Usefulness of oocyte accumulation in low ovarian response for PGS

Accumulated Vitrified Embryos Could Be a Method for Increasing Pregnancy Rates in Patients with Poor Ovarian Response

We aimed to assess the efficacy of accumulated embryo transfer (ACC-ET) through several controlled ovarian hyperstimulation (COS) cycles to increase the rates of pregnancy in patients with poor ovarian response (POR). We retrospectively reviewed the medical records of 588 patients with POR under 43-years old who underwent embryo transfer from January 2010 to December 2015. We compared the pregnancy rate (PR), clinical pregnancy rate (CPR), and live birth rate (LBR) between ACC-ET (frozen-thawed: 47; fresh + frozen-thawed: 24) group (n = 71) and fresh ET groups (n = 517). Characteristics of ACC-ET patients were similar to those of fresh ET groups (Age: 38.1 ± 3.5 vs. 38.2 ± 3.7, p = 0.88; Anti Müllerian Hormone (AMH; ng/mL): 0.5 ± 0.4 vs. 0.6 ± 0.6, p = 0.38; follicle stimulating hormone (FSH: mIU/mL): 11.9 ± 8.0 vs. 10.8 ± 9.0, p = 0.35). The total number of transferred embryos (3.1 ± 0.9 vs. 1.5 ± 0.7, p = 0.00), PR (29.6% (21/71) vs. 18.8% (97/517), p = 0.040), and CPR (23.5% (16/68) vs. 14.0% (71/508) p = 0.047) were significantly higher in the ACC-ET group than in the fresh ET group. In addition, PR, CPR, and LBR increased with the number of ET in the fresh ET group. However, there were no significant differences observed in LBR between ACC-ET and fresh ET groups (14.9% (10/67) vs. 9.8% (50/508), p = 0.203). From our knowledge, there is no clinical evidence reported to prove that transfer of multiple embryos of adequate quality obtained through multiple cycles can compensate for the limited number of retrieved oocytes from POR patients. We concluded that ACC-ET from several COS cycles could be an alternative method to increase PR and CPR in <43-year-old patients with POR.

Evaluating different strategies for poor ovarian response management: a retrospective cohort study and literature review

This retrospective study compares four different strategies for managing poor ovarian response (POR), namely, conventional stimulation (300 IUs) IVF-fresh embryo transfer (CONVF), mild stimulation (150 IUs) IVF-fresh embryo transfer (MILDF), mild stimulation embryo banking (MILDB), and embryo banking in natural cycles (NATB). In total, 796 POR patients were considered eligible. Statistical analysis revealed a shorter duration of stimulation and a lower required amount of gonadotropins in MILDF compared with CONVF (9.34 ± 1.17 versus 10.37 ± 1.14; 1402 ± 176 versus 3110 ± 343, P < 0.001). Comparing MILDF and MILDB, a higher number of available oocytes and embryos was observed in MILDB (2.36 ± 1.15 versus 6.58 ± 1.11; 1.72 ± 1.02 versus 3.51 ± 0.61, P < 0.001). Moreover, the MILDB presented with a lower number of required oocyte retrievals and a higher number of oocytes per oocyte retrieval compared with NATB (3.90 ± 1.56 versus 7.15 ± 1.80; 1.95 ± 0.74 versus 0.89 ± 0.20, P < 0.001). Data indicate that MILDF is equally efficient and associated with a shorter duration of stimulation and a lower required amount of gonadotropins compared with CONVF. Embryo accumulation may be more efficient compared with a fresh embryo transfer. MILDB may be a more efficient approach compared with NATB. To conclude, embryo accumulation following mild stimulation appears to form the optimal strategy for POR management. More studies are needed to verify these conclusions.

Anti-Müllerian hormone is an independent marker for oocyte survival after vitrification

RESEARCH QUESTION

This study explored the relationship between anti-Müllerian hormone (AMH) and oocyte survival after vitrification. The association between AMH and blastocyst formation after oocyte vitrification was also assessed.

DESIGN

A retrospective observational analysis was performed in a private IVF centre. A total of 4507 metaphase-II warmed oocytes were included from 450 couples, predominantly of Arab ethnicity. Between August 2015 and August 2018, couples underwent 484 intracytoplasmic sperm injection (ICSI) treatments using vitrified-warmed oocytes.

RESULTS

Patients' median age ± SD was 36.2 ± 6.1 years, AMH concentration 2.6 ± 3.4 ng/ml and body mass index (BMI) 26.5 ± 4.6 kg/m². The oocyte survival rate after vitrification was 87.37 ± 20.42%. AMH concentration showed a significant correlation (Kendall's tau 0.087, P = 0.0079) with oocyte survival rate independent of oocyte yield. Correlation was significant (odds ratio 1.041, 95% confidence interval 1.007-1.077, P = 0.018) when a multivariant model was applied that included AMH, age and BMI. The receiver operating characteristic curve showed an AMH cut-off value of 1.09 ng/ml that could obtain at least a 70% survival rate, with an area under the curve of 0.669. Regarding embryo development in ICSI cycles including fresh and warmed oocytes for the same patient, blastocyst formation rate was higher in fresh compared with warmed oocytes (P < 0.001). In this subgroup no significant correlation was seen between fertilization or blastocyst rate and AMH concentration.

CONCLUSIONS

AMH concentration showed a significant correlation with oocyte survival. Blastocyst formation was significantly lower after oocyte vitrification, but no correlation was found with AMH. Clinicians should carefully evaluate oocyte vitrification for patients with AMH below 1.09 ng/ml and consider embryo accumulation for these patients in preference to oocyte accumulation.

Ovarian stimulation for preimplantation genetic testing

A narrative review of the management of controlled ovarian stimulation in patients undergoing preimplantation genetic testing is presented. An electronic search was performed to identify research publications that addressed ovarian stimulation and preimplantation genetic testing published until December 2017. Studies were classified in decreasing categories: randomized controlled trials, prospective controlled trials, prospective non-controlled trials, retrospective studies and experimental studies. The aim of controlled ovarian stimulation has shifted from obtaining embryos available for transfer to yielding the maximum embryos available for biopsy to increase the odds of achieving one euploid embryo available for transfer, without the distress of inducing ovarian hyperstimulation syndrome or inadequate endometrium receptivity as vitrification and deferred embryo transfer usually will be planned. The present narrative review summarizes all treatment-related variables as well as stimulation strategies after controlled ovarian stimulation that could help patients undergoing an in vitro fertilization cycle coupled with preimplantation genetic testing, including the number of oocytes needed to achieve one healthy live birth, oral contraceptive pill usage, the role of mild ovarian stimulation or random-start stimulation, the stimulation protocol and type of gonadotropin of choice, the novel progesterone protocols, agonist or dual trigger as a final oocyte maturation trigger, the accumulation of oocytes/embryos and the optimal interval before proceeding with a subsequent controlled ovarian stimulation or the optimal medication to link stimulation cycles. The discussion is being presented according to how questions are posed in clinical practice. The aim of ovarian stimulation has shifted from obtaining embryos available for transfer to yielding the maximum embryos available for biopsy to increase the odds of achieving one euploid embryo available for transfer.

Advanced Maternal Age in IVF: Still a Challenge? The Present and the Future of Its Treatment

Advanced maternal age (AMA; >35 year) is associated with a decline in both ovarian reserve and oocyte competence. At present, no remedies are available to counteract the aging-related fertility decay, however different therapeutic approaches can be offered to women older than 35 year undergoing IVF. This review summarizes the main current strategies proposed for the treatment of AMA: (i) oocyte cryopreservation to conduct fertility preservation for medical reasons or "social freezing" for non-medical reasons, (ii) personalized controlled ovarian stimulation to maximize the exploitation of the ovarian reserve in each patient, (iii) enhancement of embryo selection via blastocyst-stage preimplantation genetic testing for aneuploidies and frozen single embryo transfer, or (iv) oocyte donation in case of minimal/null residual chance of pregnancy. Future strategies and tools are in the pipeline that might minimize the risks of AMA through non-invasive approaches for embryo selection (e.g., molecular analyses of leftover products of IVF, such as spent culture media). These are yet challenging but potentially ground-breaking perspectives promising a lower clinical workload with a higher cost-effectiveness. We also reviewed emerging experimental therapeutic approaches to attempt at restoring maternal reproductive potential, e.g., spindle-chromosomal complex, pronuclear or mitochondrial transfer, and chromosome therapy. In vitro generation of gametes is also an intriguing challenge for the future. Lastly, since infertility is a social issue, social campaigns, and education among future generations are desirable to promote the awareness of the impact of age and lifestyle habits upon fertility. This should be a duty of the clinical operators in this field.

Characterization of a suboptimal IVF population and clinical outcome after two IVF cycles

The number of oocytes retrieved in in vitro fertilization (IVF) cycles is an independent factor influencing pregnancy rate (PR), and optimal number of oocytes would be between 10 and 15. This has led to the hypothesis that the identification of a suboptimal group of responders beforehand (4-9 oocytes retrieved) would allow physicians to optimize their PR. A retrospective observational study counting on 735 women doing an IVF treatment in our center was performed. Multivariable logistic regression was used to analyze the relationship between anti-Mullerian hormone (AMH) and antral follicle count (AFC), within suboptimal and optimal responders. We also analyzed the outcome of those patients with an estimated high probability of having an optimal response and the second cycles of those who did not get pregnant in the first cycle to observe the main significant traits that made them change from one group of responders to the other. Main results are that suboptimal responders account for almost half of our patients. Ovarian reserve markers (AMH and AFC) are significantly different in optimal and suboptimal responders, even when adjusted by age. There is a significant difference in the cumulative PR between both groups. Interestingly, 18.9% shifted from suboptimal to optimal response, and 36.9% from optimal to suboptimal.