gov, conference abstracts in the Web of Knowledge, the World Health Organization International Trials Registry Platform search portal, LILACS database, PubMed and the OpenSIGLE database was conducted according to Cochrane guidelines. The last search was on 31st July 2013.

SELECTION CRITERIA

All randomised controlled trials (RCTs) comparing either natural cycle IVF or modified natural cycle IVF versus standard IVF in subfertile couples were included.

DATA COLLECTION AND ANALYSIS

Data selection and extraction and risk of bias assessment were carried out independently by two authors (TA and AC). The primary outcome measures were live birth rate and ovarian hyperstimulation syndrome (OHSS) rate per randomised woman. We calculated Mantel-Haenszel odds ratios for each dichotomous outcome and either the mean difference or the standardised mean difference (SMD) for continuous outcomes, with 95% confidence intervals (CIs). A fixed effect model was used unless there was substantial heterogeneity, in which case a random effects model was used.

MAIN RESULTS

Six randomised controlled trials with a total of 788 women were included. The largest of these trials included 396 women eligible for this review.No evidence of a statistically significant difference was found between natural cycle and standard IVF in live birth rates (OR 0.68, 95% CI 0.46 to 1.01, two studies, 425 women, I(2)= 0%, moderate quality evidence). The evidence suggests that for a woman with a 53% chance of live birth using standard IVF, the chance using natural cycle IVF would range from 34% to 53%. There was no evidence of a statistically significant difference between natural cycle and standard IVF in rates of OHSS (OR 0.19, 95% CI 0.01 to 4.06, one study, 60 women, very low quality evidence), clinical pregnancy (OR 0.52 95% CI 0.17 to 1.61, 4 studies, 351 women, I(2)=63%, low quality evidence), ongoing pregnancy (OR 0.72, 95% CI 0.50 to 1.05, three studies, 485 women, I(2)=0%, moderate quality evidence), multiple pregnancy (OR 0.76, 95% CI 0.25 to 2.31, 2 studies, 527 women, I(2)=0%, very low quality evidence), gestational abnormalities (OR 0.44 95% CI 0.03 to 5.93, 1 study, 18 women, very low quality evidence) or cycle cancellations (OR 8.98, 95% CI 0.20 to 393.66, 2 studies, 159 women, I(2)=83%, very low quality evidence). One trial reported that the oocyte retrieval rate was significantly lower in the natural cycle group (MD -4.40, 95% CI -7.87 to -0.93, 60 women, very low quality evidence). There were insufficient data to draw any conclusions about rates of treatment cancellation. Findings on treatment costs were inconsistent and more data are awaited. The evidence was limited by imprecision. Findings for pregnancy rate and for cycle cancellation were sensitive to the choice of statistical model: for these outcomes, use of a fixed effect model suggested a benefit for the standard IVF group. Moreover the largest trial has not yet completed follow up, though data have been reported for over 95% of women.

AUTHORS' CONCLUSIONS

Further evidence from well conducted large trials is awaited on natural cycle IVF treatment. Future trials should compare natural cycle IVF with standard IVF. Outcomes should include cumulative live birth and pregnancy rates, the number of treatment cycles necessary to reach live birth, treatment costs and adverse effects.