Follicle-Stimulating Hormone Affects Metaphase I Chromosome Alignment and Increases Aneuploidy in Mouse Oocytes Matured in Vitro1

Effects of total gonadotropin dose on embryo quality and clinical outcomes with AMH stratification in IVF cycles: a retrospective analysis of 12,588 patients

BACKGROUND

Recent studies about the effect of gonadotropin (Gn) dose on the clinical outcomes of IVF are still controversial, and no studies have analyzed the relationship between Gn dose and embryo quality. Since AMH is a strong predictor of oocyte quality, we aim to evaluate the relationship between total Gn dose and embryo quality and clinical outcomes at different AMH levels in IVF cycles.

METHODS

A total of 12,588 patients were enrolled in the retrospective study. The included cycles were categorized by serum AMH levels (AMH ≤ 1 ng/ml, 1 ng/ml < AMH ≤ 3 ng/ml, 3 ng/ml < AMH ≤ 5 ng/ml, AMH > 5 ng/ml), total Gn dosage (< 1875 IU, 1875-3750 IU and ≥ 3750 IU) and female age (< 35 years and 35-42 years). The embryo quality and clinical outcomes were the measure outcomes.

RESULTS

The top-day3 embryos rate decreased with the increase of total Gn dose in nearly all age and AMH subgroups, but this trend was not obvious in the AMH > 5 ng/ml group and AMH ≤ 1 ng/ml group. The blastocyst formation rate and high-quality blastulation rate had a negative relationship with Gn does for women aged < 35 years in the AMH ≤ 5 ng/ml groups, except for the AMH > 5 ng/ml group (P < 0.001). However, when women were 35-42 years old, regardless of AMH levels, the blastocyst formation rate and high-quality blastulation rate decreased as Gn dose increased. Clinical outcomes (implantation rate, clinical pregnancy rate and live birth rate) decreased with the increase of Gn dose in all ages and AMH stratifications.

CONCLUSIONS

The total dose of Gn may have different effects on embryo quality at different serum AMH levels, and the negative effects of total dose of Gn on clinical outcomes may be realized by impairing both embryo quality and endometrium.

Nonlinear relationship between gonadotropin total dose applied and live birth rates in non-PCOS patients: a retrospective cohort study

The purpose of this article is to explore the relationship between the total dose of follicle-stimulating hormone (FSH) applied during controlled ovulation stimulation and the live birth rates (LBRs) in non-PCOS population. Many studies have found no difference between the dose of FSH application and pregnancy outcomes such as clinical pregnancy rates after fresh embryo transfer. However, a recent large retrospective analysis found a negative correlation between live birth rates and increasing dose of FSH. It is still controversial about the association between FSH dose and LBRs. In addition, no studies have yet explored the nonlinear relationship between FSH and LBRs. This cohort study included a total of 11,645 patients who had accepted IVF/intracytoplasmic sperm injection (ICSI) at the second hospital of Hebei medical university between December 2014 to December 2019. PCOS was identified by Rotterdam PCOS criteria. We researched the association between FSH total dose and live birth rates (LBRs) using multivariate regression analysis. In addition, a model for nonlinear relationships based on a two-part linear regression was applied. The analysis of threshold effects indicated that LBR increased with every 1000 IU FSH when the concentration of FSH was lower than 1410 IU (OR 1.55, 95% CI [1.05, 2.28]); however, a negative association between FSH dose and LBR (OR 0.94, 95% CI [0.89, 0.99]) was found when the FSH total dose was higher than 1410 IU. It is worth noting that the relationship between LBR and FSH dose varied among patients of different ages (OR 0.92 vs 1.06, P for interaction < 0.05).

Individualised gonadotropin dose selection using markers of ovarian reserve for women undergoing in vitro fertilisation plus intracytoplasmic sperm injection (IVF/ICSI)

BACKGROUND

During a stimulated cycle of in vitro fertilisation or intracytoplasmic sperm injection (IVF/ICSI), women receive daily doses of gonadotropin follicle-stimulating hormone (FSH) to induce multifollicular development in the ovaries. A normal response to stimulation (e.g. retrieval of 5 to 15 oocytes) is considered desirable. Generally, the number of eggs retrieved is associated with the dose of FSH. Both hyper-response and poor response are associated with an increased chance of cycle cancellation. In hyper-response, this is due to increased risk of ovarian hyperstimulation syndrome (OHSS), while poor response cycles are cancelled because the quantity and quality of oocytes is expected to be low. Clinicians often individualise the FSH dose using patient characteristics predictive of ovarian response. Traditionally, this meant women's age, but increasingly, clinicians use various ovarian reserve tests (ORTs). These include basal FSH (bFSH), antral follicle count (AFC), and anti-Müllerian hormone (AMH). It is unclear whether individualising FSH dose improves clinical outcomes. This review updates the 2018 version.

OBJECTIVES

To assess the effects of individualised gonadotropin dose selection using markers of ovarian reserve in women undergoing IVF/ICSI.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Specialised Register of controlled trials, CENTRAL, MEDLINE, Embase, and two trial registers in February 2023.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared (a) different doses of FSH in women with a defined ORT profile (i.e. predicted low, normal, or high responders based on AMH, AFC, and/or bFSH) or (b) an individualised dosing strategy (based on at least one ORT measure) versus uniform dosing or a different individualised dosing algorithm.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Primary outcomes were live birth/ongoing pregnancy and severe OHSS.

MAIN RESULTS

We included 26 studies, involving 8520 women (6 new studies added to 20 studies included in the previous version). We treated RCTs with multiple comparisons as separate trials for the purpose of this review. Meta-analysis was limited due to clinical heterogeneity. Evidence certainty ranged from very low to low, with the main limitations being imprecision and risk of bias associated with lack of blinding. Direct dose comparisons according to predicted response in women Due to differences in dose comparisons, caution is required when interpreting the RCTs in predicted low responders. All evidence was low or very low certainty. Effect estimates were very imprecise, and increased FSH dosing may or may not have an impact on rates of live birth/ongoing pregnancy, OHSS, and clinical pregnancy. Similarly, in predicted normal responders (10 studies, 4 comparisons), higher doses may or may not impact the probability of live birth/ongoing pregnancy (e.g. 200 versus 100 international units (IU): odds ratio (OR) 0.88, 95% confidence interval (CI) 0.57 to 1.36; I2 = 0%; 2 studies, 522 women) or clinical pregnancy. Results were imprecise, and a small benefit or harm remains possible. There were too few events for the OHSS outcome to enable inferences. In predicted high responders, lower doses may or may not affect live birth/ongoing pregnancy (OR 0.98, 95% CI 0.66 to 1.46; 1 study, 521 women), severe OHSS, and clinical pregnancy. It is also unclear whether lower doses reduce moderate or severe OHSS (Peto OR 2.31, 95% CI 0.80 to 6.67; 1 study, 521 participants). ORT-algorithm studies Eight trials compared an ORT-based algorithm to a non-ORT control group. It is unclear whether live birth/ongoing pregnancy and clinical pregnancy are increased using an ORT-based algorithm (live birth/ongoing pregnancy: OR 1.12, 95% CI 0.98 to 1.29; I2 = 30%; 7 studies, 4400 women; clinical pregnancy: OR 1.04, 95% CI 0.91 to 1.18; I2 = 18%; 7 studies, 4400 women; low-certainty evidence). However, ORT algorithms may reduce moderate or severe OHSS (Peto OR 0.60, 95% CI 0.42 to 0.84; I2 = 0%; 7 studies, 4400 women; low-certainty evidence). There was insufficient evidence to determine whether the groups differed in rates of severe OHSS (Peto OR 0.74, 95% CI 0.42 to 1.28; I2 = 0%; 5 studies, 2724 women; low-certainty evidence). Our findings suggest that if the chance of live birth with a standard starting dose is 25%, the chance with ORT-based dosing would be between 25% and 31%. If the chance of moderate or severe OHSS with a standard starting dose is 5%, the chance with ORT-based dosing would be between 2% and 5%. These results should be treated cautiously due to heterogeneity in the algorithms: some algorithms appear to be more effective than others.

AUTHORS' CONCLUSIONS

We did not find that tailoring the FSH dose in any particular ORT population (low, normal, high ORT) affected live birth/ongoing pregnancy rates, but we could not rule out differences, due to sample size limitations. Low-certainty evidence suggests that it is unclear if ORT-based individualisation leads to an increase in live birth/ongoing pregnancy rates compared to a policy of giving all women 150 IU. The confidence interval is consistent with an increase of up to around six percentage points with ORT-based dosing (e.g. from 25% to 31%) or a very small decrease (< 1%). A difference of this magnitude could be important to many women. It is unclear if this is driven by improved outcomes in a particular subgroup. Further, ORT algorithms reduced the incidence of OHSS compared to standard dosing of 150 IU. However, the size of the effect is also unclear. The included studies were heterogeneous in design, which limited the interpretation of pooled estimates. It is likely that different ORT algorithms differ in their effectiveness. Current evidence does not provide a clear justification for adjusting the dose of 150 IU in poor or normal responders, especially as increased dose is associated with greater total FSH dose and cost. It is unclear whether a decreased dose in predicted high responders reduces OHSS, although this would appear to be the most likely explanation for the results.

Thiol-yne click crosslink hyaluronic acid/chitosan hydrogel for three-dimensional in vitro follicle development

There is a great deal of potential for in vitro follicle growth to provide an alternative approach to fertility preservation. This strategy reduces the possibility of cancer cells re-exposure after transplantation, and it does not require hormone stimulation. Adopting a three-dimensional (3D) culture method helps preserve the architecture of the follicle and promotes the maturity of oocytes. In order to maintain follicle morphology, enhance the quality of mature oocytes, and facilitate meiotic spindle assembly, the current work aimed to develop the 3D in vitro preantral mouse follicle culture method. Thiolated chitosan-co-thiolated hyaluronic (CSHS) hydrogel was designed to evaluate the effects of biomaterials on ovarian follicle development. Isolated follicles from mouse ovaries were randomly divided into alginate (Alg) as a 3D control, thiolated hyaluronic acid (HASH), and CSHS groups. Single follicle was encapsulated in each hydrogel, and performed for 10 days and subsequently ovulated to retrieve mature oocytes on day 11. CSHS hydrogel promoted follicle survival and oocyte viability with maintained spherical morphology of follicle. Matured oocytes with normal appearance of meiotic spindle and chromosome alignment were higher in the CSHS group compared with those in the Alg and HASH groups. Furthermore, CSHS increased expression level of folliculogenesis genes (TGFβ-1, GDF-9) and endocrine-related genes (LHCGR, and FSHR). With various experimental setups and clinical applications, this platform could be applied as an alternative method to in vitro follicle culture with different experimental designs and clinical applications in the long-term period.

Synergistic effects of follicle-stimulating hormone and epidermal growth factor on in vitro maturation and parthenogenetic development of red-rumped agouti oocytes

Although oocyte in vitro maturation (IVM) is routinely used for in vitro embryo production in mice and rats, its use in wild rodents remains unexplored. Evidence suggests that hormone and growth factor supplementation influence oocyte meiotic resumption. This study evaluated the synergistic effects of follicle-stimulating hormone (FSH) and epidermal growth factor (EGF) on the IVM and parthenogenetic development of red-rumped agouti oocytes. Initially, we evaluated the IVM rates, mature oocyte quality, oocyte morphometry, and early embryonic development during IVM in the presence of 10, 50, and 75 mIU/mL FSH. No differences among the FSH concentrations were observed for IVM rates, oocyte morphometry, cumulus cell expansion, and viability. Although oocytes matured with 50 mIU/mL FSH showed a higher rate of cumulus expansion index (CEI), only oocytes matured with 10 mIU/mL FSH resulted in morulae after chemical activation (7.9% ± 4.2%). Thus, 10 mIU/mL FSH was used for further experiments. We subsequently evaluated the synergistic effects of 10, 50, and 100 ng/mL EGF and 10 mIU/mL FSH on the same parameters. No differences among the groups were observed in IVM rates, oocyte morphometry, and cumulus viability. Nevertheless, FSH with 10 ng/mL EGF showed a CEI superior to that of the other groups. Furthermore, oocytes matured with FSH alone or with both FSH and 10 or 50 ng/mL EGF developed morulae after activation (5.8%-8.3%). In conclusion, oocytes matured with 10 mIU/mL FSH and 10 ng/mL EGF are recommended for use in red-rumped agouti oocyte IVM, as they positively influence embryonic development.

Evaluation of Clinical Outcomes after Poor-Quality Embryo Transfer and Prognostic Parameters

We aimed to investigate the clinical results following poor-quality embryo transfer and the parameters to foresee the prognosis. In this study, 2123 cycles that had day 3 and day 5 single-fresh embryo with poor-quality embryo transfers and good-quality embryo transfers were compared. The cycles according to transfer day were evaluated by conducting a subgroup analysis. The correlation between all the obtained demographic characteristics, controlled ovarian stimulation parameters, and cycle results were analysed. Clinical pregnancy was established in 53 patients that underwent transfer in the poor-quality embryo group (14.9%). Of these patients, 36 had live birth (live birth rate per clinical pregnancy 67.9%). In cleavage-stage embryos, live birth rates per clinical pregnancy were higher in poor-quality blastocyst transfer. When analysing the factors affecting live births in the poor-quality embryo group, as the total gonadotropin dose increases, the probability of live birth decreases, as in the probability of hCG positivity. In conclusion, although the probability of pregnancy is low, when clinical pregnancy is established, there is a high chance of having a live birth after poor-quality embryo transfers. This could be regarded as an acceptable option in cycles when only poor-quality embryos are available.

The effect of peak serum estradiol level during ovarian stimulation on cumulative live birth and obstetric outcomes in freeze-all cycles

Objective

To determine whether the peak serum estradiol (E2) level during ovarian stimulation affects the cumulative live birth rate (CLBR) and obstetric outcomes in freeze-all cycles.

Methods

This retrospective cohort study involved patients who underwent their first cycle of in vitro fertilization followed by a freeze-all strategy and frozen embryo transfer cycles between January 2014 and June 2019 at a tertiary care center. Patients were categorized into four groups according to quartiles of peak serum E2 levels during ovarian stimulation (Q1-Q4). The primary outcome was CLBR. Secondary outcomes included obstetric and neonatal outcomes of singleton and twin pregnancies. Poisson or logistic regression was applied to control for potential confounders for outcome measures, as appropriate. Generalized estimating equations were used to account for multiple cycles from the same patient for the outcome of CLBR.

Results

A total of 11237 patients were included in the analysis. Cumulatively, live births occurred in 8410 women (74.8%). The live birth rate (LBR) and CLBR improved as quartiles of peak E2 levels increased (49.7%, 52.1%, 54.9%, and 56.4% for LBR; 65.1%, 74.3%, 78.4%, and 81.6% for CLBR, from the lowest to the highest quartile of estradiol levels, respectively, P<0.001). Such association remained significant for CLBR after accounting for potential confounders in multivariable regression models, whereas the relationship between LBR and peak E2 levels did not reach statistical significance. In addition, no significant differences were noticed in adverse obstetric and neonatal outcomes (gestational diabetes mellitus, pregnancy-induced hypertension, preeclampsia, placental disorders, preterm birth, low birthweight, and small for gestational age) amongst E2 quartiles for either singleton or twin live births, both before and after adjustment.

Conclusion

In freeze-all cycles, higher peak serum E2 levels during ovarian stimulation were associated with increased CLBR, without increasing the risks of adverse obstetric and neonatal outcomes.

E2/ER signaling mediates the meiotic arrest of goat intrafollicular oocytes induced by follicle-stimulating hormone

The increased production of high-quality oocytes lies at the heart of the search to accelerate the reproduction of high-quality breeding livestock using assisted reproductive technology. Follicle-stimulating hormone (FSH) maintains the arrest of oocyte meiosis during early follicular development in vivo and promotes the synchronous maturation of nucleus and cytoplasm to improve oocyte quality. However, the mechanism by which FSH maintains meiotic arrest in oocytes is still not fully understood. Oocytes spontaneously resume meiosis once released from the arrested state. In this study, we isolated goat antral follicles with a diameter of 2.0-4.0 mm, cultured them in vitro either with or without added FSH, and finally collected the oocytes to observe their meiotic state. The results showed that FSH effectively inhibited the meiotic recovery of oocytes in follicles [4 h: control (n = 84) vs. with FSH (n = 86), P = .0115; 6 h: control (n = 86) vs. FSH (n = 85), P = 0.0308; and 8 h: control (n = 95) vs. FSH (n = 101), P = 0.0039]. FSH significantly inhibited the downregulation of natriuretic peptide receptor 2 (NPR2) expression and cyclic guanosine monophosphate (cGMP) synthesis during follicular culture in vitro (P < 0.05). Further exploration found that FSH promoted the synthesis of 17β-estradiol (E2) (P = .0249 at 4 h and P = .0039 at 8 h) and maintained the expression of the estrogen nuclear receptor ERβ, but not the estrogen nuclear receptor ERα during follicle culture in vitro (P = .0190 at 2 h, and P = .0100 at 4 h). In addition, E2/ER (estrogen nuclear receptors ERα and ERβ) mediated the inhibitory effect of FSH on the downregulation of NPR2 expression and cGMP synthesis, ultimately preventing the meiotic recovery of oocytes (P < .05). In summary, our study showed that FSH-induced estrogen production in goat follicles, and the E2/ER signaling pathway, both mediated meiotic arrest in FSH-induced goat oocytes.

The effect of ovarian stimulation on aneuploidy of early aborted tissues and preimplantation blastocysts: comparison of the GnRH agonist long protocol with the GnRH antagonist protocol

PURPOSE

To compare aneuploidy rates in early aborted tissues or blastocysts between in vitro fertilization (IVF) cycles after the gonadotropin-releasing hormone (GnRH) antagonist (GnRH-ant) protocol or the GnRH agonist (GnRH-a) long protocol.

METHODS

This was a retrospective cohort study from a university-affiliated fertility center. In total, 550 early miscarriage patients who conceived through IVF/intracytoplasmic sperm injection (ICSI) after receiving the GnRH-ant or GnRH-a long protocol were analyzed to compare aneuploidy rates in early aborted tissues. To compare aneuploidy rates in blastocysts, 404 preimplantation genetic testing for aneuploidy (PGT-A) cycles with the GnRH-ant protocol or GnRH-a long protocol were also analyzed.

RESULTS

For early miscarriage patients who conceived through IVF/ICSI, compared to the GnRH-a long protocol group, the GnRH-ant protocol group had a significantly higher rate of aneuploidy in early aborted tissues (48.51% vs. 64.19%). Regarding PGT-A cycles, the rate of blastocyst aneuploidy was significantly higher in the GnRH-ant protocol group than the GnRH-a long protocol group (39.69% vs. 52.27%). After stratification and multiple linear regression, the GnRH-ant regimen remained significantly associated with an increased risk of aneuploidy in early aborted tissues and blastocysts [OR (95% CI) 1.81 (1.21, 2.71), OR (95% CI) 1.65 (1.13, 2.42)]. Furthermore, the blastocyst aneuploidy rate in the GnRH-ant protocol group was significantly higher but only in young and normal ovarian responders [OR (95% CI) 5.07 (1.99, 12.92)].

CONCLUSION

Compared to the GnRH-a long protocol, the GnRH-ant protocol is associated with a higher aneuploidy rate in early aborted tissues and blastocysts. These results should be confirmed in a multicenter, randomized controlled trial.

Estradiol (E2) Reduction Adversely Affect the Embryo Quality and Clinical Outcomes of In Vitro Fertilization and Embryo transfer (IVF-ET)

Objective

The purpose of this study was to explore the influence of decreased serum estradiol (E₂) levels during controlled ovarian hyperstimulation (COH) on in vitro fertilization and embryo transfer (IVF).

Methods

The clinical data of 300 IVF-ET cycles with patients were analyzed retrospectively. According to the presence of falling E₂ level during the COH, we divided all subjects into two groups: the E₂ levels fall group (n = 120, group A) and the control group (n = 180, group B). In group A, there were 57 patients with falling E₂ with drug dosage reduction. The other 63 patients experienced the decreased E₂ level spontaneously. The clinical and laboratory variables in the groups were compared. Receiver operator characteristic (ROC) curve analyses were carried out in order to evaluate the predict value of E₂ level on the day of human chorionic gonadotropin (hCG) administration on IVF outcomes.

Results

Duration and total dosage of gonadotropin (Gn) used were statistically more in group A than in group B (P < 0.001). The high-quality embryo rate was significantly lower in group A (P = 0.048). Women in group A had lower clinical pregnancy rate (P = 0.029), live birth rate (P < 0.001), ongoing pregnancy rate (P = 0.001), and higher early abortion rates (P = 0.008) than group B. Women with spontaneously falling E₂ group had a higher BMI index than those in the drug dosage reduction group (P = 0.001). More dosage and longer duration of Gn in spontaneously falling E₂ group than in the drug dosage reduction group (P < 0.01). There were no differences in clinical outcomes between the two types of E₂ decreased groups. Results from ROC showed an E₂ level <1987.5 pg/ml on the hCG day might predict early abortion in this study. The sensitivity was 58.4% and the specificity was 78.9%. In addition, an E₂ level >2020 pg/ml on the hCG day might be an index to predict live birth. The sensitivity was 57.0% and the specificity was 61.7%.

Conclusions

Reduction of E₂ during COH might adversely affect the clinical pregnancy, early abortion, and ongoing pregnancy of IVF-ET.

Comparison of day 5 blastocyst with day 6 blastocyst: Evidence from NGS-based PGT-A results

PURPOSE

Aneuploidy is one genetic factor leading to the failure of embryo implantation. This study aimed to investigate the relationship between the day of embryo blastulation and the ploidy status of embryo, to aid in selecting embryos with the most likelihood of of being euploid in a noninvasive way.

METHODS

This retrospective study recruited women undergoing preimplantation genetic testing (PGT) for aneuploidy (PGT-A) with trophectoderm biopsy from January 2019 to December 2020. The ploidy status of embryos was determined by next-generation sequencing (NGS).

RESULTS

Altogether, 2531 blastocysts from 839 PGT-A cycles were evaluated. The euploid rate of day 5 blastocysts was significantly higher than that of day 6 blastocysts, either from the same ovarian stimulation (OS) cycles (49.9% vs 35.7%, P < 0.001) or from different OS cycles (48.2% vs 27.8%, P < 0.001). This effect of increasing time to embryo blastulation significantly reducing the prevalence of euploidy was not seen in women at age 38 or older. However, after single euploid embryo transfer, the clinical outcomes of day 5 blastocysts were comparable to those of day 6 blastocysts.

CONCLUSIONS

In non-PGT cycles, our data support the selection of day 5 blastocysts for transfer over day 6 blastocysts. Further, women with poor ovarian reserve incline to obtain only day 6 blastocysts, and PGT-A is valuable for identifying the ploidy status of embryos, especially for those with advanced age. However, the stage of blastocysts will not affect the clinical outcome after transfer when they are identified as euploid.

Single-cell RNA-seq analysis and cell-cluster deconvolution of the human preovulatory follicular fluid cells provide insights into the pathophysiology of ovarian hyporesponse

Reduction in responsiveness to gonadotropins or hyporesponsiveness may lead to the failure of in vitro fertilization (IVF), due to a low number of retrieved oocytes. The ovarian sensitivity index (OSI) is used to reflect the ovarian responsiveness to gonadotropin stimulation before IVF. Although introduced to clinical practice already years ago, its usefulness to predict clinical outcomes requires further research. Nevertheless, pathophysiological mechanisms of ovarian hyporesponse, along with advanced maternal age and in younger women, have not been fully elucidated. Follicles consist of multiple cell types responsible for a repertoire of biological processes including responding to pituitary gonadotropins necessary for follicle growth and oocyte maturation as well as ovulation. Encouraging evidence suggests that hyporesponse could be influenced by many contributing factors, therefore, investigating the variability of ovarian follicular cell types and their gene expression in hyporesponders is highly informative for increasing their prognosis for IVF live birth. Due to advancements in single-cell analysis technologies, the role of somatic cell populations in the development of infertility of ovarian etiology can be clarified. Here, somatic cells were collected from the fluid of preovulatory ovarian follicles of patients undergoing IVF, and RNA-seq was performed to study the associations between OSI and gene expression. We identified 12 molecular pathways differentially regulated between hypo- and normoresponder patient groups (FDR<0.05) from which extracellular matrix organization, post-translational protein phosphorylation, and regulation of Insulin-like Growth Factor (IGF) transport and uptake by IGF Binding Proteins were regulated age-independently. We then generated single-cell RNA-seq data from matching follicles revealing 14 distinct cell clusters. Using cell cluster-specific deconvolution from the bulk RNA-seq data of 18 IVF patients we integrated the datasets as a novel approach and discovered that the abundance of three cell clusters significantly varied between hypo- and normoresponder groups suggesting their role in contributing to the deviations from normal ovarian response to gonadotropin stimulation. Our work uncovers new information regarding the differences in the follicular gene expression between hypo- and normoresponders. In addition, the current study fills the gap in understanding the inter-patient variability of cell types in human preovulatory follicles, as revealed by single-cell analysis of follicular fluid cells.

High initial FSH dosage reduces the number of available cleavage-stage embryos in a GnRH-antagonist protocol: Real-world data of 8,772 IVF cycles from China

To evaluate the relationship between the initial follicle stimulating hormone (FSH) dose and the number of available cleavage-stage embryos in in vitro fertilization (IVF) cycles.We included 8772 fresh IVF cycles using a GnRH antagonist protocol at the Genetic and Reproductive Institution of Chongqing, P. R. China, from January 2016 to June 2021.Univariate linear regression was used to evaluate the associations between the initial FSH dosage (≤ 150, 187.5-200, 225, 250, or 300 IU) with the number of available cleavage-stage embryos on day 3. A two-factor linear regression model was applied to calculate the threshold effect of the initial FSH dosage on the number of available cleavage-stage embryos based on a smoothing plot. The initial FSH dose was negatively correlated with the number of available cleavage-stage embryos, independent of female age, body mass index, infertility factors, duration of infertility, anti-Müllerian hormone and basal FSH levels, antral follicle count and the proportions of patients with poor ovarian response or polycystic ovarian syndrome. Using a two-factor linear regression model, we calculated the inflection point to be 200 IU of FSH. The relationship between the initial FSH dose and the number of available cleavage-stage embryos was nonlinear. The initial FSH dose was negatively associated with the number of available cleavage-stage embryos when the initial FSH dose was > 200 IU. Therefore, clinicians should try to avoid unnecessarily increasing the initial FSH dose.

The putative roles of FSH and AMH in the regulation of oocyte developmental competence: from fertility prognosis to mechanisms underlying age-related subfertility

BACKGROUND

Fertility loss during female ageing is associated with increasing basal FSH and decreasing anti-Müllerian hormone (AMH) concentrations, together with compromised oocyte quality, presumably due to increased oxidative stress (OS) and DNA damage, as well as reduced metabolic and meiotic competences. Basal FSH and AMH circulatory concentrations have been broadly utilized as IVF success predictors, regardless of fluctuations in prognostic accuracy; basal FSH and AMH perform better in pre-advanced maternal age (AMA: >35 years) and AMA patients, respectively. The relationships between FSH and AMH intrafollicular levels and IVF outcomes suggest, nevertheless, that both hormones regulate oocyte competence, supporting the hypothesis that changes in FSH/AMH levels cause, at least in part, oocyte quality degradation during ageing. To understand the reasons behind the fluctuations in FSH and AMH prognostic accuracies and to clarify their participation in mechanisms determining oocyte competence and age-related subfertility, a deeper knowledge of the regulation of FSH and AMH intrafollicular signalling during the female reproductive lifespan, and of their effects on the cumulus-oocyte complex, is required.

OBJECTIVE AND RATIONALE

An extensive body of information on the regulation of FSH and AMH intrafollicular availability and signalling, as well as on the control of folliculogenesis and oocyte metabolism, has been accumulated. However, these datasets have been explored within the relatively narrow boundaries of their specific subjects. Given the aforementioned gaps in knowledge and their clinical relevance, herein we integrate clinical and basic data, within a wide biological perspective, aiming to shed light on (i) the reasons for the variability in the accuracy of serum FSH and AMH as fertility markers, and on (ii) the potential roles of these hormones in mechanisms regulating oocyte quality, particularly those associated with ageing.

SEARCH METHODS

The PubMed database encompassing the period between 1960 and 2021 was searched. Principal search terms were FSH, FSH receptor, AMH, oocyte, maternal age, cumulus, transzonal projections (TZPs), actin, OS, redox, reactive oxygen species, mitochondria, DNA damage, DNA repair, aneuploidy, spindle, meiosis, gene expression, transcription, translation, oocyte secreted factors (OSFs), cAMP, cyclic guanosine monophosphate, natriuretic peptide C, growth differentiation factor 9, bone morphogenetic protein 15 and fibroblast growth factor.

OUTCOMES

Our analysis suggests that variations in the accuracy of fertility prognosis reflect a modest association between circulatory AMH levels and oocyte quality as well as increasing basal FSH inter-cycle variability with age. In addition, the basic and clinical data articulated herein support the hypothesis that increased intrafollicular FSH levels, as maternal age advances, may override the physiological protective influences of AMH and OSFs against excessive FSH signalling in cumulus cells. This would result in the disruption of oocyte homeostasis via reduced TZP-mediated transfer of cumulus-derived molecules essential for meiotic competence, gene expression, redox activity and DNA repair.

WIDER IMPLICATIONS

In-depth data analysis, encompassing a wide biological perspective has revealed potential causative mechanisms of age-related subfertility triggered by alterations in FSH/AMH signalling during the female reproductive life. Insights from new mechanistic models arising from this analysis should contribute to advancing our comprehension of oocyte biology in humans and serve as a valuable reference for novel AMA subfertility treatments aimed at improving oocyte quality through the modulation of AMH/FSH action.

Cofilin regulates actin network homeostasis and microvilli length in mouse oocytes

How multiple actin networks coexist in a common cytoplasm while competing for a shared pool of monomers is still an ongoing question. This is exemplified by meiotic maturation in the mouse oocyte, which relies on the dynamic remodeling of distinct cortical and cytoplasmic F-actin networks. Here, we show that the conserved actin-depolymerizing factor cofilin is activated in a switch-like manner upon meiosis resumption from prophase arrest. Interfering with cofilin activation during maturation resulted in widespread elongation of microvilli, while cytoplasmic F-actin was depleted, leading to defects in spindle migration and polar body extrusion. In contrast, cofilin inactivation in metaphase II-arrested oocytes resulted in a shutdown of F-actin dynamics, along with a dramatic overgrowth of the polarized actin cap. However, inhibition of the Arp2/3 complex to promote actin cap disassembly elicited ectopic microvilli outgrowth in the polarized cortex. These data establish cofilin as a key player in actin network homeostasis in oocytes and reveal that microvilli can act as a sink for monomers upon disassembly of a competing network.

A short length of gonadotropin hyperstimulation is sufficient to achieve an optimal IVF outcome in advance-aged women

OBJECTIVE

To analyze the duration of gonadotropin hyperstimulation's impacts on oocyte quality and clinical outcomes in aged in vitro fertilization (IVF) patients.

MATERIALS AND METHODS

This retrospective study was carried out using IVF records of the Chang Gung Memorial Hospital IVF center from January 2017 to December 2019. A total of 308 IVF cycles with patients aged 40-44 years were included. Clinical characteristics of patients who received a short controlled ovarian hyperstimulation (COH) (i.e., 6-7 days; s-COH group) or a long COH treatment (i.e., 9-10 days; l-COH group) were compared. In addition, analysis was conducted using data within two age subgroups: 40-42 years and 42-44 years subgroups.

RESULTS

The s-COH group received significantly lower total doses of gonadotropin and had smaller leading follicles at the time of ovulation trigger when compared to the l-COH group. The s-COH group also produced a significantly lower number of oocytes, mature metaphase II (MII) oocytes, and 2 PN zygotes compared to the l-COH group. However, there was no significant difference in the number of transferable and good-quality embryos between the two treatment groups. Likewise, the pregnancy rate and live birth rate were comparable in the s-COH and l-COH groups. Similar results were obtained when the analysis was limited to select age subgroups (i.e., 40-42 and 42-44 years subgroups).

CONCLUSION

While a long COH generates more oocytes per cycle, a 6-7 days COH treatment, which is at the lower end of the recommended window of stimulation, could achieve a pregnancy outcome comparable to that applied 9-10 days of COH in aged patients.

FSH dose is negatively correlated with number of oocytes retrieved: analysis of a data set with ~650,000 ART cycles that previously identified an inverse relationship between FSH dose and live birth rate

PURPOSE

To evaluate whether total FSH dose was negatively correlated with number of oocytes retrieved in a large data set where previously, a negative correlation between FSH dose and live birth rate was identified.

METHODS

Data from 650,637 fresh autologous in vitro fertilization (IVF) cycles reported to the Society for Assisted Reproductive Technology between 2004 and 2012 were included. Logistic regression analysis was performed to determine if the relationship between total FSH dose used during ART with number of oocytes retrieved was impacted by the patient's health prognosis, age, BMI, ovarian stimulation protocol, or infertility diagnosis.

RESULTS

The number of oocytes retrieved was negatively correlated with FSH dose (P < 0.0001). Regardless of patient prognosis, age, BMI, ovarian stimulation protocol, and infertility diagnosis, the highest number of oocytes retrieved was in the 1001-2000 IU FSH group, and was 36-51% lower in the > 5000 IU compared with the optimal, 1001-2000 IU, FSH groups. Overall, ~80% of patients received FSH doses outside of the optimal FSH dose. Moreover, 61% of good prognosis patients (excludes individuals likely prescribed higher FSH doses) received doses exceeding the optimal dose range.

CONCLUSION

The inverse relationship between FSH dose and the number of oocytes retrieved independent of patient age or health implies that excessive FSH doses during ART may be detrimental to oocyte retrieval.

Length of ovarian stimulation does not impact live birth rate in fresh donor oocyte cycles: a SART CORS study

PURPOSE

To evaluate the effect of controlled ovarian hyperstimulation length and total gonadotropin (GN) dose on recipient live birth rate (LBR) in fresh donor oocyte cycles.

METHODS

Data was obtained from SART CORS on all fresh donor oocyte GnRH antagonist cycles (n = 1049) between 2014 and 2015 which resulted in a single embryo transferred. Donor and recipient demographic information and cycle characteristics were extracted. Binomial regression was used to estimate LBR with respect to days of stimulation (DOS) and total GN dose. Multivariate analysis was performed to evaluate these relationships after controlling for confounders.

RESULTS

Overall LBR in fresh donor oocyte cycles was 57%. Average stimulation length was 14.3 ± 4.9 days, and total GN dose was 2464 ± 1062 IU. On univariate analysis, neither days of stimulation (p = 0.5) nor total GN dose (p = 0.57) was independently correlated with LBR. However, in prolonged stimulations (> 15 days) with high total GN dose (> 3000 IU), as both the cycle length and total GN dose increased, LBR significantly decreased from 63.81 to 48.15% (p = 0.02) and from 67.61 to 48.15% (p = 0.01), respectively. Multivariate analysis showed no significant effect of either DOS or total GN dose on LBR.

CONCLUSIONS

LBR is significantly decreased in fresh donor oocyte cycles when cycles are prolonged with high total GN dose. However, after controlling for confounders neither DOS nor total GN dose significantly affects LBR.

Differential impact of controlled ovarian hyperstimulation on live birth rate in fresh versus frozen embryo transfer cycles: a Society for Assisted Reproductive Technology Clinic Outcome System study

OBJECTIVE

To study the impact of both controlled ovarian hyperstimulation (COH) length and total gonadotropin (GN) dose individually and in concert on live birth rates (LBR) in both fresh and freeze-all in vitro fertilization embryo transfer (IVF-ET) cycles.

DESIGN

Historical cohort study.

SETTING

Not applicable.

PATIENT(S)

The U.S. national database from the Society of Assisted Reproductive Technology Clinic Outcome Reporting System from 2014 to 2015 was used to identify patients undergoing autologous GN stimulation IVF cycles with the use of GnRH antagonist-based suppression protocols where a single embryo transfer was performed as part of a fresh IVF-ET cycle (fresh, n = 14,866) or the first frozen embryo transfer after a freeze-all cycle (frozen, n = 2,964), and not including preimplantation genetic testing cycles. The patients' demographic and cycle characteristics, duration of COH, total GN dose, and pregnancy outcomes were extracted. Binomial regression models estimated trend and relative risk of live birth with respect to days of stimulation and total GN dose singularly, and after adjustment for a priori confounders including age, parity, body mass index, diagnosis, and maximum follicle-stimulating hormone in both fresh and frozen embryo transfer cycles. Both days of stimulation and total GN dose were then added to the multivariate model to show whether they were independently associated with LBR.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Live birth rate.

RESULTS

In both fresh and frozen cycles, length of COH was significantly associated with total GN dose. On univariate analysis, LBR decreased significantly with increasing length of stimulation and increasing total GN dose in both fresh and frozen cycles. On multivariable analysis including both days of stimulation and total GN dose, days of stimulation was no longer significantly correlated with LBR, whereas total GN dose remained significantly correlated with LBR in fresh cycles only. When total GN doses ranging from <2,000 IU through 5,000 IU to >5,000 IU were compared, a significant improvement in live birth rate was noted with lower total GN doses. Specifically, GN doses <2,000 IU had a 27% higher rate of live birth compared with GN dose >5,000 IU. For GN dose groups up to 4,000 IU, the estimated effect on LBR was similar. There was a marginal improvement (13%) in LBR with GN doses of 4,000 IU to 5,000 IU compared with >5,000 IU. When the multivariate model was applied to the frozen cycles, neither total GN dose nor days of stimulation was significantly associated with LBR.

CONCLUSIONS

High total GN dose but not prolonged COH is associated with decreasing LBRs in fresh cycles, whereas neither factor significantly affects LBR in frozen cycles. Consideration should be given to minimizing the total GN dose when possible in fresh autologous cycles, either by decreasing the daily dose or by limiting the length of stimulation to improve LBRs. In freeze-all cycles, the use of higher GN doses does not seem to adversely affect the LBR of the first frozen embryo transfer. High total GN dose likely exerts a negative impact on the endometrium and/or oocyte/embryo unrelated to the length of stimulation. The differential effect of total GN dose on LBR in fresh and frozen cycles may imply a greater impact exerted on the endometrium rather than the oocyte.

Follicle-stimulating hormone administration affects amino acid metabolism in mammalian oocytes†

Culture media used in assisted reproduction are commonly supplemented with gonadotropin hormones to support the nuclear and cytoplasmic maturation of in vitro matured oocytes. However, the effect of gonadotropins on protein synthesis in oocytes is yet to be fully understood. As published data have previously documented a positive in vitro effect of follicle-stimulating hormone (FSH) on cytoplasmic maturation, we exposed mouse denuded oocytes to FSH in order to evaluate the changes in global protein synthesis. We found that dose-dependent administration of FSH resulted in a decrease of methionine incorporation into de novo synthesized proteins in denuded mouse oocytes and oocytes cultured in cumulus-oocyte complexes. Similarly, FSH influenced methionine incorporation in additional mammalian species including human. Furthermore, we showed the expression of FSH-receptor protein in oocytes. We found that major translational regulators were not affected by FSH treatment; however, the amino acid uptake became impaired. We propose that the effect of FSH treatment on amino acid uptake is influenced by FSH receptor with the effect on oocyte metabolism and physiology.

No effect of ovarian stimulation and oocyte yield on euploidy and live birth rates: an analysis of 12 298 trophectoderm biopsies

STUDY QUESTION

Does ovarian stimulation affect embryo euploidy rates or live birth rates (LBRs) after transfer of euploid embryos?

SUMMARY ANSWER

Euploidy rates and LBRs after transfer of euploid embryos are not significantly influenced by gonadotropin dosage, duration of ovarian stimulation, estradiol level, follicle size at ovulation trigger or number of oocytes retrieved, regardless of a woman’s age.

WHAT IS KNOWN ALREADY

Aneuploidy rates increase steadily with age, reaching &gt;80% in women &gt;42 years old. The goal of ovarian stimulation is to overcome this high aneuploidy rate through the recruitment of several follicles, which increases the likelihood of obtaining a euploid embryo that results in a healthy conceptus. However, several studies have suggested that a high response to stimulation might be embryotoxic and/or increase aneuploidy rates by enhancing abnormal segregation of chromosomes during meiosis. Furthermore, a recent study demonstrated a remarkable difference in euploidy rates, ranging from 39.5 to 82.5%, among young oocyte donors in 42 fertility centres, potentially suggesting an iatrogenic etiology resulting from different stimulation methods.

STUDY DESIGN, SIZE, DURATION

This is a retrospective cohort study that included 2230 in vitro fertilisation (IVF) with preimplantation genetic testing for aneuploidy (PGT-A) cycles and 930 frozen-thawed single euploid embryo transfer (FET) cycles, performed in our centre between 2013 and 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 12 298 embryos were analysed for ploidy status. Women were divided into five age groups (&lt;35, 35–37, 38–40, 41–42 and &gt;42 years old). Outcomes were compared between different durations of stimulation (&lt;10, 10–12 and ≥13 days), total gonadotropin dosages (&lt;4000, 4000–6000 and &gt;6000 IU), numbers of oocytes retrieved (&lt;10, 10–19 and ≥20 oocytes), peak estradiol levels (&lt;2000, 2000–3000 and &gt;3000 pg/mL), and sizes of the largest follicle on the day of trigger (&lt;20 and ≥20 mm).

MAIN RESULTS AND THE ROLE OF CHANCE

Within the same age group, both euploidy rates and LBRs were comparable between cycles regardless of their differences in total gonadotropin dosage, duration of stimulation, number of oocytes harvested, size of the largest follicles or peak estradiol levels. In the youngest group, (&lt;35 years, n = 3469 embryos), euploidy rates were comparable between cycles with various total gonadotropin dosages (55.6% for &lt;4000 IU, 52.9% for 4000–6000 IU and 62.3% for &gt;6000 IU; P = 0.3), durations of stimulation (54.4% for &lt;10 days, 55.2% for 10–12 days and 60.9% for &gt;12 days; P = 0.2), number of oocytes harvested (59.4% for &lt;10 oocytes, 55.2% for 10–19 oocytes and 53.4% for ≥20 oocytes; P = 0.2), peak estradiol levels (55.7% for E2 &lt; 2000 pg/mL, 55.4% for E2 2000–3000 pg/mL and 54.8% for E2 &gt; 3000 pg/mL; P = 0.9) and sizes of the largest follicle (55.6% for follicles &lt;20 mm and 55.1% for follicles ≥20 mm; P = 0.8). Similarly, in the oldest group (&gt;42 years, n = 1157 embryos), euploidy rates ranged from 8.7% for gonadotropins &lt;4000 IU to 5.1% for gonadotropins &gt;6000 IU (P = 0.3), from 10.8% for &lt;10 days of stimulation to 8.5% for &gt;12 days of stimulation (P = 0.3), from 7.3% for &lt;10 oocytes to 7.4% for ≥20 oocytes (P = 0.4), from 8.8% for E2 &lt; 2000 pg/mL to 7.5% for E2 &gt; 3000 pg/mL (P = 0.8) and from 8.2% for the largest follicle &lt;20 mm to 8.9% for ≥20 mm (P = 0.7). LBRs after single FET were also comparable between these groups.

LIMITATIONS, REASONS FOR CAUTION

Although this large study (2230 IVF/PGT-A cycles, 12 298 embryos and 930 single FET cycles) demonstrates the safety of ovarian stimulation in terms of aneuploidy and implantation potential of euploid embryos, a multi-centre study may help to prove the generalisability of our single-centre data.

WIDER IMPLICATIONS OF THE FINDINGS

These findings reassure providers and patients that gonadotropin dosage, duration of ovarian stimulation, estradiol level, follicle size at ovulation trigger and number of oocytes retrieved, within certain ranges, do not appear to significantly influence euploidy rates or LBRs, regardless of the woman’s age.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received and there are no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A

Listening to mother: Long-term maternal effects in mammalian development

The oocyte is a complex cell that executes many crucial and unique functions at the start of each life. These functions are fulfilled by a unique collection of macromolecules and other factors, all of which collectively support meiosis, oocyte activation, and embryo development. This review focuses on the effects of oocyte components on developmental processes that occur after the initial stages of embryogenesis. These include long-term effects on genome function, metabolism, lineage allocation, postnatal progeny health, and even subsequent generations. Factors that regulate chromatin structure, genome programming, and mitochondrial function are elements that contribute to these oocyte functions.

Effect of FSH on E2/GPR30-mediated mouse oocyte maturation in vitro

Mammalian oocyte restores meiosis can be stimulated by follicle-stimulating hormone (FSH) under normal physiological conditions. G-protein coupled receptor 30 (GPR30), an non-classical estrogen membrane receptor, has been widely reported in teleost oocyte maturation. However, it remains unknown whether GPR30 involves the role of FSH in mammalian cumulus expansion and oocyte maturation. Here, we used mouse cumulus-oocyte complexes (COCs) as a model to investigate how FSH affects the in vitro maturation of mouse oocytes mediated by 17β-estradiol (E₂)/GPR30signaling. Our study reveals that FSH starts regulating mouse cumulus expansion precisely at 8h in in vitro culture. ELISA measurement of E₂ levels in culture medium revealed that FSH activated aromatase to promote E₂ production in vitro in cultured mouse COCs. Moreover, the results of real-time quantitative PCR indicated that FSH-induced in vitro maturation of mouse oocytes was regulated by the estrogen-signaling pathway mediated by GPR30; FSH treatment markedly increased the mRNA expression of HAS2, PTGS2, and GREM1 in COCs. Exploration of the underlying mechanism suggested that E₂ produced by mouse COCs regulated the phosphorylation level of extracellular signal-regulated kinase 1/2 (ERK1/2) through GPR30 and thereby promoted mouse cumulus-cell expansion and oocyte maturation. In conclusion, our study reveals that FSH induced estrogen production in mouse COCs through aromatase, and that aromatase/GPR30/ERK1/2 signaling is involved in FSH-induced cumulus expansion.

Fully human glyco-optimized recombinant FSH (follitropin epsilon) - a randomized, comparator-controlled phase II clinical trial

RESEARCH QUESTION

The study aimed to determine the standard treatment dose of follitropin epsilon for ovarian stimulation in the context of IVF treatment.

DESIGN

A total of 247 women aged 18-37 years were treated with either 52.5, 75, 112.5 or 150 IU follitropin epsilon daily, or 150 IU every other day, or 150 IU follitropin alfa daily in a long gonadotrophin-releasing hormone agonist protocol. The study was performed as a randomized, assessor-blinded, comparator-controlled, six-armed phase II trial in eight fertility clinics in two European countries.

RESULTS

The primary results were as follow. First, none of the doses of follitropin epsilon showed superiority for the main outcome measure, i.e. number of follicles ≥12 mm in size. Follitropin epsilon 75 IU produced results most similar to those of follitropin alfa 150 IU. In terms of secondary results, stronger effects of follitropin epsilon 112.5 IU compared with follitropin alfa 150 IU were seen for secondary outcome measures such as hormone concentrations (oestradiol, inhibin B and progesterone) and oocyte number.

CONCLUSIONS

Follitropin epsilon 75 IU daily results in a similar ovarian response to a standard dose of 150 IU follitropin alfa. This dose could be tested in a phase III trial.

Amino acid supplementation of a simple inorganic salt solution supports efficient in vitro maturation (IVM) of bovine oocytes

Defining oocyte in vitro maturation (IVM) conditions allows for improved reproducibility and efficiency of bovine embryo production. IVM conditions for bovine oocytes have been extensively studied, but beneficial effects of individual supplements remain controversial. This study compared methods of cumulus oocyte complex (COC) isolation, and culture medium requirements, for IVM in order to define optimal conditions. Antral follicles in ovaries were sliced or aspirated to isolate COCs. Brilliant cresyl blue staining of COCs was used to determine the most effective collection technique and the effect of hormones and groups of amino acids in the culture medium was investigated. Our results showed COCs isolated through aspiration had greater meiotic competency to reach MII. Oocyte maturation was achieved with the addition of 1 µg/mL FSH, while estrogen and human chorionic gonadotrophin did not increase the number of MII oocytes. We also provide novel data, that supplementation of a simple inorganic salt solution with L-proline, L-glutamine and essential amino acids in combination, but not individually, resulted in nuclear maturation comparable to TCM199, a more complex medium containing all 20 common amino acids, vitamins, inorganic salts and FBS. Replacement of FBS with BSA in this simplified medium creates a defined medium which provides conditions for IVM that enable reproducible maturation rates.

Clinical pregnancy (CP) and live birth (LB) increase significantly with each additional fertilized oocyte up to nine, and CP and LB decline after that: an analysis of 15,803 first fresh in vitro fertilization cycles from the Society for Assisted Reproductive Technology registry

OBJECTIVE

To study the association between the total number of fertilized oocytes available and pregnancy outcomes in first fresh IVF cycles with a single blastocyst transfer.

DESIGN

Retrospective cohort study.

SETTING

Not applicable.

PATIENT(S)

A total of 15,803 patients from SART reporting fertility clinics.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Primary outcomes were clinical pregnancy (CP), live birth (LB), and miscarriage rates. Logistic regression was used to investigate the association between the number of fertilized eggs and each outcome.

RESULT(S)

The median number of total oocytes was 15, and the median number of fertilized oocytes was nine. The odds of a clinical pregnancy were 8% higher for each additional fertilized oocyte up to nine (odds ratio [OR] 1.08; 95% confidence interval [CI] 1.07-1.10) and declined by 9% for every additional fertilized oocyte after nine (OR 0.91; 95% CI 0.89-0.94). Similarly, the odds of an LB was 8% higher for every additional fertilized oocyte up to none (OR 1.08; 95% CI 1.06-1.10) and declined by 8% for every additional fertilized oocyte over nine (OR 0.92; 95% CI 0.90-0.94).

CONCLUSION(S)

Odds of pregnancy outcomes (CP, LB) increase significantly with every additional fertilized oocyte up to nine, and CP and LB decline after that in first fresh autologous cycles with a single blastocyst transfer.

Comparison of antagonist mild and long agonist protocols in terms of follicular fluid total antioxidant capacity

OBJECTIVE

A high dose of prolonged gonadotropins can yield higher numbers of oocytes and embryos. The high dose or prolonged regimens can be associated with ovarian hyperstimulation syndrome (OHSS), multiple gestations, emotional stress, economical burden and treatment dropout. In mild stimulation lower doses and shorter duration times of gonadotropin are used in contrast to the conventional long stimulation protocol in IVF. It has been proposed that supraphysiologic levels of hormones may adversely affect endometrium and oocyte/embryo. Also it has been proposed that oxidative stress (OS) may alter ovarian hormone dynamics and could be further affected by additional exogenous hormonal stimulation. Therefore our aim was to compare follicular fluid total antioxidant capacity (TAC) in antagonist mild and long agonist stimulations.

MATERIALS AND METHODS

Forty patients received antagonist mild stimulation, starting on the 5th day of their cycle and forty patients received long agonist treatment. Seventy-five patients undergoing their first IVF cycle were included in the final analysis. Follicular fluid (FF) samples were analyzed for estradiol (E2), antimullerian hormone (AMH) and TAC.

RESULTS

FF-Total antioxidant capacity (TAC) levels were higher in the long agonist group as opposed to the antagonist group [1.07 ± 0.04 mmol Trolox equivalent/L vs 1 ± 0.13 mmol Trolox equivalent/L] (Fig. 1). Pregnancy rates were not significantly different between the two treatments. The FF-TAC levels were not different among infertility etiologies (Fig. 3). FF-TAC levels did not have a direct correlation with pregnancy but a positive correlation with the total gonadotropin dose was observed.

CONCLUSION

Patients with good ovarian reserves and under the age of 35 effectively responded to mild stimulation treatment. Using lower amounts of gonadotropin, yielded less FF-TAC levels in patients who underwent antagonist mild protocol. In patients under the age of 35, antagonist mild stimulation is a patient friendly and effective procedure when undergoing their first IVF cycle.

In vitro maturation affects chromosome segregation, spindle morphology and acetylation of lysine 16 on histone H4 in horse oocytes

Implantation failure and genetic developmental disabilities in mammals are caused by errors in chromosome segregation originating mainly in the oocyte during meiosis I. Some conditions, like maternal ageing or in vitro maturation (IVM), increase the incidence of oocyte aneuploidy. Here oocytes from adult mares were used to investigate oocyte maturation in a monovulatory species. Experiments were conducted to compare: (1) the incidence of aneuploidy, (2) the morphology of the spindle, (3) the acetylation of lysine 16 on histone H4 (H4K16) and (4) the relative amount of histone acetyltransferase 1 (HAT1), K(lysine) acetyltransferase 8 (KAT8, also known as MYST1), histone deacetylase 1 (HDAC1) and NAD-dependent protein deacetylase sirtuin 1 (SIRT1) mRNA in metaphase II stage oocytes that were in vitro matured or collected from peri-ovulatory follicles. The frequency of aneuploidy and anomalies in spindle morphology was increased following IVM, along with a decrease in H4K16 acetylation that was in agreement with our previous observations. However, differences in the amount of the transcripts investigated were not detected. These results suggest that the degradation of transcripts encoding for histone deacetylases and acetyltransferases is not involved in the changes of H4K16 acetylation observed following IVM, while translational or post-translational mechanisms might have a role. Our study also suggests that epigenetic instabilities introduced by IVM may affect the oocyte and embryo genetic stability.

Impact of Equine and Bovine Oocyte Maturation in Follicular Fluid From Young and Old Mares on Embryo Production in Vitro

Equine follicular fluid (FF) provides autocrine and paracrine factors from theca, granulosa, and cumulus cells, both reflecting and impacting oocyte and follicle maturation. We hypothesized that maturation of oocytes in FF from old versus young mares has a deleterious effect on oocyte maturation and their subsequent developmental potential. Follicular fluid was collected from the large, dominant follicle from young mares (4-13 years) or old mares (21-26 years) and classified as: (1) Noninduced follicular fluid (NFF), FF from noninduced follicle 33 ± 3 mm, or (2) Induced follicular fluid (IFF), FF collected ∼24 hours after administration of ovulation-inducing drugs when a follicle 33 ± 3 mm was observed. In experiment 1, immature equine oocytes were collected, matured in vitro for 30 ± 2 hours in 100% IFF, collected from young or old mares, with the addition of follicle stimulating hormone (5 mU/mL), then fertilized by intracytoplasmic sperm injection. In experiment 2, immature bovine oocytes were collected, matured in 100% IFF or NFF, collected from young mares or old mares, then fertilized via in vitro fertilization. In experiment 1, more blastocysts tended (P = .08) to be produced from equine oocytes that were matured in old versus young mare FF. In experiment 2, when IFF and NFF groups were combined, cleavage rates were higher (P = .001) when bovine oocytes were matured in FF from young than old mares. In contrast to our hypothesis, we observed no conclusive evidence that FF from old mares has a deleterious impact on oocytes and their early developmental potential.

Effect of Body Weight on Metabolic Hormones and Fatty Acid Metabolism in Follicular Fluid of Women Undergoing In Vitro Fertilization: A Pilot Study

INTRODUCTION

Obesity is an epidemic affecting more than one-third of adults in the United States. Obese women experience decreased fertility, explained in part by oocyte quality. Since follicular fluid (FF) provides an important microenvironment for oocyte growth, we sought to evaluate the effect of increased body weight on FF levels of 11 metabolic hormones and fatty acid metabolism.

METHODS

The FF was collected from 25 women (10 normal weight, 10 overweight, and 5 obese) with diminished ovarian reserve undergoing in vitro fertilization (IVF) following a minimal stimulation protocol. Hormone levels were determined by multiplex immunoassay using the MAGPIX (Luminex, Austin, Texas) instrument. Fatty acid metabolites were determined using gas and ultra-high pressure liquid chromatography coupled with mass spectrometry.

RESULTS

Levels of hormones related to glucose and energy homeostasis and regulation of fat stores (insulin, glucagon, glucagon-like peptide-1, C-peptide, and leptin) were increased significantly in FF from obese women compared to FF from nonobese(normal weight and overweight) women. Interestingly, FF levels of branched-chain amino acids (BCAA) isoleucine, leucine, and valine as well as uric acid, isocaproic acid, butanoic acid, tyrosine, threonine, glycine, and methionine correlated positively with body mass index.

CONCLUSION

This pilot study demonstrates significant alterations in the FF milieu of obese women undergoing IVF, which may contribute to the decreased fecundity of obese women. Although the impact of this environment on oocyte and embryo development is not fully realized, these changes may also lead to imprinting at the genomic level and long-term sequelae on offspring.

Low dose clomiphene citrate as a mild stimulation protocol in women with unsuspected poor in vitro fertilization result can generate more oocytes with optimal cumulative pregnancy rate

BACKGROUND

The use of long protocol during controlled ovarian stimulation for assisted reproduction attracts high dosage of gonadotropins. High dose of gonadotropins can be detrimental to oocyte development, which affects its quality and compromises the treatment outcome. Mild stimulation protocols that attract low dose gonadotropins could be useful alternative regimen to address such problems. This study evaluated the efficacy of low dose clomiphene citrate based protocol plus low dose gonadotropins on predicted normal responder patients who had unsuspected poor in vitro fertilization (IVF) result, following an initial stimulation with long gonadotropin-releasing hormone (GnRH) agonist protocol.

METHODS

This a retrospective study of 65 infertile women who underwent 130 cycles in our center from January 2011 to December 2014. The initial IVF cycle (Group 1) was treated with long GnRH-a protocol plus a high dose of gonadotropins (≥150 IU/d), while second IVF cycle (Group 2) had low dose clomiphene citrate based protocol plus low dose gonadotropins (75-112.5 IU/d).

RESULTS

The rate of cumulative pregnancy/started cycle (9.2% [6/65] vs. 51% [33/65]; P < 0001) was significantly better in CC protocol than the long GnRH agonist protocol. The number of oocytes retrieved was also higher in CC protocol compared to the long protocol (7.26 ± 1.95 vs. 5.98 ± 1.31; P = 0.03). There was a lower number of patients without embryos (12.31% vs. 33.85%; p < 0.0001) in CC protocol than long protocol.

CONCLUSIONS

This study showed a better cumulative pregnancy rate in the low dose CC based protocol. There was a higher number of oocytes retrieved after using a lower total dose of recombinant FSH in CC protocol. Thus, clomiphene treatment plus low dose rFSH can be an alternative option for such patients in second cycle stimulation instead of repeating long protocol regimen. Randomized controlled studies with larger number of patients will be needed for more accurate evidence.

Reproductive failure in mice expressing transgenic follicle-stimulating hormone is not caused by loss of oocyte quality

Human female reproductive aging features declining ovarian follicle reserve and oocyte quality, and rising levels of circulating follicle-stimulating hormone (FSH). We determined the effects of elevated FSH on oocyte-embryo development in mature mice exhibiting premature infertility caused by progressively rising transgenic human FSH (TgFSH) levels. Oocyte-embryo developmental competence and quality were examined using oocyte maturation and aneuploidy rates, biomarkers of oocyte quality, and reciprocal embryo transfers assessed for implantation and pregnancy. In vitro maturation suggested that TgFSH exposure only hindered oocyte developmental competence in old females, as significantly more oocytes from ≥12-month-old TgFSH females remained at germinal vesicle stage compared with age-matched control oocytes. Aneuploidy rates were equivalent in oocytes from aging TgFSH compared with wildtype females. Cumulus cell expression levels of candidate biomarker Inhba, Egfr, and Rgs2 transcripts were elevated in associated aneuploid vs euploid oocytes from both TgFSH and wildtype females. In vivo, embryos transferred from subfertile 6-month-old TgFSH females to wildtype recipients yielded normal implantation rates and more pups born compared with controls. Transfer of wildtype embryos rescued the fertility of 6-month-old TgFSH-recipient females, although pup birth weight was reduced in TgFSH vs wildtype recipients. Our current findings show that elevated FSH had minimal disruption of either embryo developmental capacity or uterine function when examined in isolation, and the subfertility of TgFSH female mice was not caused by altered oocyte aneuploidy or quality.

Individualised gonadotropin dose selection using markers of ovarian reserve for women undergoing in vitro fertilisation plus intracytoplasmic sperm injection (IVF/ICSI)

BACKGROUND

During a cycle of in vitro fertilisation plus intracytoplasmic sperm injection (IVF/ICSI), women receive daily doses of gonadotropin follicle-stimulating hormone (FSH) to induce multifollicular development in the ovaries. Generally, the dose of FSH is associated with the number of eggs retrieved. A normal response to stimulation is often considered desirable, for example the retrieval of 5 to 15 oocytes. Both poor and hyper-response are associated with increased chance of cycle cancellation. Hyper-response is also associated with increased risk of ovarian hyperstimulation syndrome (OHSS). Clinicians often individualise the FSH dose using patient characteristics predictive of ovarian response such as age. More recently, clinicians have begun using ovarian reserve tests (ORTs) to predict ovarian response based on the measurement of various biomarkers, including basal FSH (bFSH), antral follicle count (AFC), and anti-Müllerian hormone (AMH). It is unclear whether individualising FSH dose based on these markers improves clinical outcomes.

OBJECTIVES

To assess the effects of individualised gonadotropin dose selection using markers of ovarian reserve in women undergoing IVF/ICSI.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Specialised Register, Cochrane Central Register of Studies Online, MEDLINE, Embase, CINAHL, LILACS, DARE, ISI Web of Knowledge, ClinicalTrials.gov, and the World Health Organisation International Trials Registry Platform search portal from inception to 27th July 2017. We checked the reference lists of relevant reviews and included studies.

SELECTION CRITERIA

We included trials that compared different doses of FSH in women with a defined ORT profile (i.e. predicted low, normal or high responders based on AMH, AFC, and/or bFSH) and trials that compared an individualised dosing strategy (based on at least one ORT measure) versus uniform dosing or a different individualised dosing algorithm.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. Primary outcomes were live birth/ongoing pregnancy and severe OHSS. Secondary outcomes included clinical pregnancy, moderate or severe OHSS, multiple pregnancy, oocyte yield, cycle cancellations, and total dose and duration of FSH administration.

MAIN RESULTS

We included 20 trials (N = 6088); however, we treated those trials with multiple comparisons as separate trials for the purpose of this review. Meta-analysis was limited due to clinical heterogeneity. Evidence quality ranged from very low to moderate. The main limitations were imprecision and risk of bias associated with lack of blinding.Direct dose comparisons in women according to predicted responseAll evidence was low or very low quality.Due to differences in dose comparisons, caution is warranted in interpreting the findings of five small trials assessing predicted low responders. The effect estimates were very imprecise, and increased FSH dosing may or may not have an impact on rates of live birth/ongoing pregnancy, OHSS, and clinical pregnancy.Similarly, in predicted normal responders (nine studies, three comparisons), higher doses may or may not impact the probability of live birth/ongoing pregnancy (e.g. 200 versus 100 international units: OR 0.88, 95% CI 0.57 to 1.36; N = 522; 2 studies; I2 = 0%) or clinical pregnancy. Results were imprecise, and a small benefit or harm remains possible. There were too few events for the outcome of OHSS to enable any inferences.In predicted high responders, lower doses may or may not have an impact on rates of live birth/ongoing pregnancy (OR 0.98, 95% CI 0.66 to 1.46; N = 521; 1 study), OHSS, and clinical pregnancy. However, lower doses probably reduce the likelihood of moderate or severe OHSS (Peto OR 2.31, 95% CI 0.80 to 6.67; N = 521; 1 study).ORT-algorithm studiesFour trials compared an ORT-based algorithm to a non-ORT control group. Rates of live birth/ongoing pregnancy and clinical pregnancy did not appear to differ by more than a few percentage points (respectively: OR 1.04, 95% CI 0.88 to 1.23; N = 2823, 4 studies; I2 = 34%; OR 0.96, 95% CI 0.82 to 1.13, 4 studies, I2=0%, moderate-quality evidence). However, ORT algorithms probably reduce the likelihood of moderate or severe OHSS (Peto OR 0.58, 95% CI 0.34 to 1.00; N = 2823; 4 studies; I2 = 0%, low quality evidence). There was insufficient evidence to determine whether the groups differed in rates of severe OHSS (Peto OR 0.54, 95% CI 0.14 to 1.99; N = 1494; 3 studies; I2 = 0%, low quality evidence). Our findings suggest that if the chance of live birth with a standard dose is 26%, the chance with ORT-based dosing would be between 24% and 30%. If the chance of moderate or severe OHSS with a standard dose is 2.5%, the chance with ORT-based dosing would be between 0.8% and 2.5%. These results should be treated cautiously due to heterogeneity in the study designs.

AUTHORS' CONCLUSIONS

We did not find that tailoring the FSH dose in any particular ORT population (low, normal, high ORT), influenced rates of live birth/ongoing pregnancy but we could not rule out differences, due to sample size limitations. In predicted high responders, lower doses of FSH seemed to reduce the overall incidence of moderate and severe OHSS. Moderate-quality evidence suggests that ORT-based individualisation produces similar live birth/ongoing pregnancy rates to a policy of giving all women 150 IU. However, in all cases the confidence intervals are consistent with an increase or decrease in the rate of around five percentage points with ORT-based dosing (e.g. from 25% to 20% or 30%). Although small, a difference of this magnitude could be important to many women. Further, ORT algorithms reduced the incidence of OHSS compared to standard dosing of 150 IU, probably by facilitating dose reductions in women with a predicted high response. However, the size of the effect is unclear. The included studies were heterogeneous in design, which limited the interpretation of pooled estimates, and many of the included studies had a serious risk of bias.Current evidence does not provide a clear justification for adjusting the standard dose of 150 IU in the case of poor or normal responders, especially as increased dose is generally associated with greater total FSH dose and therefore greater cost. However, a decreased dose in predicted high responders may reduce OHSS.

The effects of superovulation and reproductive aging on the epigenome of the oocyte and embryo

A societal preference of delaying maternal age at first childbirth has increased reliance on assisted reproductive technologies/therapies (ART) to conceive a child. Oocytes that have undergone physiologic aging (≥35 years for humans) are now commonly used for ART, yet evidence is building that suboptimal reproductive environments associated with aging negatively affect oocyte competence and embryo development-although the mechanisms underlying these relationship are not yet well understood. Epigenetic programming of the oocyte occurs during its growth within a follicle, so the ovarian stimulation protocols that administer exogenous hormones, as part of the first step for all ART procedures, may prevent the gamete from establishing an appropriate epigenetic state. Therefore, understanding how oocyte. Therefore, understanding how hormone stimulation and oocyte physiologic age independently and synergistically physiologic age independently and synergistically affect the epigenetic programming of these gametes, and how this may affect their developmental competence, are crucial to improved ART outcomes. Here, we review studies that measured the developmental outcomes affected by superovulation and aging, focusing on how the epigenome (i.e., global and imprinted DNA methylation, histone modifications, and epigenetic modifiers) of gametes and embryos acquired from females undergoing physiologic aging and exogenous ovarian stimulation is affected.

Increased odds of live birth in fresh in vitro fertilization cycles with shorter ovarian stimulation

OBJECTIVE

To investigate the impact of prolonged ovarian stimulation on pregnancy outcomes in IVF cycles with fresh day 3 ET.

DESIGN

Retrospective cohort study.

SETTING

University-affiliated center.

PATIENT(S)

All patients initiating their first IVF cycle with fresh day 3 ET. Prolonged ovarian stimulation was defined as a duration of more than two standard deviations (95th percentile) for the study cohort (i.e., >13 days).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Live birth rate was considered the primary outcome and was compared between patients undergoing ovarian stimulation for ≤13 days and >13 days. Odds ratios (OR) with 95% confidence intervals (CI) for all pregnancy outcomes after day 3 ET were calculated. The OR for live birth was adjusted using logistic regression.

RESULT(S)

A total of 6,410 and 339 patients underwent ovarian stimulation for ≤13 days and >13 days, respectively. There were no differences in the demographics or mean number of day 3 embryos transferred between the two groups. Ovarian stimulation ≤13 days was associated with increased odds of clinical pregnancy (OR 2.15, 95% CI 1.19-3.89) and live birth (OR 2.35, 95% CI 1.25-4.43). The increased odds for live birth in the ≤13-day group remained unchanged after logistic regression. Patients with clinical pregnancies in the >13-day group were younger (34.6 ± 4.91 years) compared with those who did not conceive (38.2 ± 4.72 years).

CONCLUSION(S)

Our findings suggest that ovarian stimulation ≤13 days is associated with increased odds of clinical pregnancy and live birth. In patients undergoing ovarian stimulation >13 days, younger age is associated with live birth.

Activin Decoy Receptor ActRIIB:Fc Lowers FSH and Therapeutically Restores Oocyte Yield, Prevents Oocyte Chromosome Misalignments and Spindle Aberrations, and Increases Fertility in Midlife Female SAMP8 Mice

Women of advanced maternal age (AMA) (age ≥ 35) have increased rates of infertility, miscarriages, and trisomic pregnancies. Collectively these conditions are called "egg infertility." A root cause of egg infertility is increased rates of oocyte aneuploidy with age. AMA women often have elevated endogenous FSH. Female senescence-accelerated mouse-prone-8 (SAMP8) has increased rates of oocyte spindle aberrations, diminished fertility, and rising endogenous FSH with age. We hypothesize that elevated FSH during the oocyte's FSH-responsive growth period is a cause of abnormalities in the meiotic spindle. We report that eggs from SAMP8 mice treated with equine chorionic gonadotropin (eCG) for the period of oocyte growth have increased chromosome and spindle misalignments. Activin is a molecule that raises FSH, and ActRIIB:Fc is an activin decoy receptor that binds and sequesters activin. We report that ActRIIB:Fc treatment of midlife SAMP8 mice for the duration of oocyte growth lowers FSH, prevents egg chromosome and spindle misalignments, and increases litter sizes. AMA patients can also have poor responsiveness to FSH stimulation. We report that although eCG lowers yields of viable oocytes, ActRIIB:Fc increases yields of viable oocytes. ActRIIB:Fc and eCG cotreatment markedly reduces yields of viable oocytes. These data are consistent with the hypothesis that elevated FSH contributes to egg aneuploidy, declining fertility, and poor ovarian response and that ActRIIB:Fc can prevent egg aneuploidy, increase fertility, and improve ovarian response. Future studies will continue to examine whether ActRIIB:Fc works via FSH and/or other pathways and whether ActRIIB:Fc can prevent aneuploidy, increase fertility, and improve stimulation responsiveness in AMA women.

Gonadotropin dose is negatively correlated with live birth rate: analysis of more than 650,000 assisted reproductive technology cycles

OBJECTIVE

To evaluate the correlation between total gonadotropin dose and live birth rate.

DESIGN

Retrospective analysis.

SETTING

Not applicable.

PATIENT(S)

A total of 658,519 fresh autologous cycles of in vitro fertilization (IVF) reported to the Society for Assisted Reproductive Technology from 2004 to 2012.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Logistic regression models were fitted to live birth rates with the use of categorized values for total FSH dose and number of oocytes retrieved as the primary predictor variables. To reduce the effect of the most significant confounders that may lead physicians to prescribe higher doses of FSH, additional analyses were performed limited to good-prognosis patients (<35 years of age, body mass index <30 kg/m(2), and no diagnosis of diminished ovarian reserve, endometriosis, or ovulatory disorder) and including duration of gonadotropin treatment.

RESULT(S)

Live birth rate significantly decreased with increasing FSH dose, regardless of the number of oocytes retrieved. The statistically significant decrease in live birth rate with increasing FSH dose remained in patients with good prognosis, and regardless of female age, except for women aged ≥ 35 years with 1-5 oocytes retrieved.

CONCLUSION(S)

This analysis suggests that physicians may wish to avoid prescribing a high dose of FSH. However, the results of this study do not justify the use of minimal-stimulation or natural-cycle IVF.

Meiosis and maternal aging: insights from aneuploid oocytes and trisomy births

In most organisms, genome haploidization requires reciprocal DNA exchanges (crossovers) between replicated parental homologs to form bivalent chromosomes. These are resolved to their four constituent chromatids during two meiotic divisions. In female mammals, bivalents are formed during fetal life and remain intact until shortly before ovulation. Extending this period beyond ∼35 years greatly increases the risk of aneuploidy in human oocytes, resulting in a dramatic increase in infertility, miscarriage, and birth defects, most notably trisomy 21. Bivalent chromosomes are stabilized by cohesion between sister chromatids, which is mediated by the cohesin complex. In mouse oocytes, cohesin becomes depleted from chromosomes during female aging. Consistent with this, premature loss of centromeric cohesion is a major source of aneuploidy in oocytes from older women. Here, we propose a mechanistic framework to reconcile data from genetic studies on human trisomy and oocytes with recent advances in our understanding of the molecular mechanisms of chromosome segregation during meiosis in model organisms.

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.

Is the mouse follicle culture a good model for the goat with respect to the development of preantral follicles in vitro?

The present study evaluated the efficiency of using 2 culture media developed for mice and for goats in the in vitro preantral follicle culture of each species. Murine and caprine secondary follicles were cultured in vitro with human recombinant follicle-stimulating hormone (murine medium) or with bovine recombinant follicle-stimulating hormone in association with growth hormone (caprine medium). The results showed that murine follicles cultured in caprine medium had lower (P < 0.05) rates of follicular survival and growth, whereas for caprine follicles, these variables were not affected by the type of medium used (P > 0.05). After in vitro maturation, a higher (P < 0.05) number of oocytes that resumed meiosis were observed in the murine medium for both species. In contrast, only in the caprine species estradiol production was significantly superior when the caprine medium was used. Higher progesterone production was observed in the presence of the murine medium only for murine follicles (P < 0.05). In conclusion, murine and caprine preantral follicles cultured under the same in vitro culture medium conditions respond differently; caprine oocytes grown in vitro in the presence of the murine medium show the greatest developmental competence among the tested combinations. Therefore, under the present experimental conditions, the mouse follicle culture has proved be a good model for the development of new culture media for caprine preantral follicles.

The phenotype of an IVF child is associated with peri-conception measures of follicular characteristics and embryo quality

STUDY QUESTION

Are childhood measures of phenotype associated with peri-conception parental, IVF treatment and/or embryonic characteristics of IVF children?

SUMMARY ANSWER

Birthweight, childhood body mass index (BMI) and height of pre-pubertal IVF children were strongly associated with peri-conception factors, including follicular and embryonic characteristics.

WHAT IS KNOWN ALREADY

A growing number of studies have identified a range of phenotypic differences between IVF and naturally conceived pre-pubertal children; for example, birthweights are lower following a fresh compared with a thawed embryo transfer.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study included IVF children (n = 96) born at term (>37 weeks) after a singleton pregnancy from the transfer of either fresh or thawed embryos in New Zealand. Between March 2004 and November 2008, these children were subjected to clinical assessment before puberty.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Clinical assessment provided anthropometric measures of children aged 3.5-11 years old. Peri-conception factors (n = 36) derived retrospectively from parental, treatment, laboratory and embryonic variables (n = 69) were analysed using multiple stepwise regression with respect to standard deviation scores (SDSs) of the birthweight, mid-parental corrected BMI and height of the IVF children. Data from children conceived from fresh (n = 60) or thawed (n = 36) embryos, that met inclusion criteria and had high-quality data with >90% completeness, were analysed.

MAIN RESULTS AND THE ROLE OF CHANCE

Embryo treatment at transfer was identified as a predictor of birthweight with thawed embryos resulting in heavier birthweights than fresh embryos [P = 0.02, 95% confidence interval (CI) fresh minus thawed: -1.047 to -0.006]. Birthweight SDS was positively associated with mid-parental corrected BMI SDS (P = 0.003, slope 0.339 ± 0.100). Four factors were related (P < 0.05) to mid-parental corrected height SDS. In particular, child height was inversely associated with the diameter of lead follicles at oocyte retrieval (P < 0.0001, slope -0.144 ± 0.040) and with the quality score of embryos at transfer (P = 0.0008, slope -0.425 ± 0.157), and directly associated with the number of follicles retrieved (P = 0.05, slope 1.011 ± 0.497). Child height was also positively associated with the transfer of a fresh as opposed to thawed embryo (P < 0.001, 95% CI 0.275-0.750).

LIMITATIONS, REASONS FOR CAUTION

More than one embryo was transferred in most cycles so mean development and quality data were used. The large number of variables measured was on a relatively small sample size. Large cohorts from multiple clinics using a variety of treatment protocols and embryology methods are needed to confirm the associations identified and ultimately to test these factors as possible predictors of phenotype.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to directly associate peri-conception measures of IVF treatment with a pre-pubertal child's phenotype. Demonstration that peri-conception measures relate to a pre-pubertal child's phenotype extends the range of factors that may influence growth and development. These findings, if corroborated by larger studies, would provide invaluable information for practitioners, who may want to consider the impact of ovarian stimulation protocols as well as the quality of the embryo transferred on a child's growth and development, in addition to their impact on pregnancy rate.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from the National Research Centre of Growth and Development New Zealand (grant 3682065) and the Australasian Paediatric Endocrine Group (APEG; grant 3621994), as well as a fellowship from Fertility Associates New Zealand awarded to M.P.G. In terms of competing interest, J.C.P is a shareholder of Fertility Associates. M.P.G. currently holds the position of Merck Serono Lecturer in Reproductive Biology. W.S.C. and P.L.H. have also received grants and non-financial support from Novo Nordisk, as well as personal fees from Pfizer that are unrelated to the current study. The other authors have no conflict of interest to declare.