Individual culture leads to decreased blastocyst formation but does not affect pregnancy outcomes in the setting of a single, vitrified-warmed euploid blastocyst transfer.

PURPOSE: To evaluate embryology and pregnancy outcomes following individual and group embryo culture in the setting of contemporary laboratory practices and freeze-all cycles. METHODS: Patients underwent ovarian stimulation followed by intracytoplasmic sperm injection (ICSI). Embryos proceeded through individual culture and then underwent preimplantation genetic testing for aneuploidy (PGT-A) via trophectoderm biopsy. In a subsequent cycle, participants underwent single embryo transfer of a vitrified-warmed, euploid embryo. Outcomes were compared to controls undergoing group culture during the same time frame. The Mann-Whitney U test and logistic regression models were utilized. RESULTS: Outcomes were assessed for 144 patients whose embryos underwent individual culture and 449 controls whose embryos underwent group culture. There were no significant differences in fertilization rates between groups (81.7% for individual culture vs. 84.1% for group culture, p = 0.22). However, individual culture was associated with a decreased rate of blastocyst formation compared to group culture (43.5% vs. 48.5%, p < 0.01). Following single, vitrified-warmed euploid blastocyst transfer, there were no significant differences between individual culture and group culture, respectively, in rates of positive ßhCG (81.9% vs. 81.5%, p = 0.91), sustained implantation (63.9% vs. 65.0%, p = 0.80), biochemical miscarriage (16.7% vs. 12.3%, p = 0.18), or clinical miscarriage (1.4% vs. 4.2%, p = 0.13). CONCLUSION: While individual culture appears to negatively impact the rate of usable blastocyst formation compared to group culture, there were no significant differences in pregnancy outcomes following transfer of a single, vitrified-warmed euploid blastocyst.

Expanded carrier screening in an infertile population: how often is clinical decision making affected?

PURPOSE: Options for preconception genetic screening have grown dramatically. Expanded carrier screening (ECS) now allows for determining carrier status for hundreds of genetic mutations by using a single sample, and some recommend ECS prior to in vitro fertilization. This study seeks to evaluate how often ECS alters clinical management when patients present for infertility care. METHODS: All patients tested with ECS at a single infertility care center from 2011 to 2014 were evaluated. The overall rate of positive ECS results and the number of couples who were carriers of the same genetic disorder were evaluated. RESULTS: A total of 6,643 individuals were tested, representing 3,738 couples; 1,666 (25.1%) of the individuals had a positive test result for at least one disorder. In 8 of the 3,738 couples, both members of the couple were positive for the same genetic disorder or had a test result that placed them at risk of having an affected child. Three of eight cases were cystic fibrosis. In this cohort, ECS affected clinical care eight times after 6,643 tests (0.12%, confidence interval: 0.05-0.24%) in 3,738 couples (0.21%, confidence interval: 0.09-0.42%). CONCLUSIONS: ECS is becoming more widespread. In a large case series, ECS affected clinical decision making for patients presenting for infertility care in 0.21% of cases. This information must be weighed when utilizing these tests and may be a helpful part of patient counseling.Genet Med 18 11, 1097-1101.

FMR1 gene CGG repeat variation within the normal range is not predictive of ovarian response in IVF cycles.

The relationship between FMR1 CGG premutation status and decreased ovarian responsiveness is well established. The association between FMR1 CGG repeat number in the currently defined normal range (less than 45 repeats) and ovarian reserve, however, is controversial. This retrospective study examined whether variation in CGG repeat number in the normal range was associated with markers of ovarian response in IVF cycles. The first IVF cycle of 3006 patients with FMR1 CGG repeat analysis was examined. Only patients carrying two alleles with less than 45 CGG repeats were included for analysis. The CGG repeat number furthest from the modal peak was plotted against number of mature oocytes retrieved and no correlation was identified. Patients were also separated into biallelic genotype groups, based on the recently proposed narrower "new normal" range of 26-34 CGG repeats. A linear regression showed that none of the biallelic genotype groups were associated with a decreased oocyte yield. The euploidy rates after comprehensive chromosomal screening were equivalent among the genotype groups. No difference was found in the rate of cycle cancellation for poor response. Despite increasing use, FMR1 CGG repeats in the normal range cannot be used as a predictor of ovarian response to gonadotrophin stimulation.

Vitamin D levels do not affect IVF outcomes following the transfer of euploid blastocysts.

OBJECTIVE: We sought to characterize the relationship between serum 25-hydroxy vitamin D (25-OH D) levels and implantation and clinical pregnancy rates in women who undergo a euploid blastocyst embryo transfer. STUDY DESIGN: This retrospective cohort study, conducted in an academic setting, included 529 cycles in which comprehensive chromosome screening was performed as part of routine infertility care with an autologous transfer of 1 or 2 euploid blastocysts. After excluding repeat cycles there were 517 unique cycles representing 517 women for evaluation. Vitamin D levels from serum samples obtained on the day of ovulation trigger in the fresh in vitro fertilization cycle were analyzed. The primary outcome was ongoing pregnancy rate as defined by sonographic presence of fetal heart rate at >8 weeks' gestation. RESULTS: For the population as a whole, serum vitamin D ranges and pregnancy outcomes did not correlate. Furthermore, pregnancy rates did not differ when comparing women in different strata of vitamin D levels (<20, 20-29.9, and ≥30 ng/mL). No meaningful breakpoint for vitamin D levels and ongoing pregnancy rate was identified using receiver operating characteristic analysis with the resultant line possessing an area under the curve of 0.502. Multivariate logistic regression controlling for age, transfer order, race, season, and body mass index did not yield a different result. The study was powered to detect an 18% difference in ongoing pregnancy rates between patients grouped by the 3 vitamin D ranges. CONCLUSION: In women undergoing euploid embryo transfer, vitamin D status was unrelated to pregnancy outcomes. Measuring serum 25-OH vitamin D levels does not predict the likelihood that euploid blastocysts will implant. These results may not apply to women who do not undergo extended embryo culture, blastocyst biopsy for comprehensive chromosome screening, and euploid embryo transfer.

Investigating the optimal preconception TSH range for patients undergoing IVF when controlling for embryo quality.

PURPOSE: The ideal thyroid-stimulating hormone (TSH) range for infertile women attempting conception has not been determined. Current recommendations include optimizing the preconception TSH value to ≤2.5 mIU/L, which is the established goal for pregnant women. The aim of this study was to determine if there is a distinct range of TSH ≤2.5 mIU/L for infertile women undergoing in vitro fertilization (IVF) that improves reproductive outcomes. METHODS: One thousand five hundred ninety-nine euploid blastocyst transfer cycles were evaluated in which TSH measurements were obtained 8 days after embryo transfer. Only euploid embryo transfers were included in an effort to control for embryo quality. Patients were separated into TSH groups utilizing 0.5 mIU/L increments. Implantation, live birth, and miscarriage rates among the TSH groups were compared. Outcomes for individuals on thyroid hormone supplementation and those not requiring supplementation were evaluated. RESULTS: There was no difference in implantation (p = 0.56), live birth (p = 0.36), or miscarriage rates (p = 0.10) between TSH groups. Receiver operating characteristic (ROC) curves for implantation, live birth, and miscarriage approached the line of no discrimination, signifying that there is no value of TSH within the recommended range for pregnancy (≤2.5 mIU/L) that predicts IVF outcomes better than other values in this range. Live birth rates for patients requiring thyroid hormone supplementation and those not on medication were similar (p = 0.86). CONCLUSIONS: The recommended TSH range for pregnancy (≤2.5 mIU/L) may be applied to infertile patients attempting conception without a need for further adjustment.

Endometrial disruption does not improve implantation in patients who have failed the transfer of euploid blastocysts.

PURPOSE: To assess the impact of single pass outpatient endometrial biopsy in patients at the highest risk for an endometrial cause for failed implantation; those that have failed to conceive despite the transfer of morphologically normal euploid embryos. METHODS: This is a retrospective cohort study consisting of all patients less than 42 years old who failed their first euploid blastocyst transfer and subsequently completed a second transfer cycle of euploid blastocysts. Cycles were analyzed to determine if a single pass endometrial biopsy, termed 'endometrial disruption', was performed in a cycle preceding their second embryo transfer. Transfer outcomes were analyzed and implantation rates calculated. Data analysis was performed to compare outcomes between patients who had endometrial disruption performed versus those that did not. RESULTS: Two hundred ninety patients failed their first euploid embryo transfer and subsequently completed a second euploid embryo transfer and were included. Thirty-nine patients underwent endometrial disruption and 251 did not. There were no statistical differences in clinical implantation rate or sustained implantation rate between the group with endometrial disruption and subjects without any intervention (Clinical IR, 43.6 % vs. 55.0 %, p = 0.13; 38.5 % vs. 42.6 %, p = 0.60). When controlling for transfer order there was no statistical difference noted in implantation rates. CONCLUSIONS: Single pass endometrial biopsy has no impact on endometrial receptivity in the highest risk subgroup- patient's that have failed to sustain the transfer of morphologically normal euploid embryos- as evidenced by equivalent implantation rates. It is possible that variations in technique may alter outcomes and randomized trials are needed to answer this question.

Obstetrical and neonatal outcomes from the BEST Trial: single embryo transfer with aneuploidy screening improves outcomes after in vitro fertilization without compromising delivery rates.

OBJECTIVE: We sought to determine whether performing elective single embryo transfer (eSET) after trophectoderm biopsy and rapid aneuploidy screening results in improved obstetrical and neonatal outcomes compared with transferring 2 untested embryos. STUDY DESIGN: The Blastocyst Euploid Selective Transfer (BEST) Trial enrolled infertile couples with a female partner up to age 42 years who were undergoing in vitro fertilization. They were randomized to receive transfer of a single euploid embryo (eSET) or to the standard of care with transfer of 2 embryos that were not biopsied for aneuploidy screening (untested 2-embryo transfer). Gestational age at delivery, birthweight, and neonatal intensive care unit (NICU) lengths of stay were compared with Mann-Whitney U. The risk of preterm delivery, low birthweight, and NICU admission were compared with χ(2). RESULTS: Among the 175 randomized patients, the delivery rates were similar (69% after euploid eSET vs 72% after untested 2-embryo transfer; P = .6) through the fresh cycle and up to 1 frozen transfer, with a dramatic difference in multiple births (1.6% vs 47%; P < .0001). The risk of preterm delivery (P = .03), low birthweight (P = .002), and NICU admission (P = .04) were significantly higher after untested 2-embryo transfer. Babies born after untested 2-embryo transfer spent >5 times as many days in the NICU (479 vs 93 days; P = .03). CONCLUSION: By enhancing embryo selection with a validated method of aneuploidy screening, a single euploid embryo with high reproductive potential can be selected for transfer. Using this approach, eSET can be performed without compromising delivery rates and improving the chance of having a healthy, term singleton delivery after in vitro fertilization.

Aneuploidy across individual chromosomes at the embryonic level in trophectoderm biopsies: changes with patient age and chromosome structure.

PURPOSE: To characterize each chromosome's risk for being involved in embryonic aneuploidy. METHODS: This is a retrospective cohort study conducted at a single, academic center. The cohort consisted of 15,169 consecutive trophectoderm biopsies which then underwent comprehensive chromosome screening utilizing validated real-time polymerase chain reaction (RT-PCR) or single nucleotide polymosphism (SNP) array platforms. Analysis was done to determine probability of aneuploidy by chromosome, changes in that risk with increasing maternal age, and in relationship of aneuploidy to chromosomal structure as classified by prior cytogenetic literature. RESULTS: The highest prevalence of imbalances leading to aneuploidy was seen for chromosomes 13, 15, 16, 18, 19, 21, and 22. While elevated in all age groups, there was a disproportionate rise in aneuploidy rates for these chromosomes with increasing maternal age. When classic cytogenetic karyotype groups were compared, the overall smaller groups D, E, and G were associated with the highest rates. Similarly, when grouped based upon structure, acrocentric chromosomes exhibited the highest rates of aneuploidy, followed by the metacentric chromosomes, with the lowest prevalence of error in those with submetacentric structures. CONCLUSIONS: The highest rates of chromosomal aneuploidy were found in chromosomes known to be involved in clinically detectable, abnormal pregnancies, not just simply implantation failure. The rate of aneuploidy in these chromosomes rises disproportionately with age when compared to the other chromosomes which may provide information about chromosomal susceptibility to aging. The biological structure groupings did show varied aneuploidy rates which may provide insight into the biology of aneuploidy.

Embryology training for Reproductive Endocrine fellows in the clinical human embryology laboratory.

OBJECTIVE: To determine if comprehensive embryology training for clinical Reproductive Endocrinology fellows could be completed to a level of proficiency equivalent to that of experienced embryologists. METHOD: Clinical fellows were integrated into the clinical embryology team and were trained to perform all the various procedures utilized in clinical embryology. The fellows were trained to the same standards as the clinical embryology staff and underwent the same certification and sign off procedures. To determine if inclusion of clinical fellows on the embryology team impacted outcomes, outcomes for individual oocytes/embryos and the clinical cases where the fellows perform embryology procedures were compared to the outcomes of those oocytes/embryos and cases performed by the full time embryology staff. RESULTS: Clinical procedures performed by the fellows included isolation and processing of oocytes following retrieval, loading catheters for embryo transfer, and vitrification (N = 823 cases). Micromanipulation procedures compared included ICSI and assisted hatching (N = 650 cases). For each procedure, the outcomes in those cases performed by the RE fellows were equivalent to those done by the fully trained clinical embryology staff. CONCLUSIONS: When fellows are trained to perform embryology procedures as an integral part of their fellowship curricula, laboratory efficiencies and clinical outcomes are fully maintained. This experience provides valuable insight into the ART process critical to this subspecialty. It also empowers fellows to fully participate in research relating to the viability of gamete and embryos and optimization of the clinical ART laboratory.

Trophectoderm DNA fingerprinting by quantitative real-time PCR successfully distinguishes sibling human embryos.

PURPOSE: To validate a novel and more practical system for trophectoderm DNA fingerprinting which reliably distinguishes sibling embryos from each other. METHODS: In this prospective and blinded study two-cell and 5-cell samples from commercially available sibling cell lines and excess DNA from trophectoderm biopsies of sibling human blastocysts were evaluated for accurate assignment of relationship using qPCR-based allelic discrimination from 40 single nucleotide polymorphisms (SNPs) with low allele frequency variation and high heterozygosity. RESULTS: Cell samples with self relationships averaged 95.1 ± 5.9 % similarity. Sibling relationships averaged 57.2 ± 5.9 % similarity for all 40 SNPs, and 40.8 ± 8.2 % similarity for the 25 informative SNPs. Assignment of relationships was accomplished with 100 % accuracy for cell lines and embryos. CONCLUSIONS: These data demonstrate the first trophectoderm qPCR-based DNA fingerprinting technology capable of unequivocal discrimination of sibling human embryos. This methodology will empower research and development of new markers of, and interventions that influence embryonic reproductive potential.

Delivery of a chromosomally normal child from an oocyte with reciprocal aneuploid polar bodies.

PURPOSE: To demonstrate that a euploid embryo derived from an oocyte with reciprocal aneuploid polar bodies is capable of producing a chromosomally normal child. METHODS: A case report of maternal MI error compensation where single nucleotide polymorphism (SNP) microarray based comprehensive chromosome screening (CCS) was performed on the 1st and 2nd polar body, the resulting embryo, and newborn DNA. RESULTS: CCS performed after embryo transfer identified a chromosomally normal embryo that resulted from an oocyte with reciprocal aneuploid polar bodies. The first polar body was found to be missing a single chromatid derived from chromosome 21 and the second polar body possessed an extra chromatid derived from chromosome 21. Compensation of the maternal meiotic error was verified by CCS analysis of a trophectoderm biopsy from the resulting blastocyst which was euploid for all 23 pairs of chromosomes. DNA fingerprinting and CCS of the resulting newborn confirmed a chromosomally normal child, demonstrating the developmental potential of an oocyte with reciprocal aneuploid polar bodies. CONCLUSIONS: This is the first case report demonstrating the reproductive potential of a chromosomally normal embryo derived from an oocyte which had undergone meiosis I error. Systematic investigation into the frequency of meiosis I error compensation and the negative predictive value of polar body aneuploidy screening for reproductive potential should be conducted in order to confirm clinical relevance.

Embryology outcomes after oocyte vitrification with super-cooled slush nitrogen are similar to outcomes with conventional liquid nitrogen: a randomized controlled trial.

OBJECTIVE: To determine whether the use of slush nitrogen (SN), a super-cooled form of nitrogen with a temperature from -207 to -210 °C, can improve oocyte survival after vitrification and warming compared with conventional liquid nitrogen (LN). DESIGN: Randomized controlled trial. SETTING: Academic-affiliated private practice. PATIENT(S): A total of 556 metaphase II oocytes from 32 oocyte donor cycles were included. INTERVENTION(S): Donor oocytes were block randomized to undergo vitrification with either SN or LN. Vitrification was followed by warming, fertilization with donor sperm, embryo culture to the blastocyst stage, and preimplantation genetic testing for aneuploidy via trophectoderm biopsy with targeted next-generation sequencing. MAIN OUTCOME MEASURE(S): The primary outcome was oocyte survival after vitrification and warming. Secondary outcomes included rates of fertilization, usable blastocyst formation, and whole chromosome aneuploidy. RESULT(S): Half of the metaphase II oocytes (n = 278) were randomized to undergo vitrification with SN, whereas the other half (n = 278) were randomized to undergo vitrification with LN. There were no statistically significant differences noted in oocyte survival rate (85.3% vs. 86.3%), fertilization rate (84.0% vs. 80.0%), rate of usable blastocyst formation (54.3% vs. 55.7%), or rate of whole chromosome aneuploidy (9.4% vs. 11.7%) between the SN and LN arms, respectively. CONCLUSION(S): The implementation of an SN oocyte vitrification protocol resulted in similar embryology outcomes compared with LN. The use of SN did not lead to any demonstrable improvement in oocyte survival after vitrification and warming. CLINICAL TRIAL REGISTRATION NUMBER: NCT04342364.

Noninvasive preimplantation genetic testing for aneuploidy exhibits high rates of deoxyribonucleic acid amplification failure and poor correlation with results obtained using trophectoderm biopsy.

OBJECTIVE: To validate a commercially available noninvasive preimplantation genetic testing for aneuploidy (niPGT-A) assay by investigating the following: prevalence of deoxyribonucleic acid (DNA) amplification failure with niPGT-A; factors affecting amplification failure with niPGT-A; and frequency of discordant results between niPGT-A and traditional preimplantation genetic testing for aneuploidy. DESIGN: Prospective cohort study SETTING: Academic-affiliated private practice PATIENT(S): One hundred sixty-six blastocysts and their surrounding culture media from couples undergoing in vitro fertilization between July 2019 and May 2020 were analyzed. INTERVENTION(S): Blastocyst-stage spent culture media samples underwent niPGT-A using a commercially available kit that used whole-genome amplification with a modified multiple annealing and looping-based amplification cycle protocol followed by next-generation sequencing. Preimplantation genetic testing for aneuploidy of trophectoderm (TE) biopsies was performed using targeted next-generation sequencing. MAIN OUTCOME MEASURE(S): The primary outcome was failure to achieve an interpretable result with niPGT-A. Factors affecting DNA amplification were also assessed. Discrepancies between niPGT-A and TE biopsy results were analyzed, and clinical outcomes were evaluated. RESULT(S): Deoxyribonucleic acid amplification failures with niPGT-A were observed in 37.3% (62/166) of the samples. With TE biopsy, no embryos exhibited DNA amplification failure. Embryos with a shorter duration of exposure to the culture media and no evidence of whole-chromosome aneuploidy on the TE biopsy displayed high rates of DNA amplification failure with niPGT-A. Of 104 embryos with both niPGT-A and TE biopsy results available, whole-chromosome discordance was noted in 42 cases (40.4%). Three embryos classified as aneuploid based on the niPGT-A result progressed to successful delivery. CONCLUSION(S): The rates of DNA amplification failure were high among the niPGT-A samples, virtually precluding the clinical applicability of niPGT-A in its current form.

Embryonic aneuploidy rates are equivalent in natural cycles and gonadotropin-stimulated cycles.

OBJECTIVE: To determine if natural selection and follicular stimulation produces a lower risk for embryonic aneuploidy than that attained following superovulation with exogenous gonadotropins. DESIGN: Prospective observational with historical control group. SETTING: Large academically affiliated private practice. PATIENT(S): All patients presenting for their evaluation for infertility were offered participation in the study. INTERVENTION(S): All participants in the natural cycle group underwent an unstimulated in vitro fertilization (IVF) cycle. A subsequent frozen embryo transfer was performed if a euploid blastocyst was attained. MAIN OUTCOME MEASURE(S): Rates of embryonic aneuploidy attained in unstimulated IVF cycles were compared to those observed in age-controlled historical cohort undergoing conventional stimulated IVF cycles with exogenous gonadotropins. RESULT(S): Aneuploidy rates were equivalent in unstimulated and stimulated IVF cycles. The prevalence of aneuploidy in natural cycles increased with the age of the female partner in a manner identical to that seen in stimulated IVF cycles. Finally, sustained implantation rates of euploid blastocysts were equivalent in natural and stimulated IVF cycles. CONCLUSION(S): Rates of embryonic aneuploidy are not impacted by follicular stimulation with exogenous gonadotropins. Prior concerns of inducing a higher risk of embryonic aneuploidy are not supported by this data. CLINICAL TRIAL REGISTRATION NUMBER: NCT01866618.

Investigating the impact of the timing of blastulation on implantation: management of embryo-endometrial synchrony improves outcomes.

STUDY QUESTION: Do embryos with delayed blastulation have inferior reproductive potential or poorer outcomes due in part to embryo and endometrial synchrony? SUMMARY ANSWER: Diminished outcomes in embryos with delayed blastulation undergoing fresh embryo transfer (ET) may be attributed to a loss of embryonic-endometrial synchrony. WHAT IS KNOWN ALREADY: Embryos that blastulate slowly have lower sustained implantation rates (SIR) than those which blastulate normally on Day 5 (D5). Traditionally this has been attributed to reduced embryo quality; however, dyssynchrony with the endometrium is also a possibility and has not been fully described. This convenient cohort composed of groups that resulted from a practice wide change in laboratory protocol allows for evaluation of embryo and endometrial synchrony as it related to blastocyst expansion. STUDY DESIGN SIZE DURATION: A retrospective cohort analysis was carried out from January 2009 to February 2013. Three cohorts were identified: D5 ET, D6 ET and frozen ET that comprised 822 patients, 763 patients and 718 patients, respectively. Each of these cohorts had slowly blastulating and normally blastulating embryos identified. PARTICIPANTS/MATERIALS SETTING METHODS: The study setting was academic affiliated private practice. All first fresh or cryopreserved ETs from 2010 to 2013 were studied. Non-biopsied embryos were classified into two groups on D5: slowly blastulating (Morula-Gardner 1) or normally blastulating (Gardner 2-6). Only single ETs or transfer of two embryos within the same classification group were included. Outcomes were compared between classification groups in embryos undergoing transfer on D5, D6, or after cryopreservation. This assesses the impact of transfer timing in fresh cycles as well as isolating a pure embryonic factor in frozen ET cycles. Sustained implantation was defined as heart beat detection at discharge sonogram at 8 weeks gestation. SIR was defined as the number of embryos transferred meeting criteria for sustained implantation divided by the total number of embryos transferred. MAIN RESULTS AND THE ROLE OF CHANCE: In total, 3391 embryos were transferred to 1966 patients. On D5, SIRs were significantly lower with slowly blastulating embryos (44% versus 64% in women <35 years of age ( P < 0.001) and 18% versus 56% in women ≥35 years of age ( P < 0.001)). Fresh D6 ETs also had significantly lower SIRs for embryos that were slowly blastulating on D5 (52% versus 63% in <35 years of age (P < 0.05) and 32% versus 48% in ≥35 years of age (P < 0.005)) despite continued development to full blastocysts and being morphologically equivalent at the time of ET, suggesting dyssynchrony. However, when slowly blastulating embryos underwent vitrification and then ET, they had SIRs which were equivalent to their normally blastulating counterparts (57% versus 60% in <35 years of age (P = 0.5) and 37% versus 42% in ≥35 years of age (P = 0.3)). An intraclass correlation and a generalized estimating equation corrected for patient age was performed which confirmed these findings. The normalization in cryopreserved ETs indicates that dyssynchrony may be a major adverse factor limiting outcomes with late blastulating embryos in fresh cycles. LIMITATIONS REASONS FOR CAUTION: This is a retrospective study comprising cohorts from a convenient sample chosen due to a uniform change in embryology laboratory protocol regarding ET day, however, this was done independent of the management of embryo and endometrial synchrony. Although strict ultrasound and serum progesterone criteria were utilized to make endometrial receptivity uniform, pathologic states of pre-receptive and post-receptive endometrium cannot be ruled out. WIDER IMPLICATIONS OF THE FINDINGS: The data surrounding embryo and endometrial synchrony should be considered in patients undergoing IVF and attention to the variations in blastulation rates can be applied to any patient undergoing extended embryo culture. STUDY FUNDING/COMPETING INTERESTS: None.

Sequential versus Monophasic Media Impact Trial (SuMMIT): a paired randomized controlled trial comparing a sequential media system to a monophasic medium.

OBJECTIVE: To determine whether sequential or monophasic media is the more optimal formulation for blastocyst development and sustained implantation rates (SIR) in IVF. DESIGN: Paired randomized controlled trials. SETTING: Academic. PATIENT(S): Infertile couples (N = 192) with female partner ≤42 years old and normal ovarian reserve. INTERVENTION(S): Fertilized zygotes from each patient were randomly divided into two groups: [1] cultured in sequential media and [2] cultured in monophasic medium. Sequential media consisted of Quinn's Advantage Cleavage Medium (SAGE) followed by Blast Assist (Origio). The monophasic medium used was Continuous Single Culture (Irvine Scientific). Paired ETs were accomplished by transferring the best euploid blastocyst from each media group. DNA fingerprinting was used to link outcomes. MAIN OUTCOME MEASURE(S): The primary outcome measure was the proportion of blastocysts suitable for clinical use. Secondary outcome measures included timing of blastulation, aneuploidy rates, and SIR. Sustained implantation rate is defined as the number fetal heart beats at 8-9 weeks of gestation, divided by the number of embryos transferred. RESULT(S): A total of 192 patients had their 2PN embryos (N = 2,257) randomized to each culture system. Sequential media had higher blastulation rate than monophasic medium (55.2% vs. 46.9%). No differences were found in the day of blastulation or aneuploidy rate. Of the 168 patients who had euploid blastocysts suitable for transfer, 126 completed a paired ET. Among the double ETs, there was no difference in implantation between groups. CONCLUSION(S): This is the first randomized controlled trial to examine paired euploid transfers of sibling zygotes cultured in sequential versus monophasic media. This study demonstrates that the usable blastocyst rate is greatest after culture in the sequential media tested in comparison with the monophasic formulation selected for study. However, no difference exists in timing of blastulation, aneuploidy, or SIR. Whether these observations are generalizable to other media systems remains to be determined. CLINICAL TRIAL REGISTRATION NUMBER: NCT01917240.

Blastocyst transfer is not associated with increased rates of monozygotic twins when controlling for embryo cohort quality.

OBJECTIVE: To compare monozygotic twinning (MZT) rates in patients undergoing blastocyst or cleavage-stage ET. DESIGN: Retrospective cohort. SETTING: Academic research center. PATIENT(S): Autologous, fresh IVF cycles resulting in a clinical pregnancy from 1999 to 2014. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Monozygotic twin pregnancy in blastocyst-stage transfer vs. cleavage-stage transfer when controlling for patient prognosis and embryo cohort quality factors. RESULT(S): There were a total of 9,969 fresh transfer cycles resulting in a pregnancy during the study period. Of these pregnancies, 234 monozygotic twin pregnancies were identified (2.4%). Of all transfers, 5,191 were cleavage-stage and 4,778 were blastocyst-stage transfers. There were a total of 99 MZT identified in the cleavage-stage group (1.9%) and 135 MZT in the blastocyst ET group (2.4%), which was significant. Multivariable logistic regression revealed that increasing age was associated with a significant reduction in MZT, regardless of transfer order. Embryo cohort quality factors, including the number and proportion of six- to eight-cell embryos and availability of supernumerary embryos, were also significant. When controlling for patient age, time period during which the cycle took place, the number and proportion of six- to eight-cell embryos, and availability of supernumerary embryos, there was no longer a difference in MZT rate between blastocyst and cleavage transfer. CONCLUSION(S): Patient prognosis and embryo cohort quality seem to be major factors in MZT rate in women undergoing blastocyst transfer. Although technology-based effects cannot be excluded, patient and embryo characteristics play an important role.

Examining the temperature of embryo culture in in vitro fertilization: a randomized controlled trial comparing traditional core temperature (37°C) to a more physiologic, cooler temperature (36°C).

OBJECTIVE: To determine whether culture at a more physiologically cooler temperature, as suggested by limited human and animal data, would improve blastulation and pregnancy rates in human clinical IVF. DESIGN: Paired randomized controlled trial. SETTING: Academic. PATIENT(S): Infertile couples (n=52) with a female partner less than 42 years old with eight or more mature oocytes retrieved. INTERVENTION(S): Mature oocytes obtained from a single cohort of oocytes were randomly divided into two groups; one was cultured at 37°C and the other at 36°C from the time of ICSI to the time of embryo transfer or vitrification. Paired embryo transfers were accomplished by transferring one euploid embryo from each group. DNA fingerprinting was used as needed to determine the outcome for each embryo. MAIN OUTCOME MEASURE(S): Rate of development of expanded blastocysts suitable for transfer or vitrification (primary outcome), fertilization, aneuploidy, and sustained implantation. RESULT(S): A total of 805 mature oocytes were cultured; 399 at 36°C and 406 at 37°C. Paired analysis demonstrated a higher rate of usable blastocyst formation per zygote at 37°C (48.4%) vs. at 36°C (41.2%). Rates of fertilization, aneuploidy, and sustained implantation were equivalent. CONCLUSION(S): IVF culture at 36°C does not improve clinically relevant parameters of embryo development or sustained implantation rates. CLINICAL TRIAL REGISTRATION NUMBER: NCT01506089.

The nature of aneuploidy with increasing age of the female partner: a review of 15,169 consecutive trophectoderm biopsies evaluated with comprehensive chromosomal screening.

OBJECTIVE: To determine the relationship between the age of the female partner and the prevalence and nature of human embryonic aneuploidy. DESIGN: Retrospective. SETTING: Academic. PATIENT(S): Trophectoderm biopsies. INTERVENTION(S): Comprehensive chromosomal screening performed on patients with blastocysts available for biopsy. MAIN OUTCOME MEASURE(S): Evaluation of the impact of maternal age on the prevalence of aneuploidy, the probability of having no euploid embryos within a cohort, the complexity of aneuploidy as gauged by the number of aneuploid chromosomes, and the trisomy/monosomy ratio. RESULT(S): Aneuploidy increased predictably after 26 years of age. A slightly increased prevalence was noted at younger ages, with >40% aneuploidy in women 23 years and under. The no euploid embryo rate was lowest (2% to 6%) in women aged 26 to 37, was 33% at age 42, and was 53% at age 44. Among the biopsies with aneuploidy, 64% involved a single chromosome, 20% two chromosomes, and 16% three chromosomes, with the proportion of more complex aneuploidy increasing with age. Finally, the trisomy/monosomy ratio approximated 1 and increased minimally with age. CONCLUSION(S): The lowest risk for embryonic aneuploidy was between ages 26 and 30. Both younger and older age groups had higher rates of aneuploidy and an increased risk for more complex aneuploidies. The overall risk did not measurably change after age 43. Trisomies and monosomies are equally prevalent.

Endometrial infusion of human chorionic gonadotropin at the time of blastocyst embryo transfer does not impact clinical outcomes: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To determine whether endometrial hCG infusion at the time of human blastocyst transfer impacts implantation rates. DESIGN: Randomized double-blinded placebo-controlled trial. SETTING: Academic. PATIENT(S): Infertile couples with the female partner less than 43 years old (n = 300) undergoing fresh or frozen ET of one or two blastocysts. INTERVENTION(S): Patients undergoing ET were randomized into either a treatment or a control group. The treatment group received an infusion of 500 IU of hCG diluted in ET media. The control group received a sham infusion of ET media. Infusions were done using a separate catheter less than 3 minutes before actual ET. MAIN OUTCOME MEASURE(S): Sustained implantation rate: ongoing viable gestation (primary outcome) and ongoing pregnancy rate (secondary outcome). RESULT(S): A total of 473 blastocysts were transferred into 300 patients. There were no differences between the two groups in sustained implantation rate (48.1% in the hCG group, 44.2% in the control group) or ongoing pregnancy rate (58.8% in the hCG group, 52.0% in the control group). CONCLUSION(S): Endometrial infusion of hCG at the time of blastocyst ET does not improve sustained implantation rates. CLINICAL TRIAL REGISTRATION NUMBER: NCT01643993.