Reproductive outcome is optimized by genomic embryo screening, vitrification, and subsequent transfer into a prepared synchronous endometrium

Obstetric outcomes of nulliparous women with pelvic pain undergoing fertility treatment

RESEARCH QUESTION

Is there any association between pelvic pain and primary caesarean delivery for patients undergoing assisted reproductive technology (ART) treatment?

DESIGN

Retrospective cohort study of nulliparous patients with singleton pregnancies who underwent ART treatment and achieved a live birth between 2012 and 2020. Cases included patients diagnosed with pelvic pain. A 3:1 ratio propensity-score-matched population of patients without a history of pelvic pain was included as the control group. Comparative statistics were performed using chi-squared test and Student's t-test. A multivariate regression analysis was conducted to evaluate the association between pelvic pain and mode of delivery.

RESULTS

One hundred and seventy-four patients with pelvic pain were compared with 575 controls. Patients with pelvic pain reported a significantly longer duration of infertility compared with controls (18.98 ± 20.2 months versus 14.06 ± 14.06 months; P = 0.003). Patients with pelvic pain had a significantly higher rate of anxiety disorders (115 ± 21.9 versus 55 ± 31.6; P = 0.009) and use of anxiolytics at embryo transfer (17 ± 3.2 versus 12 ± 6.9; P = 0.03) compared with controls. In addition, patients with pelvic pain had a higher rate of primary caesarean delivery compared with controls (59.8% versus 49.0%; P = 0.01). After adjusting for multiple variables, a significant association was found between pelvic pain and increased odds of primary caesarean delivery (adjusted OR 1.48, 95% CI 1.02-2.1).

CONCLUSION

Patients with pelvic pain have significantly higher odds of primary caesarean delivery compared with patients without a history of pelvic pain. The infertility outpatient setting may be uniquely positioned to identify patients at risk for undergoing primary caesarean delivery, and could facilitate earlier intervention for pelvic floor physical therapy during the preconception and antepartum periods.

The use of preimplantation genetic testing for aneuploidy: a committee opinion

The use of preimplantation genetic testing for aneuploidy (PGT-A) in the United States has been increasing steadily. Moreover, the underlying technology used for 24-chromosome analysis continues to evolve rapidly. The value of PGT-A as a routine screening test for all patients undergoing in vitro fertilization has not been demonstrated. Although some earlier single-center studies reported higher live-birth rates after PGT-A in favorable-prognosis patients, recent multicenter, randomized control trials in women with available blastocysts concluded that the overall pregnancy outcomes via frozen embryo transfer were similar between PGT-A and conventional in vitro fertilization. The value of PGT-A to lower the risk of clinical miscarriage is also unclear, although these studies have important limitations. This document replaces the document of the same name, last published in 2018.

Spironolactone use and oocyte maturation in patients undergoing controlled ovarian hyperstimulation

PURPOSE

To evaluate the association between spironolactone use and controlled ovarian hyperstimulation (COH) outcomes.

METHODS

Retrospective study, including patients who underwent COH. Oocyte yield and maturation rates were compared by categories of spironolactone use at the start of their cycle.

RESULTS

402 patients were included. 83 patients continued spironolactone, 44 patients discontinued spironolactone, and 275 matched control patients were spironolactone-naïve. No difference was observed in the number of oocytes retrieved (17 ± 14 vs. 15 ± 13, p = 0.4) or mature oocytes vitrified (15 ± 9.5 vs. 12 ± 11, p = 0.4) in patients who continued spironolactone use and spironolactone naïve patients, respectively. When comparing patients who continued spironolactone use and patients who discontinued spironolactone use, no difference was seen in the number of oocytes retrieved (17 ± 14 vs. 17.5 ± 7.8, p = 0.9) or mature oocytes vitrified (15 ± 9.5 vs. 13.5 ± 6.5, p = 0.5), respectively. There was no observed relationship between total daily spironolactone dose (< 100mg/day, 100mg/day, 150mg/day and > 200 mg/day) and the total number of mature oocytes vitrified (respectively, 14.0 ± 13.0, 16.0 ± 7.8, 14.0 ± 4.5, 11.0 ± 7.0 oocytes, p = 0.4).

CONCLUSIONS

This is the first study to evaluate the association between spironolactone and oocyte yield and maturation rates during COH cycles. These findings can assist in counseling patients on the implications of continuing spironolactone during COH cycle.

Fertility treatment outcomes in transgender men with a history of testosterone therapy

Objective

To evaluate fertility treatment outcomes among transgender (TG) men with a history of gender-affirming hormone therapy with exogenous testosterone.

Design

Descriptive, retrospective cohort study.

Patients

Transgender men with a history of gender-affirming hormone therapy with exogenous testosterone underwent fertility treatments, including embryo cryopreservation, in vitro fertilization (IVF), co-IVF, oocyte cryopreservation, and intrauterine insemination (IUI), between 2013 and 2021.

Intervention

Gender-affirming hormone therapy with testosterone.

Main Outcome Measures

Live births (LBs), number of frozen embryos, and number of frozen oocytes. Other outcome measures included total gonadotropin used, peak estradiol levels, oocytes retrieved, oocyte maturity rate, fertilization rate, and embryo grade.

Results

A total of 77 TG men self-presented or were referred to care at a single academic fertility center, of which 46 (59.7%) TG men underwent fertility preservation and/or family-building counseling, with 16 (20.8%) patients proceeding to fertility treatment. Of those patients who underwent treatment, 11 (68.8%) had a history of gender-affirming hormone therapy with exogenous testosterone use. Cohort 1 included IVF (n = 1), co-IVF (n = 1), embryo cryopreservation (n = 2), cohort 2 included oocyte cryopreservation (n = 4), and cohort 3 included IUI (n = 3). In cohort 1, both the patients who underwent IVF and the patients who underwent co-IVF achieved LBs. All embryo cryopreservation cycles froze three or more embryos. In cohort 2, the average number of frozen mature oocytes was 19.3 ± 16.2 (range 6-43). All patients who underwent IUI cycles achieved LB.

Conclusion

In this study, no correlation existed between patient age, time on or off gender-affirming hormone therapy with exogenous testosterone, total gonadotropin used, and number of oocytes retrieved. All patients who completed IVF or embryo cryopreservation produced high-quality blastocytes, and this is the first study to show successful IUI cycles in patients with a history of gender-affirming hormone therapy with exogenous testosterone. This study demonstrates that TG men who have used gender-affirming hormone therapy previously can successfully undergo fertility treatments to attain oocyte and embryo cryopreservation, pregnancy, and LBs.

A systematic review and meta-analysis: clinical outcomes of recurrent pregnancy failure resulting from preimplantation genetic testing for aneuploidy

Background

Preimplantation genetic testing for aneuploidy (PGT-A) is an emerging technology that aims to identify euploid embryos for transfer, reducing the risk of embryonic chromosomal abnormalities. However, the clinical benefits of PGT-A in recurrent pregnancy failure (RPF) patients, particularly in young RPF patients, remains uncertain.

Objective and rationale

This meta-analysis aimed to determine whether RPF patients undergoing PGT-A had better clinical outcomes compared to those not undergoing PGT-A, thus assessing the value of PGT-A in clinical practice.

Search methods

We systematically searched PubMed, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Data, and VIP Database for Chinese Technical Periodicals (VIP) from 2002 to 2022. Thirteen published studies involving 930 RPF patients screened using PGT-A and over 1,434 RPF patients screened without PGT-A were included in this meta-analysis. Clinical outcomes were evaluated based on embryo transfers after PGT-A (n=1,015) and without PGT-A (n=1,799).

Clinical outcomes

The PGT-A group demonstrated superior clinical outcomes compared to the in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) group. The PGT-A group had a significantly higher implantation rate (IR) (RR=2.01, 95% CI: [1.73; 2.34]), clinical pregnancy rate (CPR) (RR=1.53, 95% CI: [1.36; 1.71]), ongoing pregnancy rate (OPR) (RR=1.76, 95% CI: [1.35; 2.29]), live birth rate (LBR) (RR=1.75, 95% CI: [1.51; 2.03]), and significantly lower clinical miscarriage rate (CMR) (RR=0.74, 95% CI: [0.54; 0.99]). Subgroup analysis based on patient age (under 35 years and 35 years or older) showed that both PGT-A subgroups had significantly better CPR (P<0.01) and LBR (P<0.05) values compared to the IVF/ICSI groups.

Summary

This meta-analysis demonstrates that PGT-A in RPF patients, is associated with improved clinical outcomes, including higher IR, CPR, OPR, and LBR values, and lower CMR compared to the IVF/ICSI group. These findings support the positive clinical application of PGT-A in RPF patients.

Systematic Review Registration

http://INPLASY.com, identifier INPLASY 202320118.

Opening the black box: why do euploid blastocysts fail to implant? A systematic review and meta-analysis

BACKGROUND

A normal chromosomal constitution defined through PGT-A assessing all chromosomes on trophectoderm (TE) biopsies represents the strongest predictor of embryo implantation. Yet, its positive predictive value is not higher than 50-60%. This gap of knowledge on the causes of euploid blastocysts' reproductive failure is known as 'the black box of implantation'.

OBJECTIVE AND RATIONALE

Several embryonic, maternal, paternal, clinical, and IVF laboratory features were scrutinized for their putative association with reproductive success or implantation failure of euploid blastocysts.

SEARCH METHODS

A systematic bibliographical search was conducted without temporal limits up to August 2021. The keywords were '(blastocyst OR day5 embryo OR day6 embryo OR day7 embryo) AND (euploid OR chromosomally normal OR preimplantation genetic testing) AND (implantation OR implantation failure OR miscarriage OR abortion OR live birth OR biochemical pregnancy OR recurrent implantation failure)'. Overall, 1608 items were identified and screened. We included all prospective or retrospective clinical studies and randomized-controlled-trials (RCTs) that assessed any feature associated with live-birth rates (LBR) and/or miscarriage rates (MR) among non-mosaic euploid blastocyst transfer after TE biopsy and PGT-A. In total, 41 reviews and 372 papers were selected, clustered according to a common focus, and thoroughly reviewed. The PRISMA guideline was followed, the PICO model was adopted, and ROBINS-I and ROB 2.0 scoring were used to assess putative bias. Bias across studies regarding the LBR was also assessed using visual inspection of funnel plots and the trim and fill method. Categorical data were combined with a pooled-OR. The random-effect model was used to conduct the meta-analysis. Between-study heterogeneity was addressed using I2. Whenever not suitable for the meta-analysis, the included studies were simply described for their results. The study protocol was registered at http://www.crd.york.ac.uk/PROSPERO/ (registration number CRD42021275329).

OUTCOMES

We included 372 original papers (335 retrospective studies, 30 prospective studies and 7 RCTs) and 41 reviews. However, most of the studies were retrospective, or characterized by small sample sizes, thus prone to bias, which reduces the quality of the evidence to low or very low. Reduced inner cell mass (7 studies, OR: 0.37, 95% CI: 0.27-0.52, I2 = 53%), or TE quality (9 studies, OR: 0.53, 95% CI: 0.43-0.67, I2 = 70%), overall blastocyst quality worse than Gardner's BB-grade (8 studies, OR: 0.40, 95% CI: 0.24-0.67, I2 = 83%), developmental delay (18 studies, OR: 0.56, 95% CI: 0.49-0.63, I2 = 47%), and (by qualitative analysis) some morphodynamic abnormalities pinpointed through time-lapse microscopy (abnormal cleavage patterns, spontaneous blastocyst collapse, longer time of morula formation I, time of blastulation (tB), and duration of blastulation) were all associated with poorer reproductive outcomes. Slightly lower LBR, even in the context of PGT-A, was reported among women ≥38 years (7 studies, OR: 0.87, 95% CI: 0.75-1.00, I2 = 31%), while obesity was associated with both lower LBR (2 studies, OR: 0.66, 95% CI: 0.55-0.79, I2 = 0%) and higher MR (2 studies, OR: 1.8, 95% CI: 1.08-2.99, I2 = 52%). The experience of previous repeated implantation failures (RIF) was also associated with lower LBR (3 studies, OR: 0.72, 95% CI: 0.55-0.93, I2 = 0%). By qualitative analysis, among hormonal assessments, only abnormal progesterone levels prior to transfer were associated with LBR and MR after PGT-A. Among the clinical protocols used, vitrified-warmed embryo transfer was more effective than fresh transfer (2 studies, OR: 1.56, 95% CI: 1.05-2.33, I2 = 23%) after PGT-A. Lastly, multiple vitrification-warming cycles (2 studies, OR: 0.41, 95% CI: 0.22-0.77, I2 = 50%) or (by qualitative analysis) a high number of cells biopsied may slightly reduce the LBR, while simultaneous zona-pellucida opening and TE biopsy allowed better results than the Day 3 hatching-based protocol (3 studies, OR: 1.41, 95% CI: 1.18-1.69, I2 = 0%).

WIDER IMPLICATIONS

Embryo selection aims at shortening the time-to-pregnancy, while minimizing the reproductive risks. Knowing which features are associated with the reproductive competence of euploid blastocysts is therefore critical to define, implement, and validate safer and more efficient clinical workflows. Future research should be directed towards: (i) systematic investigations of the mechanisms involved in reproductive aging beyond de novo chromosomal abnormalities, and how lifestyle and nutrition may accelerate or exacerbate their consequences; (ii) improved evaluation of the uterine and blastocyst-endometrial dialogue, both of which represent black boxes themselves; (iii) standardization/automation of embryo assessment and IVF protocols; (iv) additional invasive or preferably non-invasive tools for embryo selection. Only by filling these gaps we may finally crack the riddle behind 'the black box of implantation'.

Assessing the clinical viability of micro 3 pronuclei zygotes

PURPOSE

What is the rate of euploidy and clinical viability of embryos resulting from micro 3 pronuclei zygotes?

METHODS

Retrospective cohort analysis in a single, academic in vitro fertilization (IVF) center from March 2018 to June 2021. Cohorts were separated by fertilization as either a 2 pronuclear zygote (2PN) or micro 3 pronuclear zygote (micro 3PN). PGT-A was performed to identify embryonic ploidy rates in embryos created from micro 3PN zygotes. The clinical outcomes of all transferred euploid micro 3PN zygotes were evaluated from frozen embryo transfer (FET) cycles.

RESULTS

During the designated study period, 75,903 mature oocytes were retrieved and underwent ICSI. Of these, 60,161 were fertilized as 2PN zygotes (79.3%) and 183 fertilized as micro 3PN zygotes (0.24%). Of the micro 3PN-derived embryos that underwent biopsy, 27.5% (n=11/42) were deemed euploid by PGT-A, compared to 51.4% (n=12,301/23,923) of 2PN-derived embryos, p=0.06. Four micro 3PN-derived embryos were transferred in subsequent single euploid FET cycles, which includes one live birth and one ongoing pregnancy.

CONCLUSION

Micro 3PN zygotes that develop to the blastocyst stage and meet the criteria for embryo biopsy have the potential to be euploid by preimplantation genetic testing for aneuploidy (PGT-A) and if selected for transfer can achieve a live birth. Although there are a significantly lower number of micro 3PN embryos that make it to blastocyst biopsy, the potential to continue to culture abnormally fertilized oocytes may give these patients a chance at pregnancy that they previously did not have.

A randomised control trial on oral dydrogesterone versus micronized vaginal progesterone pessary for luteal phase support in in vitro fertilization cycles

This study aimed to evaluate the pregnancy rates, adverse reactions, and medication costs of two luteal phase support regimens: oral dydrogesterone and micronized vaginal progesterone (MVP) pessary in in vitro fertilization cycles. A randomized open-label trial with participants randomly assigned to either 400 mg MVP twice daily or 10 mg dydrogesterone three times daily. The primary endpoints were pregnancy rates, and the secondary endpoints included tolerance, miscarriage rates, and medication cost. Per-protocol principle analysis was performed. The baseline characteristics of the 162 participants were similar. Dydrogesterone had statistically similar (p>0.05) positive pregnancy test rates fifteen days post embryo transfer (35.8% vs. 32.7%), clinical pregnancy rates at the gestational age of 6 weeks (32.1% vs. 28.8%), ongoing pregnancy rates (26.4% vs. 23.1%) and miscarriage rates at 14 weeks of gestation (9.2% vs. 9.4%) and safety profile to MVP. Dydrogesterone was better tolerated as vaginal itching was significantly more prevalent in the MVP arm (p=0.008). Dydrogesterone is significantly less expensive than MVP pessary. Oral dydrogesterone and MVP pessary had similar pregnancy rates and adverse effects. Dydrogesterone appears more user-friendly and less expensive in cases of luteal-phase support in in vitro fertilization cycles.

Administration of depot GnRH agonist prior to programmed frozen-thawed embryo transfer does not improve the live birth rate in ovulatory women: A large, multi-center retrospective study

Despite that gonadotropin-releasing hormone (GnRH) agonist pretreatment has been widely used before programmed frozen-thawed transfer (FET), its impact on live birth rates in ovulatory women remains uncertain. In the present study, we aim to determine if GnRH agonists pretreatment before FET improves live birth rates in women undergoing in vitro fertilization with FET. Programmed FET cycles conducted in four infertility centers were retrospectively collected and reviewed for eligibility from January 2016 and December 2017. Patient's demographics, ovarian stimulation parameters, and pregnancy outcomes were compared between those given GnRH agonist pretreatment versus no pretreatment in ovulatory women undergoing FET cycles. A total of 6397 programmed cycles were screened for eligibility, of which 5049 cycles were included in the study for analysis. Compared with the group of no GnRH agonist pretreatment (n = 4143), women in the GnRH agonist group (n = 906) were older (33.0 vs 34.0, P < .001), had a higher proportion of subjects with previous transfer attempts and had a higher number of embryos transferred. After controlling for confounders, the logistic regression results showed that GnRH agonist pretreatment did not increase the odds of both clinical pregnancy (OR 0.92, 95% CI [0.70-1.20]), ongoing pregnancy (OR 0.91, 95% CI [0.69-1.19]) and live birth rates (OR 0.84, 95% CI [0.64-1.10]). However, when restricted to women who had no previous transfer attempts, women in the GnRH pretreatment group had lower odds of achieving live birth (OR 0.49, 95% CI [0.30-0.79]). Sensitivity analysis performed in patients with male factor infertility causes showed GnRH agonist pretreated group had lower live birth rates compared to no GnRH agonist pretreatment group (OR = 0.65, 95% CI [0.43-0.97]). Our findings suggested that GnRH agonist pretreatment does not bring additional benefits in live birth rate improvements for ovulatory women undergoing FET cycles. Therefore, the pros of using GnRH agonist to reduce premature ovulation should be weighed against the cons of prolonged time to pregnancy, discomforts resulting from pituitary suppression, and increased medical costs associated with GnRH agonist use.

Developmental potential of different embryos on day 3: a retrospective study

To investigate how different quality of day 3 (D3) embryos affect blastocyst formation and clinical outcomes. This retrospective study analysed 699 patients undergoing assisted reproductive technology (ART) between January 2017 and February 2021. A total of 2517 D3 embryos were transferred to blastocyst medium for extended culture. D3 embryos were divided into five groups. Grade A, 6-10 cells, symmetrical blastomeres and <20% fragmentation; grade B, 6-10 cells, uneven blastomeres and ≥20% fragmentation; grade C, >10 cells, symmetrical blastomeres and <20% fragmentation; grade D, >10 cells, uneven blastomeres and ≥20% fragmentation; grade E, <6 cells. Status of day 5 (D5) and day 6 (D6) blastocysts and the clinical outcomes (blastocyst transfer) of each D3 embryo were recorded. The grade C group showed a higher D5 blastocyst formation rate and a high-quality blastocyst rate than other groups (p<.05). However, the clinical pregnancy rates in the grade A group were higher than other groups (p<.05). Embryos with low speed of development (grade E group) showed considerable clinical outcomes that were still worth investigating. D3 embryos with less fragmentation and ≥6 symmetrical blastomeres revealed a higher developmental potential, while embryos with 6-10 blastomeres showed the ideal clinical outcomes.Impact StatementWhat is already known on this subject? Accurate embryo evaluation can effectively reflect the developmental potential of different embryos. The number of blastomeres, proportion of fragmentation, and blastomere symmetry are three important and popular morphologic parameters used for evaluating day 3 (D3) embryos. However, in existing reports, combining these three parameters for embryo evaluation often results in different results. This is because different researchers have chosen different criteria for these three parameters.What do the results of this study add? In this retrospective study, we summarised the medical records of our reproductive centre in the past three years, redefined the evaluation method of the D3 embryos, and analysed the corresponding developmental potential and clinical outcomes. We conclude that although the embryonic development potential of grade C embryos (>10 cells, symmetrical blastomeres and/or <20% fragmentation) is relatively good, the results of grade A embryos (6-10 cells, symmetrical blastomeres and/or <20% fragmentation) are better in terms of clinical outcomes.What are the implications of these findings for clinical practice and/or further research? We believe this is meaningful for embryologists to choose embryos for transfer and predict the clinical outcome of IVF cycles.

In Vitro Fertilization and Early Pregnancy Outcomes After Coronavirus Disease 2019 (COVID-19) Vaccination

OBJECTIVE

To assess whether coronavirus disease 2019 (COVID-19) mRNA vaccination is associated with controlled ovarian hyperstimulation or early pregnancy outcomes.

METHODS

This retrospective cohort study included patients who underwent controlled ovarian hyperstimulation or single euploid frozen-thawed embryo transfer at a single academic center. Patients fully vaccinated with a COVID-19 mRNA vaccine were compared with unvaccinated patients who cycled during the same time period. The primary outcome was the fertilization rate for controlled ovarian hyperstimulation and the clinical pregnancy rate for frozen-thawed embryo transfer. Secondary outcomes for controlled ovarian hyperstimulation included eggs retrieved, mature oocytes retrieved, mature oocytes ratio, blastulation rate, and euploid rate. Secondary outcomes for frozen-thawed embryo transfer included pregnancy rate, ongoing pregnancy rate, biochemical pregnancy loss rate, and clinical pregnancy loss rate.

RESULTS

Among 222 vaccinated patients and 983 unvaccinated patients who underwent controlled ovarian hyperstimulation cycles between February and September 2021, there was no association on adjusted analysis between COVID-19 vaccination and fertilization rate (β=0.02±0.02, P=.20) or any of the secondary outcomes assessed: eggs retrieved (β=0.01±0.57, P=.99), mature oocytes retrieved (β=0.26±0.47, P=.58), mature oocytes ratio (β=0.02±0.01, P=.12), blastulation rate (β=0.02±0.02, P=.27), or euploid rate (β=0.05±0.03, P=.08). Among 214 vaccinated patients and 733 unvaccinated patients undergoing single euploid frozen-thawed embryo transfer, adjusted analysis demonstrated no significant association between vaccination and clinical pregnancy (adjusted odds ratio [aOR] 0.79, 95% CI 0.54-1.16) or any of the secondary outcomes: pregnancy (aOR 0.88, 95% CI 0.58-1.33), ongoing pregnancy (aOR 0.90, 95% CI 0.61-1.31), biochemical pregnancy loss (aOR 1.21, 95% CI 0.69-2.14), or clinical pregnancy loss (aOR 1.02, 95% CI 0.51-2.06).

CONCLUSION

Administration of COVID-19 mRNA vaccines was not associated with an adverse effect on stimulation or early pregnancy outcomes after IVF. Our findings contribute to the growing body of evidence regarding the safety of COVID-19 vaccination in women who are trying to conceive.

The Impact of the Coronavirus Disease 19 Pandemic on Early Pregnancy Outcomes Among Patients Undergoing In Vitro Fertilization Treatment

Objective: To determine if pregnancy rates (PRs) or pregnancy loss rates (PLRs) were altered in patients undergoing single, euploid frozen-thawed embryo transfer (FET) during the initial peak of the Coronavirus Disease 19 (COVID-19) pandemic.

Materials and Methods: This was a retrospective cohort study performed in a single academic center. Patients undergoing single, euploid FET cycles from January to May 2017–2020 were included. Cycles with FET performed in January–May of 2020 (“COVID-surge cohort”) were compared to cycles with FET performed in January–May of 2017–2019 (“pre-COVID cohort”). Pregnancy rate (PR), clinical pregnancy rate (CPR), pregnancy loss rate (PLR), and clinical pregnancy loss rate (CLR) were compared between the cohorts.

Results: A total of 2629 single, euploid FET cycles were included: 2070 from January to May, 2017–2019 and 559 from January to May 2020. PR was similar when comparing FET performed from January to May 2020 (COVID-surge) to those performed from January to May, 2017–2019 (pre-COVID) (77.6% vs. 73.7%, p = 0.06), while CPR was higher among the COVID-surge compared to the pre-COVID cohort (65.5% vs. 60.0%, p = 0.02). No differences were seen in PLR and CLR among the COVID-surge and pre-COVID cohorts (28.3% vs. 32.0%, p = 0.08; 15.0% vs. 16.5%, p = 0.50). PR, CPR, PLR, and CLR were similar when comparing individual months between the cohorts. Adjusted analysis showed no differences in PR, CPR, PLR, or CLR when comparing the cohorts overall or when comparing corresponding individual months in the two time periods.

Conclusion: PRs and PLRs were not decreased when SARS-CoV-2 transmission was widespread in our geographic area, suggesting that high COVID-19 transmission does not compromise early pregnancy outcomes.

Factors associated with vitrification-warming survival in 6167 euploid blastocysts

PURPOSE

To understand the clinical factors associated with embryo survival after vitrification in a cohort of human blastocysts screened by preimplantation genetic testing for aneuploidy (PGT-A).

METHODS

Patient demographic, embryo, and cycle characteristics associated with failed euploid blastocyst survival were compared in a cohort of women (n = 6167) who underwent IVF-PGT-A.

RESULTS

Compared to those that survived warming, vitrified euploid embryos that failed to survive after warming came from IVF cycles with significantly higher estradiol levels at time of surge (2754.8 ± 1390.2 vs. 2523.1 ± 1190.6 pg/mL, p = 0.03), number of oocytes retrieved (19.6 ± 10.7 vs. 17.5 ± 9.8, p = 0.005), and basal antral follicle count (BAFC) (15.3 ± 8.5 vs. 13.9 ± 7.2, p = 0.05). Euploid embryos were less likely to survive warming if they came from cycles before 2015 (24.6% vs. 13.2%, p < 0.001), were cryopreserved on day 7 versus day 5 or 6 (9.1% vs. 3.0%, p < 0.001), underwent two trophectoderm biopsies (6.9% vs. 2.3%, p < 0.001), had a grade C inner cell mass (15.4% vs. 7.7%, p < 0.001), or were fully hatched (41.1% vs. 12.2%, p < 0.001). In the multivariate model, which controlled for relevant confounders, the association between decreased survival and increased BAFC, year of IVF cycle, double trophectoderm biopsy, and fully hatched blastocysts remained statistically significant.

CONCLUSION

Euploid embryos that are fully hatched at time of vitrification, come from patients with high ovarian reserve, or require repeat trophectoderm biopsy are less likely to survive vitrification-warming. Our results provide a framework for reproductive counseling and offer realistic expectations to patients about the number of embryos needed to achieve family building goals.

Individualised luteal phase support in artificially prepared frozen embryo transfer cycles based on serum progesterone levels: a prospective cohort study

STUDY QUESTION

Does an individualised luteal phase support (iLPS), according to serum progesterone (P4) level the day prior to euploid frozen embryo transfer (FET), improve pregnancy outcomes when started on the day previous to embryo transfer?

SUMMARY ANSWER

Patients with low serum P4 the day prior to euploid FET can benefit from the addition of daily subcutaneous P4 injections (Psc), when started the day prior to FET, and achieve similar reproductive outcomes compared to those with initial adequate P4 levels.

WHAT IS KNOWN ALREADY

The ratio between FET/IVF has spectacularly increased in the last years mainly thanks to the pursuit of an ovarian hyperstimulation syndrome free clinic and the development of preimplantation genetic testing (PGT). There is currently a big concern regarding the endometrial preparation for FET, especially in relation to serum P4 levels around the time of embryo transfer. Several studies have described impaired pregnancy outcomes in those patients with low P4 levels around the time of FET, considering 10 ng/ml as one of the most accepted reference values. To date, no prospective study has been designed to compare the reproductive outcomes between patients with adequate P4 the day previous to euploid FET and those with low, but restored P4 levels on the transfer day after iLPS through daily Psc started on the day previous to FET.

STUDY DESIGN, SIZE, DURATION

A prospective observational study was conducted at a university-affiliated fertility centre between November 2018 and January 2020 in patients undergoing PGT for aneuploidies (PGT-A) IVF cycles and a subsequent FET under hormone replacement treatment (HRT). A total of 574 cycles (453 patients) were analysed: 348 cycles (leading to 342 euploid FET) with adequate P4 on the day previous to FET, and 226 cycles (leading to 220 euploid FET) under iLPS after low P4 on the previous day to FET, but restored P4 levels on the transfer day.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Overall we included 574 HRT FET cycles (453 patients). Standard HRT was used for endometrial preparation. P4 levels were measured the day previous to euploid FET. P4 > 10.6 ng/ml was considered as adequate and euploid FET was performed on the following day (FET Group 1). P4 < 10.6 ng/ml was considered as low, iLPS was added in the form of daily Psc injections, and a new P4 analysis was performed on the following day. FET was only performed on the same day when a restored P4 > 10.6 ng/ml was achieved (98.2% of cases) (FET Group 2).

MAIN RESULTS AND THE ROLE OF CHANCE

Patient's demographics and cycle parameters were comparable between both euploid FET groups (FET Group 1 and FET Group 2) in terms of age, weight, oestradiol and P4 levels and number of embryos transferred. No statistically significant differences were found in terms of clinical pregnancy rate (56.4% vs 59.1%: rate difference (RD) -2.7%, 95% CI [-11.4; 6.0]), ongoing pregnancy rate (49.4% vs 53.6%: RD -4.2%, 95% CI [-13.1; 4.7]) or live birth rate (49.1% vs 52.3%: RD -3.2%, 95% CI [-12; 5.7]). No significant differences were also found according to miscarriage rate (12.4% vs 9.2%: RD 3.2%, 95% CI [-4.3; 10.7]).

LIMITATIONS, REASONS FOR CAUTION

Only iLPS through daily Psc was evaluated. The time for Psc injection was not stated and no serum P4 determinations were performed once the pregnancy was achieved.

WIDER IMPLICATIONS OF THE FINDINGS

Our study provides information regarding an 'opportunity window' for improved ongoing pregnancy rates and miscarriage rates through a daily Psc injection in cases of inadequate P4 levels the day previous to FET (P4 < 10.6 ng/ml) and restored values the day of FET (P4 > 10.6 ng/ml). Only euploid FET under HRT were considered, avoiding one of the main reasons of miscarriage and implantation failure and overcoming confounding factors such as female age, embryo quality or ovarian stimulation protocols.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received. B.C. reports personal fees from MSD, Merck Serono, Ferring Pharmaceuticals, IBSA and Gedeon Richter outside the submitted work. N.P. reports grants and personal fees from MSD, Merck Serono, Ferring Pharmaceuticals, Theramex and Besins International and personal fees from IBSA and Gedeon Richter outside the submitted work. The remaining authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

NCT03740568.

The status of preimplantation genetic testing in the UK and USA

STUDY QUESTION

Has the number of preimplantation genetic testing (PGT) cycles in the UK and USA changed between 2014 and 2016?

SUMMARY ANSWER

From 2014 to 2016, the number of PGT cycles in the UK has remained the same at just under 2% but in the USA has increased from 13% to 27%.

WHAT IS KNOWN ALREADY

PGT was introduced as a treatment option for couples at risk of transmitting a known genetic or chromosomal abnormality to their child. This technology has also been applied as an embryo selection tool in the hope of increasing live birth rates per transfer. ART cycles are monitored in the UK by the Human Fertilisation and Embryology Authority (HFEA) and in the USA by the Society for Assisted Reproductive Technology (SART). Globally, data are monitored via the ESHRE PGT Consortium.

STUDY DESIGN, SIZE, DURATION

This cross-sectional study used the HFEA and SART databases to analyse PGT cycle data and make comparisons with IVF data to examine the success of and changes in patient treatment pathways. Both data sets were analysed from 2014 to 2016. The UK data included 3385 PGT cycles and the USA data included 94 935 PGT cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Following an extensive review of both databases, filters were applied to analyse the data. An assessment of limitations of each database was also undertaken, taking into account data collection by the ESHRE PGT Consortium. In the UK and USA, the publicly available information from these datasets cannot be separated into different indications.

MAIN RESULTS AND THE ROLE OF CHANCE

The proportion of PGT cycles as a total of ART procedures has remained the same in the UK but increased annually in the USA from 13% to 27%. Between 2014 and 2016 inclusive, 3385 PGT cycles have been performed in the UK, resulting in 1074 PGT babies being born. In the USA 94 935 PGT cycles have been performed, resulting in 26 822 babies being born. This gave a success rate per egg collection for PGT of 32% for the UK and 28% for the USA. Analysis of the data by maternal age shows very different patient populations between the UK and USA. These differences may be related to the way PGT is funded in the UK and USA and the lack of HFEA support for PGT for aneuploidy.

LIMITATIONS, REASONS FOR CAUTION

Data reported by the HFEA and SART have different limitations. As undertaken by the ESHRE PGT Consortium, both data sets should separate PGT data by indication. Although the HFEA collects data from all IVF clinics in the UK, SART data only represent 83% of clinics in the USA.

WIDER IMPLICATIONS OF THE FINDINGS

Worldwide, a consistent reporting scheme is required in which success rates can convey the effectiveness of PGT approaches for all indications.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was obtained and there are no competing interests to declare that are directly related to this project. Joyce Harper is the director of the Embryology and PGD Academy, which offers education in these fields.

Utilization of preimplantation genetic testing in the USA

PURPOSE

To evaluate the use of preimplantation genetic testing (PGT) and live birth rates (LBR) in the USA from 2014 to 2017 and to understand how PGT is being used at a clinic and state level.

METHODS

This study accessed SART data for 2014 to 2017 to determine LBR and the CDC for years 2016 and 2017 to identify PGT usage. Primary cycles included only the first embryo transfer within 1 year of an oocyte retrieval; subsequent cycles included transfers occurring after the first transfer or beyond 1 year of oocyte retrieval.

RESULTS

In the SART data, the number of primary PGT cycles showed a significant monotonic annual increase from 18,805 in 2014 to 54,442 in 2017 (P = 0.042) and subsequent PGT cycles in these years increased from 2946 to 14,361 (P = 0.01). There was a significant difference in primary PGT cycle use by age, where younger women had a greater percentage of PGT treatment cycles than older women. In both PGT and non-PGT cycles, the LBR per oocyte retrieval decreased significantly from 2014 to 2017 (P<0001) and younger women had a significantly higher LBR per oocyte retrieval compared to older women (P < 0.001). The CDC data revealed that in 2016, just 53 (11.4%) clinics used PGT for more than 50% of their cycles, which increased to 99 (21.4%) clinics in 2017 (P< 0.001).

CONCLUSIONS

A growing number of US clinics are offering PGT to their patients. These findings support re-evaluation of the application for PGT.

Evaluating in vitro fertilization outcomes of patients with low body mass index following frozen-thawed embryo transfer

OBJECTIVE

To determine the relationship between patients with a low body mass index (BMI; calculated as weight in kilograms divided by the square of height in meters) and in vitro fertilization (IVF) outcomes following frozen-thawed embryo transfer (FET).

METHODS

Retrospective cohort study including 12 618 women aged 20-46 years with an underweight (<18.5) or normal weight (18.5-24.9) BMI who underwent controlled ovarian stimulation for IVF in a private and academic IVF center between August 2002 and December 2019.

RESULTS

Anti-Müllerian hormone, peak estradiol levels, number of MII oocytes, and fertilized oocytes were greater in the underweight group compared with the normal weight group. The total required gonadotropin dose was lower in the underweight patients compared with the normal weight patients. MII, fertilization, blastulation, and euploid rates did not differ before and after adjusting for confounders between BMI groups. In a cohort of 316 patients who underwent preimplantation genetic testing for aneuploidy and single euploid FET, pregnancy loss, pregnancy, clinical pregnancy, and live birth rates before and after controlling for covariates were similar between groups.

CONCLUSION

Although there are known fetal growth or obstetrical issues associated in patients with a low BMI, it is reassuring that these risks do not extend to embryologic or clinical outcomes from IVF treatment.

The freeze-all strategy after IVF: which indications?

The freeze-all strategy is gaining popularity worldwide as an alternative to the conventional fresh embryo transfer. It consists of cryopreservation of the entire embryo cohort and the embryo transfer in a subsequent cycle that takes place separately from ovarian stimulation. The freeze-all strategy was initially a 'rescue' strategy for women at high risk of ovarian hyperstimulation syndrome; however, this approach has been extended to other indications as a scheduled strategy to improve implantation rates. This assumes that ovarian stimulation can alter endometrial receptivity in fresh cycles owing to the effect of supraphysiological levels of steroids on endometrial maturation. The procedure, however, has not been associated with increased live birth rates in all infertile couples, and concerns have been raised about the occurrence of several adverse perinatal outcomes. It is, therefore, crucial to identify in which subgroups of patients a freeze-all strategy could be beneficial. The aim of this review is to summarize current scientific research in this field to highlight potential indications for this strategy and to guide clinicians in their daily practice.

Trophectoderm biopsy for preimplantation genetic test and technical tips: A review

BACKGROUND

Recently, the Japan Society of Obstetrics and Gynecology initiated a clinical study of preimplantation genetic test for aneuploidy. There will be a great need for a standardized embryo biopsy technique in Japan. However, the gold standard trophectoderm (TE) biopsy procedure has not been established, and this review outlines the clinical use of TE biopsy.

METHODS

Based on literature, the method and associated techniques for TE biopsy, a dissection method of TE cells from blastocysts, were investigated.

MAIN FINDINGS

Two TE biopsy methods are used, namely assisted hatching (herniating) and non-assisted hatching (direct suction); however, it is not clear which of these methods is superior. It is critical to understand whether the flicking or pulling method is beneficial.

CONCLUSION

Non-assisted hatching biopsy method may cause blastocyst collapse with a higher probability, and it may extend the biopsy time. The biopsy procedure should be performed within 3 minutes, and thus direct TE suction may have greater disadvantages. It is a fact that pulling method of TE dissection with laser pulse is simple; however, excess laser shots may induce a higher frequency of mosaicism. It is important to understand that each technique of TE biopsy has benefits and disadvantages.

Ovarian response in oocyte donation cycles under LH suppression with GnRH antagonist or desogestrel progestin: retrospective and comparative study

Here are investigated the serum hormones in ovarian stimulation cycles of oocyte donors (OD), under endogenous luteinizing hormone (LH) suppression with GnRH antagonist (antGnRH) vs. desogestrel (DSG) (progesterone-primed [PP]). OD underwent ovarian stimulation with gonadotropins at a private, university-based, infertility center between January 2017 and March 2018. Endogenous LH peak was controlled with either daily injections of antGnRH or with daily oral 75 mcg DSG (PP) until triggering. LH and progesterone were measured at trigger and the following day. A total of 404 OD cycles were included. There were no differences in age (26.7 ± 4.9 vs. 27.1 ± 4.8 years), AMH (3.7 ± 2.1 vs. 4.1 ± 2.7 ng/ml), and body mass index (BMI) (22.4 ± 2.8 vs. 22.1 ± 3.0 kg/m²) between PP and antGnRH groups, respectively. On the day of trigger, progesterone was lower in PP compared to antGnRH (0.9 ± 0.7, vs. 1.5 ± 1.2 ng/ml, p < .001), whereas no significant differences existed in estradiol or LH. On the day after trigger, lower progesterone in PP vs. antGnRH (10.8 ± 6.0 vs. 13.4 ± 7.9 ng/ml, p=.002) was observed. No differences were observed in the number of retrieved oocytes or the clinical pregnancies among recipients. Our study shows that endocrine response to DSG differs significantly as compared to antGnRH use for the control of endogenous LH without apparent impact on number of retrieved oocytes or the clinical pregnancies among recipients.

Clinical outcomes after the transfer of blastocysts characterized as mosaic by high resolution Next Generation Sequencing- further insights

OBJECTIVE

To determine the pregnancy outcome potential of euploid, mosaic and aneuploid embryos.

DESIGN

Retrospective study.

SETTING

Reference genetics laboratories.

PATIENT(S)

2654 PGT-A cycles with euploid characterized embryo transfers, 253 PGT-A cycles with transfer of embryos characterized as mosaic, and 10 PGT-A cycles with fully abnormal embryo transfers.

INTERVENTION(S)

Blastocysts were assessed by trophectoderm (TE) biopsy followed by PGT-A via array CGH or NGS.

MAIN OUTCOME MEASURE(S)

Implantation, miscarriage, ongoing implantation rates (OIR), and karyotype if available, were compared between different embryo groups, and between the two PGT-A techniques.

RESULTS

The Ongoing Pregnancy Rate (OPR)/transfer was significantly higher for NGS-classified euploid embryos (85%) than for aCGH ones (71%) (p < 0.001), but the OPR/cycle was similar (63% vs 59%). NGS-classified mosaic embryos resulted in 37% OPR/cycle (p < 0.001 compared to euploid). Mosaic aneuploid embryos with <40% abnormal cells in the TE sample had an OIR of 50% compared to 27% for mosaics with 40-80% abnormal cells in the TE, and 9% for complex mosaic embryos. All the karyotyped ongoing pregnancies (n = 29) were euploid. Transfers of embryos classified as aneuploid via aCGH (n = 10) led to one chromosomally abnormal pregnancy.

CONCLUSION(S)

NGS-classified euploid embryos yielded higher OIRs but similar OPRs/cycle compared to aCGH. NGS-classified mosaic embryos had reduced potential to reach term, compared to euploid embryos. If they did reach term, those with karyotype results available were euploid. Embryos carrying uniform aneuploidies affecting entire chromosomes were mostly unable to implant after transfer, and the one that implanted ended up in a chromosomally abnormal live birth.

Ultrasonographically diagnosed dermoid cysts do not influence ovarian stimulation response in an in vitro fertilization cycle

To determine if patients with a DC respond similarly to ovarian stimulation when compared to patients without a DC. Infertility patients with a DC that underwent IVF between January 2009 and December 2016 were included. A cystic mass with mixed echogenicity, internal echoes similar to thick bands, fatty-fluid level, or an echogenic tubercle with acoustic shadow (Rokitansky nodule) within two years of the cycle characterized the diagnosis. The z-score compared the standard deviations (SDs) in patients with/without a DC and were compared to a nomogram (expected oocytes minus oocytes obtained divided by the SD), adjusted for age and number of oocytes retrieved, built utilizing cycles from noninfertile female patients. Thirty-nine patients with DC and 7839 patients without DC were identified. The mean number of oocytes (8.6 ± 5.8 vs. 8.5 ± 7.7, p = .43) and MIIs (6.7 ± 4.7 vs. 7.0 ± 6.7, p = .74) retrieved were similar. When cycles with and without a DC were compared to the nomogram (z-score of 0), cycles with a DC presented a z-score for ovarian response of 0.1921 SDs from the mean, and patients without DC presented a z-score of -0.2065 SDs from the mean (similar and less than -1.0). After building a population 'normal' response as a template, patients with and without a DC responded similar to COS.

Endometrial preparation before the transfer of single, vitrified-warmed, euploid blastocysts: does the duration of estradiol treatment influence clinical outcome?

OBJECTIVE

To investigate whether the duration of estrogen administration before euploid embryo transfer affects clinical outcome.

DESIGN

Retrospective cohort study.

SETTING

Private, academic fertility center.

PATIENT(S)

Patients (n = 1,439) undergoing autologous freeze-only in vitro fertilization with preimplantation genetic testing (PGT) followed by endometrial preparation with estrogen and progesterone in a frozen, euploid blastocyst transfer cycle.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Primary outcome was live birth, and secondary outcomes included implantation, clinical pregnancy, early pregnancy loss, live birth, infant birthweight, low birth weight, infant gestational age at delivery, and preterm birth.

RESULT(S)

The duration of estrogen administration (mean: 17.5 ± 2.9 days; range: 10-36 days) before frozen embryo transfer did not impact implantation (odds ratio [OR] 0.99; 95% confidence interval [CI], 0.95-1.03), clinical pregnancy (OR 0.98; 95% CI, 0.94-1.01), early pregnancy loss (OR 1.03; 95% CI, 0.95-1.12), or live birth (OR 0.99; 95% CI, 0.95-1.03). The duration of estrogen exposure did not affect infant birthweight (in grams) (β= -10.65 ± 8.91) or the odds of low birth weight (OR 0.87; 95% CI, 0.68-1.13). For every additional day of estrogen administration, we observed a reduction in gestational age at delivery (in weeks) (β= -0.07 ± 0.03), but the odds of preterm delivery were not affected (OR 1.05; 95% CI, 0.95-1.17).

CONCLUSION(S)

Variation in the duration of estradiol supplementation before progesterone initiation does not impact frozen, euploid blastocyst transfer outcome. The duration of estrogen administration was inversely correlated with gestational age at delivery, but this did not translate into an increase in preterm delivery. Further studies are required on the downstream effects of endometrial preparation on the placental-endometrium interface.

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.

The endometrium during and after ovarian hyperstimulation and the role of segmentation of infertility treatment

Controlled ovarian hyperstimulation (COH) is a crucial part of assisted reproductive technologies (ART) that resulted in a substantial increase in pregnancy rates from in vitro fertilization (IVF). However, in spite of the apparent benefit of COH on an increase in the number of follicles and the number of oocytes retrieved, allowing for extended embryo culture and enabling the selection of the best quality embryo for transfer, several reports has shown that the supraphysiologic hormonal levels may indeed have a detrimental effect at the endometrial level. The current article revises the pathophysiological mechanisms through which ovarian stimulation may negatively affect endometrial receptivity. Also, the evidence is analyzed explaining how segmentation of IVF treatment may allow us to overcome the deleterious effects of hyperstimulation on endometrial receptivity. Deferred embryo transfer may be performed in a more physiologic uterine environment in a subsequent cycle, improve endometrial receptivity, decrease uterine contractility, diminishes the impact of premature luteinization and allow individualized stimulation according to the level of response.

Overcoming the Challenging Cervix: Identification and Techniques to Access the Uterine Cavity

Importance

Cervical stenosis is a challenging clinical entity that requires prompt identification and management in order to avoid iatrogenic injury at the time of endocervical canal cannulation.

Objective

The aim of this study was to identify cervical stenosis and discuss associated etiologies, risk factors, and review medical and surgical approaches for overcoming cervical stenosis.

Evidence Acquisition

Computerized searches of MEDLINE and PubMed were conducted using the key words "cervix", "cervical stenosis," "embryo transfer," "hysteroscopy complications," "misoprostol," and "ultrasound." References from identified sources were manually searched to allow for a thorough review. Data from relevant sources were compiled to create this review.

Results

Transcervical access to the uterine cavity is frequently required for procedures such as hysteroscopy, dilation and curettage, endometrial biopsy, sonohysterogram, hysterosalpingogram, intrauterine insemination, embryo transfer in those undergoing in vitro fertilization, and insertion of intrauterine devices. These procedures can become complicated when difficult cannulation of the endocervical canal is encountered. Management strategies include preprocedural use of cervical-ripening agents or osmotic dilators, ultrasound guidance, no-touch vaginoscopy, manual dilatation, and hysteroscopic resection of the obstructed endocervical canal.

Conclusions and Relevance

Cervical stenosis is associated with iatrogenic complications that can result in significant patient morbidity. In patients undergoing in vitro fertilization, difficult embryo transfer is associated with lower pregnancy rates. The clinician should carefully consider the patient's menopausal status, risk factors, and symptoms in order to anticipate difficult navigation of the endocervical canal. Various medical and surgical management strategies, including hysteroscopic resection, can be used to overcome the stenotic cervix.

Construction of implantation failure related lncRNA-mRNA network and identification of lncRNA biomarkers for predicting endometrial receptivity

Insufficient endometrial receptivity is a major factor leading to implantation failure (IF), and the traditional way of morphological observation of endometrium cannot determine the condition of receptivity sufficiently. Considering that long-noncoding RNAs (lncRNAs) regulate endometrial receptivity and competing endogenous RNA (ceRNA) mechanism works in plenty of biological processes, ceRNA is likely to function in the pathology of IF. In the present study, we aim to construct an implantation failure related lncRNA-mRNA network (IFLMN), and to identify the key lncRNAs as the candidates for predicting endometrial receptivity. The global background network was constructed based on the presumed lncRNA-miRNA and miRNA-mRNA pairs obtained from lncRNASNP and miRTarBase. Differentially expressed genes (DEGs) of IF were calculated using the data of GSE26787, and then re-annotated as differentially expressed mRNAs (DEMs) and lncRNAs (DELs). IFLMN was constructed by hypergeometric test, including 255 lncRNA-mRNA pairs, 10 lncRNAs, and 212 mRNAs. Topological analysis determined the key lncRNAs with the highest centroid. Functional enrichment analyses were performed by unsupervised clustering, GO classification, KEGG pathway, and co-expression module analyses, achieving six key lncRNAs and their ceRNA sub-networks, which were involved in immunological activity, growth factor binding, vascular proliferation, apoptosis, and steroid biosynthesis in uterus and prepared endometrium for embryo implantation. Sixteen endometrial samples were collected during mid-luteal phase, including 8 recurrent implantation failure (RIF) or recurrent miscarriage (RM) women and 8 controls who conceived successfully. Quantitative real-time PCR was performed to compare the expression of the above six lncRNAs, which validated that the expression of all these lncRNAs was significantly elevated in endometrium of RIF/RM patients. Further studies are needed to investigate the underlying mechanism, and the lncRNAs may be developed into predictive biomarkers for endometrial receptivity.

Clinical outcomes of frozen embryo versus fresh embryo transfer following in vitro fertilization: a meta-analysis of randomized controlled trials

PURPOSE

To examine available data from randomized controlled trials to assess if the freeze-all embryo and subsequent frozen-thawed embryo transfer (FET) results in better clinical outcomes than fresh embryo transfer (ET).

METHODS

Meta-analysis.

RESULTS

We conducted an electronic literature search on PubMed and Embase databases and manually supplemented another 2 articles from relevant citations. Seven studies were finally included in the meta-analysis,including 1141 women who underwent fresh embryo transfer and 1079 who underwent frozen embryo transfer. The results of the meta-analysis suggested that the live birth rate [RR (95% CI) 1.18 (1.08-1.30), P = 0.0003] and clinical pregnancy rate [RR (95% CI) 1.10 (1.02-1.19), P = 0.02] were significantly higher in FET group. Miscarriage rate [RR (95% CI) 0.62 (0.48-0.80), P = 0.0002], and moderate to severe OHSS occurrence rate [RR (95% CI) 0.22 (0.12 to 0.39), P < 0.00001] were significantly lower in FET group. Differences of biochemical pregnancy rate, ongoing pregnancy rate and implantation rate between the two groups did not reach the statistical significance.

CONCLUSIONS

Our results suggest that the IVF/ICSI with FET is more efficient and less risky for OHSS compared with ET. However, we should comprehensively inform patients with advantages, disadvantages and potential risks related to embryo cryopreservation, and carefully assess their fertility conditions to make the most beneficial clinical decision.

Frozen blastocyst transfer outcomes in immediate versus delayed subsequent cycles following GnRH agonist or hCG triggers

PURPOSE

The aim of this study is to analyze clinical pregnancy rates (CPR) and ongoing pregnancy rates (OPR) for frozen embryo transfers (FET) performed with blastocysts in the cycle immediately after GnRH agonist (GnRHa) versus human chorionic gonadotropin (hCG) triggers, with outcomes of delayed FET for comparison.

METHODS

Retrospective cohort study at a university-affiliated in vitro fertilization (IVF) clinic, including patients undergoing IVF between 2013-16 with a blastocyst FET performed within two menstrual cycles of a previous stimulation cycle and vaginal oocyte retrieval (VOR). FETs included programmed and natural endometrial preparation. Outcome measures were clinical and ongoing pregnancy rates.

RESULTS

CPR and OPR for 344 FET cycles were similar when comparing immediate and delayed transfer overall (crude CPR 67.5 versus 76.5%, p = 0.11; OPR 57.5 versus 66.7%, p = 0.13), and after stratifying by cycles following hCG trigger (OPR 62.5 versus 66.3%, p = 0.61) and GnRHa trigger (OPR 55.6 versus 64.5%, p = 0.17). When considering a number of predictors for OPR, an adjusted odds ratio (OR) of 1.74 [95% CI 1.00-3.03] approached significance in favor of delayed FET.

CONCLUSIONS

Regardless of trigger modality, patients can be reassured that pregnancy rates with FET are high in immediate and delayed cycles. However, our study suggests a potential benefit in delaying a cycle before proceeding with FET.

The Impact of Vitrification in Artificial Reproductive Technology Programmes

Cryopreservation is an integral part of the current methods of assisted reproductive technology (ART). In the past two decades, slow freezing has been replaced worldwide by vitrification due to its association with improved survival rates and clinical outcomes comparable to fresh embryo transfers. Successful embryo vitrification programmes have led to a significant reduction in the incidences of two major complications of ART: ovarian hyperstimulation syndrome and multiple gestations. Multiple embryo transfer cycles from the single ovum aspiration cycle have had a cumulative effect on the numbers of live births. Oocyte vitrification has also helped women to delay their pregnancies for medical or social reasons. This has made oocyte banking a viable option for better synchronisation of oocyte donation programmes. The emerging field of ovarian tissue vitrification has made fertility preservation possible for women undergoing gonadotoxic therapy. In this review, we have discussed the basic principles and methodology of slow freezing and vitrification along with its need and impact on ART.

Outcomes of IVF cycles coupled with PGS by aCGH of embryos from donor and autologous oocytes, transferred after vitrification to women of advanced maternal age

It is well documented that aneuploidy rate in preimplantation embryos increases with the mother's age, and at the same time the number of oocytes diminishes. Consequently, for patients of advanced maternal age two options are available to overcome these limitations: use of oocytes from young donors, or use of own oocytes coupled with preimplantation genetic screening (PGS) for 24 chromosomes. However, it is not clear which strategy might be more effective. The aim of this retrospective study was to evaluate outcomes of IVF cycles coupled with transfer of vitrified embryos from donor or autologous oocytes, both with or without PGS. Our results demonstrate that while after PGS clinical pregnancy, twin pregnancy and spontaneous abortion rates are similar for embryos from donor and autologous oocytes, these rates are dramatically worse in all cycles without PGS. Therefore, PGS can be recommended as a screening method to all patients of advanced maternal age even when donor oocytes are used.

Detailed investigation into the cytogenetic constitution and pregnancy outcome of replacing mosaic blastocysts detected with the use of high-resolution next-generation sequencing

OBJECTIVE

To determine the pregnancy outcome potential of mosaic embryos, detected by means of preimplantation genetic screening (PGS) with the use of next-generation sequencing (NGS).

DESIGN

Retrospective study.

SETTING

Genetics laboratories.

PATIENT(S)

PGS cycles during which either mosaic or euploid embryos were replaced.

INTERVENTION(S)

Blastocysts were biopsied and processed with the use of NGS, followed by frozen embryo transfer. Trophectoderm (TE) biopsies were classified as mosaic if they had 20%-80% abnormal cells.

MAIN OUTCOME MEASURE(S)

Implantation, miscarriage rates, and ongoing implantation rates (OIRs) were compared between euploid and types of mosaic blastocysts.

RESULT(S)

Complex mosaic embryos had a significantly lower OIR (10%) than aneuploidy mosaic (50%), double aneuploidy mosaic (45%), and segmental mosaic (41%). There was a tendency for mosaics with 40%-80% abnormal cells to have a lower OIR than those with <40% (22% vs. 56%). However, few embryos (n = 34) with a mosaic error in 40%-80% of the TE sample were replaced. There was no difference between monosomic and trisomic mosaics or between entire chromosome mosaicism or segmental mosaicism. Implantation rates were significantly higher (70% vs. 53%), miscarriage rates lower (10% vs. 25%), and OIRs higher (63% vs. 40%) after euploid embryo transfer than after mosaic embryo transfer.

CONCLUSION(S)

Forty-one percent of mosaic embryos produced an ongoing implantation. Complex mosaic blastocysts had a lower OIR than other mosaics. Mosaic monosomies performed as well as mosaic trisomies and mosaic segmental aneuploidies. The results suggest that embryos with >40% abnormal cells and those with multiple mosaic abnormalities (chaotic mosaics) are likely to have lower OIRs and should be given low transfer priority.

Deferred Frozen Embryo Transfer: What Benefits can be Expected from this Strategy in Patients with and without Endometriosis?

Progress with cryopreservation techniques have enabled development of the deferred frozen-thawed embryo transfer (DET) strategy as an alternative to relying on fresh embryo transfers.

With DET, the entire embryo cohort is cryopreserved, and embryo transfer is then performed in a subsequent cycle that takes place separately from the controlled ovarian stimulation (COS).

Initially developed to limit the risk of ovarian hyperstimulation syndrome that occurs with high responders, this strategy has been applied extensively with other populations in an effort to improve implantation rates. The assumption is that COS, which is essential for in vitro fertilization/intra cytoplasmic sperm injection (IVF/ICSI) procedures to obtain a multi-follicular development, could have a detrimental impact on the endometrium as a result of greatly elevated levels of steroids. It is currently not clear whether the DET strategy can be generally applied to all women requiring an IVF/ICSI procedure.

The objectives of this literature review regarding DET, were hence: (i) to present the scientific background that contributed to extensive adoption of this technique, (ii) to detail the pregnancy outcomes and potential obstetric and neonatal consequences, (iii) to report on its ability to prevent risks induced by COS, and (iv) to propose indications for the DET strategy in clinical practice.

Freeze-all cycle for all normal responders?

PURPOSE

The purpose of this study is to evaluate the freeze-all strategy in subgroups of normal responders, to assess whether this strategy is beneficial regardless of ovarian response, and to evaluate the possibility of implementing an individualized embryo transfer (iET) based on ovarian response.

METHODS

This was an observational, cohort study performed in a private IVF center. A total of 938 IVF cycles were included in this study. The patients were submitted to controlled ovarian stimulation (COS) with a gonadotropin-releasing hormone (GnRH) antagonist protocol and a cleavage-stage day 3 embryo transfer. We performed a comparison of outcomes between the fresh embryo transfer (n = 523) and the freeze-all cycles (n = 415). The analysis was performed in two subgroups of patients based on the number of retrieved oocytes: Group 1 (4-9 oocytes) and Group 2 (10-15 oocytes).

RESULT(S)

In Group 1 (4-9 retrieved oocytes), the implantation rates (IR) were 17.9 and 20.5% (P = 0.259) in the fresh and freeze-all group, respectively; the ongoing pregnancy rates (OPR) were 31 and 33% (P = 0.577) in the fresh and freeze-all group, respectively. In Group 2 (10-15 oocytes), the IR were 22.1 and 30.1% (P = 0.028) and the OPR were 34 and 47% (P = 0.021) in the fresh and freeze-all groups, respectively.

CONCLUSION(S)

Although the freeze-all policy may be related to better in vitro fertilization (IVF) outcomes in normal responders, these potential advantages decrease with worsening ovarian response. Patients with poorer ovarian response do not benefit from the freeze-all strategy.

Hatching status before embryo transfer is not correlated with implantation rate in chromosomally screened blastocysts

STUDY QUESTION

Do the reproductive outcomes from the transfer of fully hatched (FH) blastocysts differ from those of not fully hatched (NFH) blastocysts?

SUMMARY ANSWER

Biochemical pregnancy rate (BPR), implantation rate (IR), live birth rate (LBR) and early pregnancy loss (EPL) rate are similar in FH and NFH single euploid blastocyst embryo transfers.

WHAT IS KNOWN ALREADY

The use of extended culture and PGS often leads to transfer of an embryo that is well developed and frequently FH from the zona pellucida. Without the protection of the zona, an FH embryo could be vulnerable to trauma during the transfer procedure. To date, no other study has evaluated the reproductive competence of an FH blastocyst transfer.

STUDY DESIGN, SIZE, DURATION

The retrospective study included 808 patients who underwent 808 cycles performed between September 2013 and July 2015 at a private academic IVF center. Of these, 436 cycles entailed transfer of a NFH blastocyst (n = 123 fresh transfer, n = 313 frozen/thawed embryo transfer (FET)) and 372 cycles entailed transfer of an FH blastocyst (n = 132 fresh, 240 FET). Fresh and FET cycles and associated clinical outcomes were considered separately. LBR was defined as the delivery of a live infant after 24 weeks of gestation.

PARTICIPANTS/MATERIALS, SETTING, METHOD

Trophectoderm biopsies were performed on Day 5 (d5) or 6 (d6) for embryos meeting morphology eligibility criteria (set at ≥3BC). Morphologic grading was determined using a modified Gardner-Schoolcraft scale prior to transfer. A single euploid embryo was selected for transfer per cycle on either the morning of d6, for fresh transfers or 5 days after progesterone supplementation for patients with transfer in an FET cycle. Embryos were classified as NFH (expansion Grade 3, 4 or 5) or FH (expansion Grade 6) cohorts. The main outcome measure was IR.

MAIN RESULTS AND THE ROLE OF CHANCE

In the fresh transfer group, IR was similar between NFH and FH cycles (53.7% versus 55.3%, P = 0.99, odds ratio (OR) 0.9; 95% confidence interval (CI) 0.6-1.5). Secondary outcomes were also statistically similar between groups: BPR (65.9% versus 66.7%, OR 1.0; 95% CI: 0.6-1.6), LBR (43.1% versus 47.7%, P = 0.45, OR 1.2; 95% CI: 0.7-1.9) and EPL rate (22.8% versus 18.2%, OR 1.3; 95% CI: 0.7-2.4). After adjusting for age, BMI, endometrial thickness at the LH surge and oocytes retrieved in a logistic regression (LR) model, the hatching status remained not associated with IR (P > 0.05). In the FET cycles, IR was similar between NFH and FH cycles (62.6% versus 61.7%, OR 1.0; 95% CI: 0.7-1.5). Secondary outcomes were similar between groups: BPR (74.1% versus 72.9%, respectively, OR 1.1; 95% CI: 0.7-1.6), LBR (55.0% versus 50.0%, OR 0.8; 95% CI: 0.6-1.1) and EPL rate (18.9% versus 22.9%, respectively, OR 0.8; 95% CI: 0.5-1.2). After adjusting for age, BMI, endometrial thickness at the LH surge and oocytes retrieved in an LR model, the hatching status was not shown to be associated with implantation (P > 0.05).

LIMITATIONS, REASONS FOR CAUTION

Limitations include the retrospective design and data from a single institution. Additionally, the study was limited to patients that developed high-quality blastocysts suitable for biopsy.

WIDER IMPLICATIONS OF THE FINDINGS

The results suggest that FH embryos are not more fragile or less likely to implant when compared to NFH counterparts. We found no evidence of altered IR or other clinical outcomes in the transfer of FH euploid embryos.

STUDY FUNDING/COMPETING INTERESTS

JG is funded by MSTP grant T32 GM007280 (NIH). No additional funding was received. There are no conflicts of interest to declare..