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To investigate whether endometrial thickness (ET) independently affects the live birth rate (LBR) after embryo transfer. Retrospective study. Private assisted reproductive technology center. A total of 959 single euploid frozen embryo transfers. Vitrified euploid blastocyst transfer. Live birth rate per embryo transfer. The conditional density plots did not demonstrate either a linear relationship between the ET and LBR or a threshold below which the LBR decreased perceivably. Receiver operating characteristic curve analyses did not suggest a predictive value of the ET for the LBR. The area under the curve values were 0.55, 0.54, and 0.54 in the overall, programmed, and natural cycle transfers, respectively. Logistic regression analyses with age, embryo quality, day of trophectoderm biopsy, body mass index, and ET did not suggest an independent effect of the ET on the LBR. We did not identify a threshold of the ET that either precluded live birth or under which the LBR decreases perceivably. Common practice of cancelling embryo transfers when the ET is <7 mm may not be justified. Prospective studies, in which the management of the transfer cycle would not be altered by ET, would provide higher-quality evidence on the subject. [ABSTRACT FROM AUTHOR]

Objective: To present a definition of recurrent implantation failure that accounts for the effects of female age and anticipated blastocyst euploidy rates on cumulative implantation rates.Design: Mathematical modeling.Setting: Not applicable.Patient(s): Not applicable.Intervention(s): Mathematical modeling of cumulative implantation probability on the basis of published blastocyst euploidy rates across categories of female age.Main Outcome Measure(s): The number of blastocysts required to achieve 95% cumulative implantation probability under the assumption of the absence of any other factor affecting implantation.Result(s): When the euploidy status of the transferred embryo is unknown (i.e., not subjected to preimplantation genetic testing for aneuploidies), our simulation shows that no age category reaches 95% cumulative probability of implantation of at least one embryo until after transfer of seven blastocysts. The number of blastocysts required to reach the same threshold is higher for older patients. For example, women older than 38 years require transfer of more than 10 untested blastocysts for the upper range of predictive probability to meet the threshold of 95%. On the other hand, if the implantation rate for a euploid blastocyst is assumed to be 55%, then 4 blastocysts are enough to reach a cumulative probability rate greater than 95%, regardless of age.Conclusion(s): The term "recurrent implantation failure" should be a functional term guiding further management. We suggest that recurrent implantation failure should not be called until implantation failure becomes reasonably likely to be caused by factors other than embryo aneuploidy, the leading cause of implantation failure. We propose a new definition that factors in anticipated blastocyst euploidy rates across categories of female age, euploid blastocyst implantation rate, and a specified threshold of cumulative probability of implantation. [ABSTRACT FROM AUTHOR]

Objective: To evaluate whether endometrioma is associated with a progressive decline in ovarian reserve, and to compare the rate of decline with natural decline in ovarian reserve.Design: Prospective, observational study.Setting: Tertiary university hospital, endometriosis clinic.Patient(s): Forty women with endometrioma and 40 age-matched healthy controls.Intervention(s): Women with endometriomas who did not need hormonal/surgical treatment at the time of recruitment and were expectantly managed. Controls were age-matched, healthy women. All participants underwent serum antimüllerian hormone (AMH) testing twice, 6 months apart. Sexually active patients with endometrioma also underwent antral follicle count.Main Outcome Measure(s): Change in serum AMH levels.Result(s): Median (25th-75th percentile) serum AMH level at recruitment was 2.83 (0.70-4.96) ng/mL in the endometrioma group and 4.42 (2.26-5.57) ng/mL in the control group. The median percent decline in serum AMH level was 26.4% (11.36%-55.41%) in the endometrioma group and 7.4% (-11.98%, 29.33%) in the control groups. Twenty-two women with endometrioma who had antral follicle count (AFC) had median AFC of 10 (8-12) at recruitment and 8 (6.3-10) at 6 months.Conclusion(s): Women with endometrioma experience a progressive decline in serum AMH levels, which is faster than that in healthy women.Clinical Trial Registration Number: NCT02438735. [ABSTRACT FROM AUTHOR]

Objective: To compare complication rates and pain scores after oocyte pickup (OPU) in in vitro maturation (IVM) and IVF cycles. Design: Retrospective cohort study. Setting: University-affiliated ART center. Patient(s): One hundred eighty-eight IVM and 188 IVF OPUs. Intervention(s): IVM OPUs were done using a 19-gauge single-lumen needle, and IVF OPUs were done using a 17-gauge single- or 16-gauge double-lumen needles. Main Outcome Measure(s): Duration of OPU, complication rates, and pain scores during the OPU procedure. Result(s): IVM OPU took significantly more time than IVF OPU (22 vs. 15 minutes). Two women in the IVM and four in the IVF group experienced bleeding from the vaginal wall or ovary. None of them required hospitalization, transfusion, or an operative intervention. One patient in each group had pelvic infection. Severe post-OPU abdominal pain occurred in one patient in the IVM group and five patients in the IVF group. No differences were found between pain scores in the IVF and IVM groups (3.4 vs. 3.8). Conclusion(s): Although IVM OPU requires more punctures per ovary, it is well tolerated and does not seem to be associated with a higher complication rate than IVF OPU. [ABSTRACT FROM AUTHOR]

Objective: To compare complication rates and pain scores after oocyte pickup (OPU) in in vitro maturation (IVM) and IVF cycles. Design: Retrospective cohort study. Setting: University-affiliated ART center. Patient(s): One hundred eighty-eight IVM and 188 IVF OPUs. Intervention(s): IVM OPUs were done using a 19-gauge single-lumen needle, and IVF OPUs were done using a 17-gauge single- or 16-gauge double-lumen needles. Main Outcome Measure(s): Duration of OPU, complication rates, and pain scores during the OPU procedure. Result(s): IVM OPU took significantly more time than IVF OPU (22 vs. 15 minutes). Two women in the IVM and four in the IVF group experienced bleeding from the vaginal wall or ovary. None of them required hospitalization, transfusion, or an operative intervention. One patient in each group had pelvic infection. Severe post-OPU abdominal pain occurred in one patient in the IVM group and five patients in the IVF group. No differences were found between pain scores in the IVF and IVM groups (3.4 vs. 3.8). Conclusion(s): Although IVM OPU requires more punctures per ovary, it is well tolerated and does not seem to be associated with a higher complication rate than IVF OPU. [ABSTRACT FROM AUTHOR]

Objective: To review studies assessing the application of ultrasound automated volume calculation in reproductive medicine. Design: We performed a literature search using the keywords "SonoAVC, sonography-based automated volume calculation, automated ultrasound, 3D ultrasound, antral follicle, follicle volume, follicle monitoring, follicle tracking, in vitro fertilization, controlled ovarian hyperstimulation, embryo volume, embryonic volume, gestational sac, and fetal volume" and conducted the search in PubMed, Medline, EMBASE, and the Cochrane Database of Systematic Reviews. Reference lists of identified reports were manually searched for other relevant publications. Result(s): Automated volume measurements are in very good agreement with actual volumes of the assessed structures or with other validated measurement methods. The technique seems to provide reliable and highly reproducible results under a variety of conditions. Automated measurements take less time than manual measurements. Conclusion(s): Ultrasound automated volume calculation is a promising new technology which is already used in daily practice especially for assisted reproduction. Improvements to the technology will undoubtedly render it more effective and increase its use. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effectiveness and safety of dual renin-angiotensin system (RAS) blockage together with total embryo cryopreservation for prevention of ovarian hyperstimulation syndrome (OHSS) in overstimulated patients undergoing IVF. Design: Retrospective case series. Setting: A private tertiary care hospital assisted reproduction program. Patient(s): Ten women at high risk for OHSS (mean E2 level 9401 ± 585 pg/mL on the day of hCG administration). Intervention(s): Cancellation of ET and dual RAS blockage with an angiotensin receptor blocker (candesartan cilexetil) and an angiotensin-converting enzyme inhibitor (enalapril) starting from day 1 after oocyte retrieval. Embryos were cryopreserved and transferred in subsequent cycles. Main Outcome Measure(s): Development of OHSS and pregnancy and live birth rates after frozen-thawed ETs. Result(s): While eight women did not develop OHSS, two women (20%) developed severe OHSS requiring hospitalization. Subsequent frozen-thawed ETs resulted in an 80% clinical pregnancy rate and 40% live birth rate. Conclusion(s): Dual RAS blockage with total embryo cryopreservation is a relatively new strategy that was proposed for use in patients at high risk for OHSS. It should be stressed that complete elimination of the syndrome is not possible with this treatment. Subsequent pregnancy rates with the transfer of frozen-thawed embryos are high. [Copyright &y& Elsevier]

To date, recurrent implantation failure (RIF) has no clear definition and no clearly identified impaired function. Hence, the term RIF is currently used somewhat haphazardly, on the basis of clinicians' judgment. International experts in reproductive medicine met on July 1, 2022, in Lugano, Switzerland, to review the different facets of RIF and define the diagnosis and its appropriate management. A systematic review without meta-analysis of studies published in English from January 2015 to May 2022. Data indicated that RIF has been largely overevaluated, overdiagnosed, and overtreated without sufficient critical assessment of its true nature. Our analyses show that true RIF is extremely uncommon—occurring in <5% of couples with infertility—and that reassurance and continued conventional therapies are warranted in most cases of assisted reproductive technology (ART) failure. Although the true biologic determinants of RIF may exist in a small subset of people with infertility, they elude the currently available tools for assessment. Without identification of the true underlying etiology(ies), it is reasonable not to assign this diagnosis to a patient until she has failed at least 3 euploid blastocyst transfers (or the equivalent number of unscreened embryo transfers, adjusted to the patient's age and corresponding euploidy rate). In addition, other factors should be ruled out that may contribute to her reduced odds of sustained implantation. In such cases, implantation failure should not be the only issue considered in case of ART failure because this may result from multiple other factors that are not necessarily repetitive or persistent. In reality, RIF impacting the probability of further ART success is a very rare occurrence. True RIF is extremely uncommon, occurring in <5% of couples with infertility. Reassurance and continued conventional therapies are warranted in most cases. It would seem reasonable not to assign this diagnosis to a patient until she has failed at least 3 euploid embryo transfers (or the equivalent number of unscreened embryos, adjusted to her age). Given the number of internationally recognized experts in the field present at the Lugano meeting 2022, our publication constitutes a consensus statement. [ABSTRACT FROM AUTHOR]

Objective: To estimate whether intravenous immunoglobulin (IVIG) improves the probability of a live birth in women with unexplained recurrent miscarriage (RM). Design: A computerized search in Medline, Embase, Central, Ovid Medline In-Process, and Other Non-Indexed Citations Databases and randomized controlled trial (RCT) registries was performed. Abstracts of the American Society of Reproductive Medicine and European Society of Human Reproduction and Embryology annual meetings and reference lists of identified reports were searched. Setting: None. Patient(s): Women with unexplained primary (without a prior live birth) or secondary (subsequent to a live birth) RM. Intervention(s): IVIG or placebo control intervention. Main Outcome Measure(s): Live birth rate per randomized woman. Result(s): Six relevant RCTs were identified including 272 women with unexplained RM. The overall odds ratio for live birth is 0.92, with a 95% confidence interval of 0.55–1.54, indicating a lack of a treatment effect with IVIG. Similarly, IVIG was not found to be beneficial when women with primary and secondary RM were analyzed separately. Conclusion(s): A beneficial effect of IVIG in treatment of RM was not observed. Given the absence of a proven mechanism of action, and the lack of a diagnostic algorithm to identify patients who are likely to benefit from such treatment, IVIG administration for treatment of recurrent miscarriage is not justified outside the context of properly designed RCTs. [Copyright &y& Elsevier]

Objective: To describe a case of moderate ovarian hyperstimulation syndrome (OHSS) that was treated with high dose cabergoline. Design: Case report. Setting: Private assisted reproduction center. Patient(s): A 29-year-old woman who developed early moderate OHSS despite preventive cabergoline administration (0.5 mg/day) following controlled ovarian hyperstimulation for IVF treatment. Intervention(s): Cabergoline dose was increased to 1 mg/day upon diagnosis of OHSS on the second day after oocyte collection and embryo transfer was postponed to the fifth day after oocyte collection. Main Outcome Measure(s): Resolution of OHSS and achievement of healthy live birth. Result(s): OHSS resolved rapidly despite occurrence of pregnancy and patient delivered a healthy boy at term. Conclusion(s): The higher cabergoline dose might have prevented an increase in the severity of OHSS and its prolongation following occurrence of pregnancy. Randomized controlled trials assessing the efficacy and safety of different doses and durations of cabergoline administration in both prophylactic and therapeutic settings are required. [Copyright &y& Elsevier]

Objective: To analyze whether the use of a hyaluronan-enriched transfer medium (HETM) increases rates of implantation (IRs) and clinical pregnancy (CPRs), compared with the use of a conventional transfer medium after day 3 and day 5 embryo transfers. Design: Prospective randomized controlled trial. Setting: An assisted reproduction program in a private tertiary-care hospital in Turkey. Patient(s): A total of 1,282 consecutive fresh embryo transfer cycles (825 day 3 and 457 day 5) were randomly allocated into two groups. In 639 women, ET was effected with HETM, and in 643, it was effected with a conventional embryo transfer medium. Intervention(s): Embryo transfer using HETM or conventional embryo transfer medium. Main Outcome Measure(s): Clinical pregnancy rates and IRs were compared with regard to day of embryo transfer, women''s age, quality of the transferred embryos, and presence of previous implantation failures. Result(s): Overall CPRs and IRs significantly increased with the use of HETM (CPR: 54.6% vs. 48.5%, odds ratio: 1.28, 95% confidence interval: 1.03–1.59; IR: 32% vs. 25%, odds ratio: 1.43, 95% confidence interval: 1.23–1.66, for HETM and control groups, respectively). The number needed to treat (NNT) for one additional pregnancy with routine use of HETM was 17. The beneficial effect was more prominent in women who were >35 years of age (NNT = 7), in women who had previous failed cycles (NNT = 7), and in women who had poor-quality embryos (NNT = 8). Conclusion(s): The enrichment of transfer medium with hyaluronan increases CPRs and IRs, both for day 3 and day 5 embryo transfers. The beneficial effect was most evident in women who were >35 years of age, in women who had only poor-quality embryos available for transfer, and in women who had previous implantation failures. [Copyright &y& Elsevier]

Objective: To investigate the predictive value of endometrial thickness (EMT) for live birth when a lower threshold of EMT is not employed for embryo transfer (ET).Design: Retrospective study SETTING: Academic assisted reproduction center PATIENT(S): All women who underwent fresh or frozen-thawed ET at the Koç University Hospital Assisted Reproduction Unit between October 2016 and August 2019 INTERVENTION(S): After ruling out endometrial pathology, blastocyst transfer was planned regardless of the EMT in the absence of increased serum progesterone level on the trigger day in fresh embryo transfer cycles or before commencing progesterone treatment in artificially prepared frozen-thawed ET cycles.Main Outcome Measure(s): The primary outcome was live birth. Live birth and miscarriage rates per ET were stratified according to fresh and frozen-thawed ET cycles for each millimeter of endometrial thickness. Receiver operator characteristic curve analyses were performed to evaluate the predictive value of EMT for live birth.Result(s): A total of 560 ET cycles, 273 fresh and 287 frozen-thawed, were included in the study. Relevant patient characteristics as well as EMTs were similar between women who achieved a live birth and those who did not after fresh or frozen-thawed ET. There was no linear association between EMT and live birth or miscarriage rates. Area under the curve values for EMT to predict live birth after fresh, frozen-thawed, and all ETs were 0.56, 0.47, and 0.52, respectively.Conclusion(s): Our results showed that the EMT was not predictive for live birth in either fresh or frozen-thawed ET cycles. Once intracavitary pathology and inadvertent progesterone exposure were excluded, women with thinner EMTs should not be denied their potential for live birth because it is comparable to that of those with thicker EMT. [ABSTRACT FROM AUTHOR]

Objective: To determine whether a flexible progestin primed ovarian stimulation (fPPOS) protocol is effective for preventing premature ovulation.Design: Retrospective cohort study.Setting: Private assisted reproduction center.Patient(s): Eighty-seven oocyte donors and 191 recipients of fresh oocytes.Intervention(s): Each donor was stimulated with a flexible gonadotropin-releasing hormone (GnRH) antagonist protocol in one cycle and with the new fPPOS protocol in the other, within a period of 6 months. FSH was started on cycle day 2-3, and 0.25 mg/day GnRH antagonist or 10 mg/day medroxyprogesterone acetate (MPA) was started on stimulation day 7 or when the leading follicle reached 14 mm, whichever came first.Main Outcome Measure(s): Duration of stimulation, gonadotropin consumption, duration of GnRH antagonist or MPA administration, number of metaphase II oocytes, and pregnancy rates in fresh oocyte recipients.Results: Duration of stimulation was 11 (10-11) days in both groups. Total gonadotropin consumption was similar. Pituitary suppression was started on day 7 and lasted for 5 days in each group. There were no premature ovulations in any group. The fPPOS yielded a significantly higher number of cumulus oocyte complexes than GnRH antagonist cycles (33 [21-39] vs. 26 [18-36], respectively). Likewise, the fPPOS generated significantly more metaphase II oocytes than GnRH antagonist cycles (24 [17-34] vs. 21 [15-28], respectively). Recipients of fresh oocytes from fPPOS and GnRH antagonist cycles had similar cleavage, blastulation, implantation, and live birth/ongoing pregnancy rates (50% vs. 48.6%).Conclusion(s): FPPOS with MPA seems to be an effective choice for preventing premature ovulation in women undergoing ovarian stimulation without compromising oocyte quality. [ABSTRACT FROM AUTHOR]

Objective(s): To analyze whether first-degree relatives (FDR) of patients with polysystic ovary syndrome (PCOS) have an increased risk of insulin resistance and glucose intolerance.Design: Systematic review and meta-analysis.Setting: None.Patient(s): Parents and siblings of women with and without PCOS.Intervention(s): Search of PubMed database from 1960 to September 2017 with cross-checking of references of relevant articles in English.Main Outcome Measure(s): Prevalence of type 2 diabetes mellitus (T2DM) and impaired glucose tolerance, and levels of fasting insulin, 2-hour insulin levels, and homeostatic model assessment insulin resistance (HOMA IR).Result(s): Our search retrieved 4,796 articles of which 19 were included. The prevalence of T2DM was significantly increased in mothers and fathers of PCOS probands (rate ratio [RR] 2.43; 95% confidence interval [CI], 1.58-3.75, and RR 2.27; 95% CI, 1.25-4.12). Moreover, the fasting insulin (in mothers, fathers, and sisters) and HOMA IR (in mothers, fathers, and sisters) levels were statistically significantly higher in parents and siblings of PCOS patients. The sisters (RR 1.34; 95% CI, 0.59-3.03) and brothers (RR 1.51; 95% CI, 0.63-3.62) had a higher prevalence of T2DM than the control subjects, but the difference was not statistically significant.Conclusion(s): Our meta-analysis provides quantitative evidence demonstrating clustering of T2DM and insulin resistance in the parents and siblings of PCOS probands.Systematic Review Registration Number: PROSPERO 2016 CRD42016048551. [ABSTRACT FROM AUTHOR]

Objective: To provide an evidence-based assessment of metabolic syndrome, hypertension, and hyperlipidemia in first-degree relatives of women with polycystic ovary syndrome (PCOS).Design: Systematic review and meta-analysis.Setting: Not applicable.Patient(s): Mothers, fathers, sisters, and brothers of women with and without PCOS.Intervention(s): An electronic-based search with the use of PubMed from 1960 to June 2015 and cross-checked references of relevant articles.Main Outcome Measure(s): Metabolic syndrome, hypertension and dyslipidemia, and surrogate markers, including systolic blood pressure (BP), diastolic BP, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides.Result(s): Fourteen of 3,346 studies were included in the meta-analysis. Prevalence of the following was significantly increased in relatives of women with PCOS: metabolic syndrome (risk ratio [RR] 1.78 [95% confidence interval 1.37, 2.30] in mothers, 1.43 [1.12, 1.81] in fathers, and 1.50 [1.12, 2.00] in sisters), hypertension (RR 1.93 [1.58, 2.35] in fathers, 2.92 [1.92, 4.45] in sisters), and dyslipidemia (RR 3.86 [2.54, 5.85] in brothers and 1.29 [1.11, 1.50] in fathers). Moreover, systolic BP (mothers, sisters, and brothers), total cholesterol (mothers and sisters), low-density lipoprotein cholesterol (sisters), and triglycerides (mothers and sisters) were significantly higher in first-degree relatives of PCOS probands than in controls.Conclusion(s): Our results show evidence of clustering for metabolic syndrome, hypertension, and dyslipidemia in mothers, fathers, sisters, and brothers of women with PCOS.Systematic Review Registration Number: PROSPERO 2016 CRD42016048557. [ABSTRACT FROM AUTHOR]

Objective: To compare the clinical outcome of single-embryo transfer (SET) with double-embryo transfer (DET) in in vitro maturation (IVM) cycles performed in patients with polycystic ovary syndrome (PCOS), and to determine which factors predict those outcomes.Design: A retrospective analysis.Setting: Private assisted reproduction center.Patient(s): One hundred and fifty-nine women with PCOS.Intervention(s): In vitro maturation with elective SET or DET conducted between September 2007 and May 2014.Main Outcome Measure(s): Live-birth rates.Result(s): Single-embryo transfer was performed in 83 patients (52.2%), and DET was performed in 76 patients (47.7%). When compared with the patients who had DET, the patients who had SET were statistically significantly younger (32.4 ± 3.5 vs. 24.1 ± 4.2 years) and had a shorter infertility duration (9.2 ± 4.5 vs. 4.4 ± 2.1 years), fewer previous ART cycles (<2 prior attempts, 39.5% vs. 6%; ≥2 prior attempts, 60.5% vs. 0), fewer collected oocytes (15.1 ± 4.6 vs. 12.6 ± 3.8), fewer metaphase II oocytes (9.0 ± 4.1 vs. 5.7 ± 2.9), fewer fertilized oocytes (8.2 ± 3.7 vs. 3.6 ± 2.3), and a higher implantation rate (27% vs. 47%). The SET and DET groups had similar embryo quality and similar clinical pregnancy (44.6% vs. 44.7%) and live-birth rates (34.9% vs. 34.2%). Twin pregnancy rates were statistically significantly higher in the DET compared with the SET groups (9.2% vs. 2.4%).Conclusion(s): In vitro maturation is a successful assisted reproduction technique that can be an alternative to conventional in vitro fertilization in women presenting with PCOS-related infertility. Our observations suggest that SET is a feasible option to prevent multiple pregnancies while maintaining the live-birth rate. [ABSTRACT FROM AUTHOR]

Objective: To determine the extent of intra-age and intercycle variations in the frequency of first polar body aneuploidy in two consecutive cycles of oocyte retrieval undertaken by the same patient within 1 year. Design: Retrospective study. Setting: Fertility centers. Patient(s): Infertile couples undergoing IVF. Intervention(s): Patients underwent two consecutive cycles of preimplantation genetic screening through first polar body biopsy within 1 year. Main Outcome Measure(s): Meiosis I aneuploidy. Result(s): A total of 226 patients underwent 452 cycles of preimplantation genetic screening. Differences within age groups were wide, with 0–100% of oocytes being chromosomally normal in all age groups. Euploidy rates between centers were significantly different (48% vs. 25%). Intercycle differences for the same patient were also wide (0–100%), but with 68.5% of patients having less than ±2 euploid eggs of difference between cycles. Conclusion(s): Although euploidy rate decreased on average with advancing maternal age, the high intra-age and intercenter variation in oocyte chromosome abnormalities emphasize the difficulty in estimating how many euploid oocytes a specific woman will have. This may have repercussions for fertility preservation where a defined number of eggs are currently frozen just based on maternal age. [Copyright &y& Elsevier]

Objective: To compare two commonly used protocols (fresh vs. vitrified) used to transfer euploid blastocysts after IVF with preimplantation genetic screening.Design: Randomized controlled trial.Setting: Private assisted reproduction center.Patient(s): A total of 179 patients undergoing IVF treatment using preimplantation genetic screening.Intervention(s): Patients were randomized at the time of hCG administration to either a freeze-all cycle or a fresh day 6 ET during the stimulated cycle.Main Outcome Measure(s): Implantation rates (sac/embryo transferred), ongoing pregnancy rates (PRs) (beyond 8 weeks), and live birth rate per ET in the primary transfer cycle.Result(s): Implantation rate per embryo transferred showed an improvement in the frozen group compared with the fresh group, but not significantly (75% vs. 67%). The ongoing PR (80% vs. 61%) and live birth rates (77% vs. 59%) were significantly higher in the frozen group compared with the fresh group.Conclusion(s): Either treatment protocol investigated in the present study can be a reasonable option for patients. Freezing all embryos allows for inclusion of all blastocysts in the cohort of embryos available for transfer, which also results in a higher proportion of patients reaching ET. These findings suggest a trend toward favoring the freeze-all option as a preferred transfer strategy when using known euploid embryos.Clinical Trial Registration Number: NCT02000349. [ABSTRACT FROM AUTHOR]