The complex relationship between female age and embryo euploidy

The comparision among euploidy of preimplantation blastocysts in different controlled ovary stimulation (COH) protocols

PURPOSE

To compare differences in euploidy rates for blastocysts in preimplantation genetic testing for aneuploidy (PGT-A) cycles after gonadotropin-releasing hormone agonist (GnRH-a) long and short protocols, GnRH-antagonist (GnRH-ant) protocol, progestin-primed ovarian stimulation and mild stimulation protocols, and other ovary stimulation protocols.

METHODS

This was a retrospective cohort study from the Assisted Reproductive Medicine Department of Shanghai First Maternity and Infant Hospital. A total of 1657 PGT-A cycles with intracytoplasmic sperm injection after different controlled ovary hyperstimulation protocols were analyzed, and a total of 3154 embryos were biopsied. Differences in euploidy rate per embryo biopsied, embryo euploidy rate per oocyte retrieved and cycle cancellation rate were compared.

RESULTS

For the PGT-A cycles, the euploidy rate per embryo biopsied was lower in the GnRH-ant protocol than in the GnRH-a long protocol (53.26 vs. 58.68%, respectively). Multiple linear regression showed that the GnRH-ant protocol was associated with a lower euploidy rate per embryo biopsied (β =  -0.079, p = 0.011). The euploidy rate per embryo biopsied was not affected by total gonadotropin dosage, duration of stimulation and number of oocytes retrieved. The embryo euploidy rate per oocyte retrieved was similar in all protocols and was negatively correlated with the total number of oocytes retrieved (β =  -0.003, p = 0.003).

CONCLUSION

Compared with the GnRH-a long protocol, the GnRH-ant protocol was associated with a lower euploidy rate per embryo biopsied. The total gonadotropin dosage, duration of stimulation and number of oocytes retrieved did not appear to significantly influence euploidy rates.

Factors affecting the reproductive outcome in reciprocal translocation carriers undergoing preimplantation genetic testing for structural rearrangements (PGTSR)

OBJECTIVE

To investigate the reproductive outcomes of balanced reciprocal translocation carriers and evaluate the association between the number of metaphase-II oocytes retrieved and cumulative live birth rates (LBRs).

METHODS

This retrospective analysis included 344 preimplantation genetic testing (PGT) for structural rearrangement cycles of 281 couples with balanced reciprocal translocations between January 2018 and January 2021. All patients included in the analysis had either delivered a baby or had used all their embryos after one stimulation cycle. All women were followed up for at least 2 years.

RESULTS

After ovarian stimulation and oocyte fertilization, 44.2% of PGT for structural rearrangements cycles achieved a live birth. Carrier's sex and female age did not affect the cumulative LBR of reciprocal translocation carriers. Cumulative LBRs steadily increased with the number of oocytes, reaching 64% when >20 oocytes were retrieved. The cutoff values for achieving at least one live birth were 9.5 metaphase-II (MII) oocytes and 3.5 biopsied embryos.

CONCLUSION

Couples with reciprocal translocations have lower transferable embryo rates and cumulative LBRs. The MII oocytes retrieved may be a crucial factor for cumulative LBRs. A high ovarian response may further increase cumulative LBRs, but avoidance of ovarian hyperstimulation syndrome or other iatrogenic complications should be considered.

The mosaic embryo: what it means for the doctor and the patient

INTRODUCTION

Mosaic embryos are embryos that on preimplantation genetic analysis are found to be composed of euploid and aneuploid cells. Although most of these embryos do not implant when transferred into the uterus following IVF treatment, some may implant and are capable of giving rise to babies.

EVIDENCE ACQUISITION

There is currently an increasing number of reports of live births following the transfer of mosaic embryos. Compared to euploid, mosaic embryos have lower implantation rates and higher rates of miscarriage, and occasionally aneuploid component persists. However, their outcome is better than that obtained after the transfer of embryos consisting entirely of aneuploid cells. After implantation, the ability to develop into a full-term pregnancy is influenced by the amount and type of chromosomal mosaicism present in a mosaic embryo. Nowadays many experts in the reproductive field consider mosaic transfers as an option when no euploid embryos are available. Genetic counseling is an important part of educating patients about the likelihood of having a pregnancy with healthy baby but also on the risk that mosaicism could persist and result in liveborn with chromosomal abnormality. Each situation needs to be assessed on a case-by-case basis and counseled accordingly.

EVIDENCE SYNTHESIS

So far, the transfers of 2155 mosaic embryos have been documented and 440 live births resulting in healthy babies have been reported. In addition, in the literature to date, there are 6 cases in which embryonic mosaicism persisted.

CONCLUSIONS

In conclusion, the available data indicate that mosaic embryos have the potential to implant and develop into healthy babies, albeit with lower success rates than euploids. Further clinical outcomes should be collected to better establish a refined ranking of embryos to transfer.

Does ICSI outcome in obstructive azoospermia differ according to the origin of retrieved spermatozoa or the cause of epididymal obstruction? A comparative study

Purpose

To determine whether ICSI outcomes are affected by sperm source or genital tract inflammatory status.

Methods

A retrospective cohort study was conducted in all consecutive obstructive azoospermia patients who underwent testicular sperm aspiration (TESA) or percutaneous epididymal sperm aspiration (PESA) and ICSI between February 1, 2017, and December 31, 2020. Couples were excluded if they were diagnosed with monogenic disease, abnormal karyotype, or had female uterine malformation. The primary objective was to determine whether ICSI outcomes are affected by the use of testicular or epididymal spermatozoa, and the secondary objective was to explore the effect of granulocyte elastase on ICSI outcomes using epididymal spermatozoa.

Results

Compared with TESA, inflammatory and non-inflammatory PESA patients exhibited a better high-quality embryo rate, with significant differences among the three groups (49.43 vs. 55.39% and 56.03%; odds ratio, 6.345 and 6.631; 95% confidence interval, 0.340–12.350, and 1.712–11.550; P = 0.038 and P = 0.008, respectively). The fertilization rate, clinical pregnancy rate, live birth delivery rate, and congenital anomaly birth rate were similar in patients who underwent TESA or PESA (with or without inflammation).

Conclusions

The high-quality embryo rate in PESA patients was higher than that in TESA patients. After successful pregnancy, ICSI outcomes did not differ between patients with obstructive azoospermia who experienced TESA or PESA and those with or without genital tract inflammation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11255-022-03350-x.

The number and rate of euploid blastocysts in women undergoing IVF/ICSI cycles are strongly dependent on ovarian reserve and female age

STUDY QUESTION

Can the possibility of having at least one euploid blastocyst for embryo transfer and the total number of euploid blastocysts be predicted for couples before they enter the IVF programme?

SUMMARY ANSWER

Ovarian reserve and female age are the most important predictors of having at least one euploid blastocyst and the total number of euploid blastocysts.

WHAT IS KNOWN ALREADY

The blastocyst euploidy rate among women undergoing ART has already been shown to significantly decrease with increasing female age, and the total number of euploid embryos is dependent on the blastocyst cohort size. However, the vast majority of published studies are based on retrospective analysis of data.

STUDY DESIGN, SIZE, DURATION

This prospective analysis included 847 consecutively enrolled couples approaching their first preimplantation genetic testing for aneuploidies (PGT-A) cycle between 2017 and 2020. Only couples for whom ejaculated sperm was available and women with a BMI of <35 kg/m2 were included in the study. Only the first cycle was included for each patient.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study was conducted at an IVF centre where, for all patients, the planned treatment was to obtain embryos at the blastocyst stage for the PGT-A programme. The impact of the following covariates was investigated: a woman's serum AMH level, age, height, weight and BMI and a man's age, height, weight, BMI, sperm volume and sperm motility and morphology. The analysis was performed with a machine learning (ML) approach. Models were fit on the training set (677 patients) and their predictive performance was then evaluated on the test set (170 patients).

MAIN RESULTS AND ROLE OF CHANCE

After ovarian stimulation and oocyte insemination, 40.1% of couples had at least one blastocyst available for the PGT-A. Of 1068 blastocysts analysed, 33.6% were euploid. Two distinct ML models were fit: one for the probability of having at least one euploid blastocyst and one for the number of euploid blastocysts obtained. In the training set of patients, the variable importance plots of both models indicated that AMH and the woman's age are by far the most important predictors. Specifically, a positive association between the outcome and AMH and a negative association between the outcome and female age appeared. Gradient-boosted modelling offers a greater predictive performance than generalized additive models (GAMs).

LIMITATIONS, REASONS FOR CAUTION

The study was performed based on data from a single centre. While this provides a robust set of data with a constant ART process and laboratory practice, the model might be suitable only for the evaluated population, which may limit the generalization of the model to other populations.

WIDER IMPLICATIONS OF THE FINDINGS

ML models indicate that for couples entering the IVF/PGT-A programme, ovarian reserve, which is known to vary with age, is the most important predictor of having at least one euploid embryo. According to the GAM, the probability of a 30-year-old woman having at least one euploid embryo is 28% or 47% if her AMH level is 1 or 3 ng/ml, respectively; if the woman is 40 years old, this probability is 18% with an AMH of 1 ng/ml and 30% with an AMH of 3 ng/ml.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by an unrestricted grant from Gedeon Richter. The authors declared no conflict of interests.

TRIAL REGISTRATION NUMBER

N/A.

Women in Advanced Reproductive Age: Are the Follicular Output Rate, the Follicle-Oocyte Index and the Ovarian Sensitivity Index Predictors of Live Birth in an IVF Cycle?

(1) Background: Several researchers have investigated alternative markers related to ovarian responsiveness in order to better predict IVF outcomes, particularly in advanced reproductive-aged women. The follicular output rate (FORT), the follicle-oocyte index (FOI) and the ovarian sensitivity index (OSI) are among the most promising. However, these three metrics have not been investigated as independent predictors of live birth in women of advanced reproductive age; neither have they been compared to the two ‘component’ characteristics that are used to calculate them. (2) Methods: A logistic regression model containing all relevant predictors of ovarian reserve or response was used to evaluate the potential of FORT, FOI and OSI as predictors of live birth. After, the non-linear associations between FORT, FOI and OSI and the probability of live birth were evaluated. Finally, we fitted multiple logistic regression models to compare whether FORT, FOI and OSI were more informative predictors than their components. (3) Results: 590 couples received a total of 740 IVF cycles, after which, 127 (17.5%) obtained a live birth. None of FORT, FOI and OSI showed a strength of association or a p-value even close to female age (odds ratio for live birth (95% confidence interval) 1.00 (0.99–1.01), 1.00 (0.99–1.01), 0.98 (0.88–1.11) and 0.58 (0.48–0.72), respectively). The three models comparing FORT, FOI and OSI with the number of oocytes retrieved, the AFC, the number of preovulatory follicles and the FSH total dose were not more informative. (4) Conclusions: In a population of women of advanced age with unexplained infertility, none of FORT, FOI and OSI were predictive of live birth or more predictive than the two ‘component’ characteristics that were used to calculate them. We suggest clinicians and researchers still use female age as the most reliable predictor of an IVF treatment.

Peripheral mitochondrial DNA, telomere length and DNA methylation as predictors of live birth in in vitro fertilization cycles

OBJECTIVE

To evaluate whether telomere length (TL), mitochondrial-DNA (mt-DNA) or epigenetic age estimators based on DNA methylation (DNAm) pattern could be considered reliable predictors of in-vitro-fertilization (IVF) success in terms of live birth rate.

DESIGN

Prospective cohort study.

SETTING

Infertility Unit of the Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico.

PATIENTS

181 women aged 37-39 years who underwent IVF at a single-centre between January 2017 and December 2018.

INTERVENTIONS

On the day of recruitment, blood samples were collected, and genomic DNA was isolated from white blood cells. TL, mt-DNA and DNAm assessment was performed using quantitative real-time polymerase chain reaction (qPCR). Biological age (DNAm age) was computed as the algorithm based on methylation pattern of five genes. Epigenetic age acceleration was estimated from the residuals of the linear model of epigenetic age regressed on chronological age. Long Interspersed Nuclear Elements (LINE)-1 methylation pattern was used as a surrogate for global DNA methylation.

MAIN OUTCOME MEASURES

This study investigated whether peripheral TL, mt-DNA and DNAm could predict live birth in IVF cycles.

RESULTS

TL, mt-DNA and LINE-1 methylation were not associated with IVF success. Conversely, DNAm age resulted significantly lower in women who had a live birth compared to women who did not (36.1 ± 4.2 and 37.3 ± 3.3 years, respectively, p = 0.04). For DNAm age, odds ratio (OR) for live birth per year of age was 0.90 (95%CI: 0.82-0.99, p = 0.036) after adjusting for FSH and antral follicle count (AFC) and 0.90 (95%CI: 0.82-0.99, p = 0.028) after adjusting also for number of oocytes retrieved. A significant association also emerged for epigenetic age acceleration after adjustments (OR = 0.91, 95%CI: 0.83-1.00, p = 0.048).

CONCLUSION

DNAm age is associated with IVF success but the magnitude of this association is insufficient to claim a clinical use. However, our findings are promising and warrant further investigation. Assessment of biological age using different epigenetic clocks or focusing on different tissues may reveal new predictors of IVF success.

Increased Systemic Antioxidant Power Ameliorates the Aging-Related Reduction in Oocyte Competence in Mice

Ovarian aging is associated with elevated oxidative stress and diminished oocyte developmental competence. We aimed to determine the impact of systemic antioxidant treatment in aged mice. Female outbred CF-1 mice were aged for 9 months prior to an 8-week 45 mg Euterpe oleracea (açaí) daily supplement. The açaí treatment induced a threefold increase in serum antioxidant power (FRAP) compared to both young and aged mice (p < 0.0001). Compared to young mice, aged mice had fewer oocytes and reduced blastocyst development (p < 0.0001); açaí did not affect the oocyte numbers, but improved blastocyst formation (p < 0.05). Additionally, açaí alleviated the aging-related decrease in implantation potential (p < 0.01). The aged mice showed evidence of elevated ovarian ER stress (increased whole-ovary PDIA4 expression, granulosa cell and oocyte GRP78 expression, and oocyte PDIA4 protein), reduced oocyte mitochondrial quality (higher PRKN activation and mitochondrial DNA oxidative damage), and dysregulated uterine glandular epithelium. Antioxidant intervention was sufficient to lessen these effects of ovarian aging, likely in part by the upregulation of NRF2. We conclude that açaí treatment is a promising strategy to improve ER and mitochondrial function in the ovaries, thereby ameliorating the decreased oocyte competence that occurs with ovarian aging.