Recruiting and cultivating future leaders in laboratory science.

PURPOSE OF REVIEW: Technological in-vitro fertilization (IVF) advancements originate in the embryology laboratory, and are accompanied by increased regulatory oversight and risk management. Stakes have never been higher or the need greater for the recruitment and cultivation of leaders in laboratory science to navigate the direction of IVF. Current thought leaders in state-of-the-art laboratories must prioritize this mission to optimize and preserve the future of IVF. RECENT FINDINGS: Leaders in laboratory science must be able to speak to patients, the lay public, business leaders, scientific colleagues and clinical embryologists. While technically gifted, laboratory leaders may benefit from leadership training. Recruitment of scientists into IVF is currently challenging due to a lack of branding and no clear pipeline for new scientists to enter the field. Once recruited however, cultivation of new leaders requires coaching and skill acquisition over time, in order to create multifaceted laboratory leadership. SUMMARY: Laboratory leaders are typically recruited based on education and experience to lead teams of embryologists. These leaders will adopt new technologies in the laboratory. Therefore, laboratory leaders play a powerful role in IVF requiring leadership skills ultimately driving patient outcomes. These laboratory directors must possess innate leadership abilities or learn how to lead their teams.

Comparing reproductive outcomes between conventional in vitro fertilization and nonindicated intracytoplasmic sperm injection in autologous embryo transfer cycles: a Society for Assisted Reproductive Technology Clinic Outcome Reporting System Study.

Objective: To compare clinical outcomes between nonindicated intracytoplasmic sperm injection (ICSI) and conventional insemination. Design: Autologous cycles performed from 2014-2017 were identified, excluding frozen oocyte cycles. Outcomes were compared between conventional insemination (in vitro fertilization [IVF]) and nonindiated ICSI and analyzed separately for fresh, frozen-thawed preimplantation genetic testing (PGT) and frozen-thawed non-PGT cycles. Setting: US-based fertility clinics reporting to the Society for Assisted Reproductive Technology. Participants: A total of 187,520 patients underwent 318,930 cycles, 57,516 (18.0%) using conventional IVF and 261,414 ICSI (82.0%). Interventions: Intracytoplasmic sperm injection, with or without indications (male factor, prior fertilization failure or any PGT [2012 recommendations]/single-gene PGT [2020 recommendations]). Main Outcome Measures: Odds ratios (ORs) for live birth rates and clinical pregnancy rates were calculated after multivariable adjustment for maternal age, body mass index, infertility etiologies, prior IVF births, and number oocytes retrieved. Results: Intracytoplasmic sperm injection was indicated in 151,627 (58.0%) of cycles according to 2012 American Society for Reproductive Medicine Practice Committee recommendations, and 108,895 (41.7%) according to 2020 recommendations. In multivariable models, nonindicated ICSI among fresh cycles was associated with reduced odds of completing a blastocyst-stage transfer (OR, 0.72; 95% confidence interval [CI] [0.7, 0.75]; P<.001), resulting in reduced odds of live birth (OR, 0.80; 95% CI [0.78, 0.83]; P<.001). Among completed fresh transfers, clinical pregnancy and live birth rates were comparable between nonindicated ICSI and IVF. Nonindicated ICSI in frozen-thawed cycles with PGT and without PGT was associated with comparable live birth and clinical pregnancy rates with IVF in multivariable models. Conclusion: Nonindicated ICSI was associated with reduced blastocyst availability in fresh cycles compared with IVF, leading to lower live birth rates. Outcomes from completed transfers were clinically comparable.

Higher live birth rates are associated with a normal body mass index in preimplantation genetic testing for aneuploidy frozen embryo transfer cycles: a Society for Assisted Reproductive Technology Clinic Outcome Reporting System study.

OBJECTIVE: To determine whether body mass index (BMI) was associated with live birth in patients undergoing transfer of frozen-thawed preimplantation genetic testing for aneuploidy (PGT-A) embryos. DESIGN: Retrospective cohort study of cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System. SUBJECTS: All autologous and donor recipient PGT-A-tested cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System from 2014 to 2017. INTERVENTION(S): Body mass index. MAIN OUTCOME MEASURE(S): The primary outcome measure was the live birth rate, and the secondary outcome measures were the clinical pregnancy and biochemical pregnancy rates. Multivariable generalized additive mixed models and log-binomial models were used to model the relationship between BMI and outcome measures. RESULT(S): A total of 77,018 PGT-A cycles from 55,888 patients were analyzed. Of these cycles, 70,752 were autologous, and 6,266 were donor recipient. In autologous cycles, a statistically significant and clear nonlinear relationship was observed between the BMI and live birth rates, with the highest birth rates observed for the BMI range of 23-24.99 kg/m2. When using 23-24.99 kg/m2 as the referent, other BMI ranges demonstrated a lower probability of live birth and clinical pregnancy that continued to decrease as the BMI moved further from the reference value. Patients with a BMI of <18.5 kg/m2 had a 11% lower probability of live birth, whereas those with a BMI of ≥40 kg/m2 had a 27% lower probability than the referent. CONCLUSION(S): A normal-weight BMI range of 23-24.99 kg/m2 was associated with the highest probability of clinical pregnancy and live birth after a frozen-thawed PGT-A-tested blastocyst transfer in both autologous and donor recipient cycles. A BMI outside the range of 23-24.99 kg/m2 is likely associated with a malfunction in the implantation process, which is presumed to be related to a uterine factor and not an oocyte factor, as both autologous and donor recipient cycle outcomes were associated similarly with the BMI of the intended parent.

Obstetric and Neonatal Outcomes After Transferring More Than One Embryo in Patients With Preimplantation Genetic Testing.

OBJECTIVE: To compare obstetric and neonatal outcomes after single embryo transfer (SET) compared with multiple embryo transfer (MET) from frozen-thawed transfer cycles of embryos that underwent preimplantation genetic testing for aneuploidies (PGT-A). METHODS: We conducted a retrospective cohort study from the SART CORS (Society for Assisted Reproductive Technology Clinic Outcome Reporting System) national database. Clinical and demographic data were obtained from the SART CORS database for all autologous and donor egg frozen-thawed transfer cycles of embryos that underwent PGT-A between 2014 and 2016, after excluding cycles that used frozen oocytes, fresh embryo transfer, and transfers of embryos from more than one stimulation cycle. Multivariable linear and log-binomial regression models were used to estimate the relative and absolute difference in live-birth rate, multiple pregnancy rate, gestational age at delivery, and birth weight between SET compared with MET. RESULTS: In total, 15,638 autologous egg transfer cycles and 944 donor egg transfer cycles were analyzed. Although the live-birth rate was higher with MET compared with SET in the autologous oocyte cycles (64.7% vs 53.2%, relative risk [RR] 1.24, 95% CI, 1.20-1.28), the multiple pregnancy rate was markedly greater (46.2% vs 1.4%, RR 32.56, 95% CI, 26.55-39.92). Donor oocyte cycles showed similar trends with an increased live-birth rate (62.0% vs 49.7%, RR 1.26, 95% CI, 1.11-1.46) and multiple pregnancy rate (54.0% vs 0.8%) seen with MET compared with SET. Preterm delivery rates and rates of low birth weight were significantly higher in MET compared with SET in both autologous and donor oocyte cycles and were also higher in the subanalysis of singleton deliveries that resulted from MET compared with SET. CONCLUSION: Despite some improvement in live-birth rate, nearly half of the pregnancies that resulted from MET of embryos that underwent PGT-A were multiples. Compared with SET, MET is associated with significantly higher rates of neonatal morbidity, including preterm delivery and low birth weight. The transfer of more than one embryo that underwent PGT-A should continue to be strongly discouraged, and patients should be counseled on the significant potential for adverse outcomes.

Remote IVF: a clinical and laboratory guide to performing remote oocyte retrievals.

The aim of this guide is to describe different scenarios when remote IVF would be needed, considerations around how to plan for the procedure, proper equipment in the procedure room, and proper transportation of oocytes from the procedure room. There are two different scenarios for remote IVF: (1) IVF clinics designed knowing the embryology laboratory is nonadjacent and (2) IVF clinics that routinely provide care to patients in their clinic and want to provide care to those who are ineligible for a retrieval under anesthesia in an outpatient facility. This guide will focus on both scenarios. Much of the advice can be used for IVF clinics that routinely perform oocyte retrievals nonadjacent to their embryology laboratories. Special considerations are needed when patients with complex comorbidities require high-level of care and hospital-level monitoring while under anesthesia and/or post-oocyte retrieval, and are thus unable to be treated in the standard facility. For these reasons we have created a comprehensive guide to nonadjacent, or off-site, oocyte retrievals for reproductive endocrinology and infertility (REI) physicians, nurses, and embryologists to use when planning care for IVF patients. Going forward, we will refer to both these scenarios as remote IVF.

The promise and peril of using a large language model to obtain clinical information: ChatGPT performs strongly as a fertility counseling tool with limitations.

OBJECTIVE: To compare the responses of the large language model-based "ChatGPT" to reputable sources when given fertility-related clinical prompts. DESIGN: The "Feb 13" version of ChatGPT by OpenAI was tested against established sources relating to patient-oriented clinical information: 17 "frequently asked questions (FAQs)" about infertility on the Centers for Disease Control (CDC) Website, 2 validated fertility knowledge surveys, the Cardiff Fertility Knowledge Scale and the Fertility and Infertility Treatment Knowledge Score, as well as the American Society for Reproductive Medicine committee opinion "optimizing natural fertility." SETTING: Academic medical center. PATIENT(S): Online AI Chatbot. INTERVENTION(S): Frequently asked questions, survey questions and rephrased summary statements were entered as prompts in the chatbot over a 1-week period in February 2023. MAIN OUTCOME MEASURE(S): For FAQs from CDC: words/response, sentiment analysis polarity and objectivity, total factual statements, rate of statements that were incorrect, referenced a source, or noted the value of consulting providers. FOR FERTILITY KNOWLEDGE SURVEYS: Percentile according to published population data. FOR COMMITTEE OPINION: Whether response to conclusions rephrased as questions identified missing facts. RESULT(S): When administered the CDC's 17 infertility FAQ's, ChatGPT produced responses of similar length (207.8 ChatGPT vs. 181.0 CDC words/response), factual content (8.65 factual statements/response vs. 10.41), sentiment polarity (mean 0.11 vs. 0.11 on a scale of -1 (negative) to 1 (positive)), and subjectivity (mean 0.42 vs. 0.35 on a scale of 0 (objective) to 1 (subjective)). In total, 9 (6.12%) of 147 ChatGPT factual statements were categorized as incorrect, and only 1 (0.68%) statement cited a reference. ChatGPT would have been at the 87th percentile of Bunting's 2013 international cohort for the Cardiff Fertility Knowledge Scale and at the 95th percentile on the basis of Kudesia's 2017 cohort for the Fertility and Infertility Treatment Knowledge Score. ChatGPT reproduced the missing facts for all 7 summary statements from "optimizing natural fertility." CONCLUSION(S): A February 2023 version of "ChatGPT" demonstrates the ability of generative artificial intelligence to produce relevant, meaningful responses to fertility-related clinical queries comparable to established sources. Although performance may improve with medical domain-specific training, limitations such as the inability to reliably cite sources and the unpredictable possibility of fabricated information may limit its clinical use.

The effect of trophectoderm biopsy for preimplantation genetic testing on fetal birth weight and preterm delivery.

BACKGROUND: Preimplantation genetic testing for aneuploidy (PGT-A) is used as part of in-vitro-fertilization (IVF) to assist in selection of euploid embryos, which involves performing trophectoderm biopsy. The effect of possible trauma caused by biopsy and the implication on pregnancy is unknown. Hence, the objective of the study was to determine if embryo biopsy for PGT-A affects birth weight or preterm birth rate. METHODS: Using National Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) data, we identified 6352 cycles which had single embryo transfer (SET) and a singleton live birth following frozen embryo transfer (FET) between 2014 and 2015. RESULTS: From the initial cohort of 25,121 fresh stimulation cycles, 6352 cycles were included who had a singleton live birth following FET. A total of 3482 (54.8%) had PGT-A confirmed euploid embryos and 2870 (45.2%) had embryos selected based on morphology for transfer. No difference in birthweight (g) was noted when FET was performed using PGT-A confirmed euploid embryos as compared to non-tested morphologically selected embryos (3370.7 vs. 3354.5, adjusted regression coefficient 11.4; 95% CI: -12.6; 35.3). As compared to morphologically selected embryos, performance of PGT-A did not increase the risk of small for gestation age (SGA) (3.9% vs. 4.1%, OR: 1.13; 95% CI: 0.86-1.50), low birth weight (LBW) (<2500 g but ≥1500 g) (5.8% vs. 5.5%, OR: 0.90; 95% CI: 0.66-1.21), or very low birthweight (<1500 g) (1.3% vs. 1.0%, OR: 0.44; 95% CI: 0.44 (0.18-1.10). There was no increased risk of preterm birth (PTB) associated with pregnancy resulting from PGT-A embryos vs. non PGT-A embryos (15.8% vs. 16.4%, OR: 0.94; 95% CI: 0.81-1.09). CONCLUSIONS: In our study, trophectoderm biopsy for PGT-A did not increase the risk of SGA, LBW or PTB in IVF pregnancies.

PGT-A is associated with reduced cumulative live birth rate in first reported IVF stimulation cycles age ≤ 40: an analysis of 133,494 autologous cycles reported to SART CORS.

PURPOSE: To evaluate the impact of preimplantation genetic testing for aneuploidy (PGT-A) on cumulative live birth rate (CLBR) in IVF cycles. METHODS: Retrospective cohort study of the SART CORS database, comparing CLBR for patients using autologous oocytes, with or without PGT-A. The first reported autologous ovarian stimulation cycle per patient between January 1, 2014, and December 31, 2015, and all linked embryo transfer cycles between January 1, 2014, and December 31, 2016, were included in the study. Exclusion criteria were donor oocyte cycles, donor embryo cycles, gestational carrier cycles, cycles which included both a fresh embryo transfer (ET) combined with a thawed embryo previously frozen (ET plus FET), or cycles with a fresh ET after PGT-A. RESULTS: A total of 133,494 autologous IVF cycles were analyzed. Amongst patients who had blastocysts available for either ET or PGT-A, including those without transferrable embryos, decreased CLBR was noted in the PGT-A group at all ages, except ages > 40 (p < 0.01). A subgroup analysis of only those patients who had PGT-A and a subsequent FET, excluding those without transferrable embryos, demonstrated a very high CLBR, ranging from 71.2% at age < 35 to 50.2% at age > 42. Rates of multiple gestations, preterm birth, early pregnancy loss, and low birth weight were all greater in the non-PGT-A group. CONCLUSIONS: PGT-A was associated with decreased CLBR amongst all patients who had blastocysts available for ET or PGT-A, except those aged > 40. The negative association of PGT-A use and CLBR per cycle start was especially pronounced at age < 35.

Adherence to embryo transfer guidelines in favorable-prognosis patients aged less than 35 years using autologous oocytes and in recipients using donor oocytes: a Society for Assisted Reproductive Technology Clinic Outcome Reporting System study.

OBJECTIVE: To measure the consequences of nonadherence with the 2013 American Society for Reproductive Medicine elective single embryo transfer (eSET) guidelines for favorable-prognosis patients. DESIGN: Retrospective cohort. SETTING: In vitro fertilization clinics. PATIENT(S): A total of 28,311 fresh autologous, 2,500 frozen-thawed autologous, and 3,534 fresh oocyte-donor in vitro fertilization cycles in 2014-2016 at Society for Assisted Reproductive Technology-reporting centers. INTERVENTION(S): Patients aged <35 years or using donors aged <35 years underwent first blastocyst transfer. MAIN OUTCOME MEASURE(S): Singleton birth rate, gestational age at delivery, and birth weight were compared between the eSET and non-eSET groups using the chi-square or Fisher's exact test or t-tests. RESULT(S): Among fresh transfers, 15,643 (55%) underwent eSET. Live births after non-eSETs were less likely singletons (38.0% vs. 96.5%; adjusted relative risk [aRR], 0.56) and more likely complicated by preterm delivery (55.0% vs. 20.1%; aRR, 2.39) and low birth weight (<2,500 g) (40.1% vs. 10.6%; aRR, 3.4) compared with those after eSET. Among frozen-thawed transfers, 1,439 (58%) underwent eSET. Live births after non-eSETs were less likely singletons (41.9% vs. 95.2%; aRR, 0.69; 95% confidence interval, 0.66-0.73) and more likely complicated by preterm delivery (56.4% vs. 19.5%; aRR, 2.6; 95% confidence interval, 2.2-3.1) and low birth weight (38.0% vs. 8.9%; aRR, 3.9) compared with those after eSET. Among fresh donor oocyte transfers, 1,946 (55%) underwent eSET. Live births after non-eSETs were less likely singletons (31.3% vs. 97.3%; aRR, 0.48) and more likely complicated by preterm delivery (61.1% vs. 25.7%; aRR, 2.09) and low birth weight (44.3% vs. 11.7%; aRR, 3.39) compared with those after eSET. CONCLUSION(S): Nonadherence with transfer guidelines was associated with dramatically increased multiple pregnancies, preterm births, and low birth weights.

The incidence of ectopic/heterotopic pregnancies after blastocyst-stage frozen-thawed embryo transfers compared with that after cleavage-stage: a Society for Assisted Reproductive Technologies Clinical Outcomes Reporting System study.

OBJECTIVE: To investigate whether there is a difference in the ectopic/heterotopic pregnancy rate of blastocyst-stage frozen-thawed embryo transfers (FETs) compared with that of cleavage-stage FETs. DESIGN: A retrospective cohort study. SETTING: Not applicable. PATIENTS: Women undergoing autologous FETs at either the blastocyst stage (n = 118,572) or the cleavage stage (n = 117,619), as reported to the Society for Assisted Reproductive Technology from 2004 to 2013. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Pregnancy outcomes, specifically ectopic pregnancy rates and heterotopic pregnancy rates. RESULTS: Among those who became pregnant, there was a significantly lower incidence of ectopic/heterotopic pregnancies in blastocyst-stage FETs versus that in cleavage-stage FETs (0.8% vs. 1.1%). The differences in ectopic/heterotopic pregnancy rates remained statistically significant after controlling for confounders such as tubal factor infertility and number of embryos transferred. CONCLUSIONS: Blastocyst-stage FET was associated with a lower ectopic/heterotopic pregnancy rate compared with cleavage-stage FET.

The role of preimplantation genetic testing for aneuploidy in a good prognosis IVF population across different age groups.

Preimplantation genetic testing for aneuploidy is associated with increased pregnancy success and reduced miscarriage in women 35 years and older when embryos are available for transfer. In this retrospective cohort study our objective was to evaluate if this holds true in good prognosis patients and across all age groups. Data were obtained from the Society for Assisted Reproductive Technology between 2014-2015. We included only the first single frozen embryo transfer where indication for corresponding 'stimulation/freeze-all cycle' was for reducing risk of ovarian hyperstimulation syndrome and performance of PGT-A for selecting euploid embryos. Our main outcomes were live birth and miscarriage rates. Among <35 age group, no difference in LBR was observed between cycles who underwent single embryo FET using non-PGT-A tested vs. tested embryos (51.7% vs. 50.9%, aOR 1.03, 95% CI 0.87-1.21). Additionally, the miscarriage rates (8.7% vs. 8.8%, aOR 0.97, 95% CI 0.72-1.30) were not different. Among 35-37 years old, no difference was observed between non-PGT-A tested and tested groups in LBR (50.4% vs. 54.7%, aOR 1.26, 95% CI 0.96-1.67) or miscarriage rates (8.3% vs. 10%; aOR 1.11, 95% CI 0.68-1.82). Similarly, among > 37 year old, no difference was observed between non-PGT-A tested and tested groups in LBR (48.1% vs. 53.2%, aOR 1.27, 95% CI 0.8-2.02) and miscarriage rates (6.2% vs. 8.5%, aOR1.34, 95% CI 0.52-3.43). To conclude, PGT-A tested embryos did not improve LBR and miscarriage rates in a good prognosis IVF population across all age groups.Abbreviations: PGT-A: preimplantation genetic testing for aneuploidy; FET: frozen embryo transfer; LBR: live birth rate; OHSS: ovarian hyperstimulation syndrome; SART: society for assisted reproductive technology.

Increased male live-birth rates after blastocyst-stage frozen-thawed embryo transfers compared with cleavage-stage frozen-thawed embryo transfers: a SART registry study.

OBJECTIVE: To investigate whether there is a difference in live-birth gender rates in blastocyst-stage frozen-thawed embryo transfers (FETs) compared with those in cleavage-stage FETs. DESIGN: Retrospective cohort study. SETTING: Academic medical center. PATIENTS: All women with recorded live births who underwent FET at either the blastocyst or cleavage stage, reported to the Society for Assisted Reproductive Technology during 2004-2013. INTERVENTIONS: None. MAIN OUTCOME MEASURES: The primary outcome was live-birth gender rates. Demographic criteria were also collected. The chi-square analyses were used for bivariate associations, and multiple logistic regression models were used for adjusted associations, with all two-sided P<.05 considered statistically significant. RESULTS: A statistically significant increase was noted in the number of live male births after blastocyst-stage FET compared with that after cleavage-stage FET (51.9% vs. 50.5%). After controlling for potential confounders including age (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.03, 1.08), body mass index (OR, 1.08; 95% CI, 1.04, 1.12), and male factor infertility (OR, 1.06; 95% CI, 1.03, 1.08), the increase in male live births after blastocyst-stage FET remained statistically significant. CONCLUSIONS: In patients undergoing FETs, blastocyst-stage transfers are associated with higher male gender live-birth rates compared with cleavage-stage transfers.

Early experience with universal SARS-CoV-2 testing in a New York-based reproductive endocrinology practice.

The SARS-CoV-2 pandemic peak around March 2020 led to temporary closures of most fertility clinics. Many clinics reopened but required universal SARS-CoV-2 screening. However, the rate of positive results and the necessity for such testing is unknown. We report here on early results from asingle-center academic NewYork fertility practice utilizing universal SARS-CoV-2 screening. This mixed prospective retrospective cohort included 164 patients who underwent at least one SARS-CoV-2 screening test for fertility treatment between May and July2020. Patients completed 1 to 3 nasopharyngeal SARS-CoV-2 tests per cycle and remained symptom-free to continue fertility treatments. SARS-CoV-2 test results, past results, history of Covid-19 infection, and patient/cycle characteristics were recorded and tabulated through October2020. Outcomes included positive SARS-CoV-2 RNA tests, rate of prior Covid-19 infections, and clinical courses of patients testing positive. Patients underwent 263 cycles entailing 460 total SARS-CoV-2 screening tests. Fifteen patients reported astrong prior clinical history of Covid-19. Six patients experienced apositive SARS-CoV-2 test (2.3% of all cycles). Among 77 cycles (n = 58 patients) entailing one SARS-CoV-2 test, 2 cases (2.6%) were noted. Among 173 cycles (n = 121 patients) entailing two SARS-CoV-2 tests, 4 cycles (2.3%) were noted. Zero (0%) of 13 cycles (n = 13 patients) entailing 3 SARS-CoV-2 tests were positive. All patients were cleared to resume treatment within one month. Overall, anew asymptomatic infection was identified in 2 cycles (0.8%), while 4 of the 6 positive SARS-CoV-2 tests were among patients with aprior history of Covid-19. 3 of 4 also had adocumented prior positive RNA test. Our data suggest that universal SARS-CoV-2 screening among fertility patients is feasible, with an approximately 2% positive rate per cycle among the patients of this study. Most positive patients had aprior remote infection, but their infectiousness while being screened remains unclear.Abbreviations: REI: reproductive endocrinology and infertility; IUI: intrauterine insemination; IVF: in vitro fertilization; sono: sonography; cryo: cryopreservation; FET: frozen embryo transfer.

A workflow for simultaneous DNA copy number and methylome analysis of inner cell mass and trophectoderm cells from human blastocysts.

OBJECTIVE: To establish a workflow for isolating single trophectoderm (TE) and inner cell mass (ICM) cells and to simultaneously evaluate these cells for copy number variation (CNV) as well as methylome development. DESIGN: Experimental. SETTING: Academic medical center. PATIENT(S): Donated genetically abnormal blastocysts. INTERVENTION(S): Single cells were isolated, followed by bisulfite conversion and sequencing to identify CNV and methylome profiles. MAIN OUTCOME MEASURE(S): CNV and methylation profiling. RESULT(S): Two embryos were dissociated, isolating 46 single cells, with 17 ICM and 12 TE cells selected for further downstream analysis. Chromosome ploidies and embryo sex were concordant with the results from conventional aneuploidy testing. In 3 of the 29 cells, additional aneuploidies were discovered, indicating possible mosaicism undetected by routine preimplantation genetic testing for aneuploidy. CpG methylation frequency was higher in ICM cells compared with TE cells (44.3% vs. 32.4%), respectively, while non-CpG methylation frequency was similar among both cell types. CpG methylation levels accurately distinguished ICM from TE cells epigenetically. CONCLUSION(S): We describe an effective workflow for isolating and sequencing single ICM and TE cells from human blastocysts. The use of methylation profiling can help distinguish these two cell populations better then morphologic identification alone. TE cells had significantly lower levels of DNA methylation, which may be explained in part by the fact that these cells have begun the process of differentiation and are transcriptionally more active than ICM. This approach may be used to explore the genetic complexities within human embryos, specifically among the two primary cell types seen at this stage of development.

Differential impact of controlled ovarian hyperstimulation on live birth rate in fresh versus frozen embryo transfer cycles: a Society for Assisted Reproductive Technology Clinic Outcome System study.

OBJECTIVE: To study the impact of both controlled ovarian hyperstimulation (COH) length and total gonadotropin (GN) dose individually and in concert on live birth rates (LBR) in both fresh and freeze-all in vitro fertilization embryo transfer (IVF-ET) cycles. DESIGN: Historical cohort study. SETTING: Not applicable. PATIENT(S): The U.S. national database from the Society of Assisted Reproductive Technology Clinic Outcome Reporting System from 2014 to 2015 was used to identify patients undergoing autologous GN stimulation IVF cycles with the use of GnRH antagonist-based suppression protocols where a single embryo transfer was performed as part of a fresh IVF-ET cycle (fresh, n = 14,866) or the first frozen embryo transfer after a freeze-all cycle (frozen, n = 2,964), and not including preimplantation genetic testing cycles. The patients' demographic and cycle characteristics, duration of COH, total GN dose, and pregnancy outcomes were extracted. Binomial regression models estimated trend and relative risk of live birth with respect to days of stimulation and total GN dose singularly, and after adjustment for a priori confounders including age, parity, body mass index, diagnosis, and maximum follicle-stimulating hormone in both fresh and frozen embryo transfer cycles. Both days of stimulation and total GN dose were then added to the multivariate model to show whether they were independently associated with LBR. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Live birth rate. RESULTS: In both fresh and frozen cycles, length of COH was significantly associated with total GN dose. On univariate analysis, LBR decreased significantly with increasing length of stimulation and increasing total GN dose in both fresh and frozen cycles. On multivariable analysis including both days of stimulation and total GN dose, days of stimulation was no longer significantly correlated with LBR, whereas total GN dose remained significantly correlated with LBR in fresh cycles only. When total GN doses ranging from <2,000 IU through 5,000 IU to >5,000 IU were compared, a significant improvement in live birth rate was noted with lower total GN doses. Specifically, GN doses <2,000 IU had a 27% higher rate of live birth compared with GN dose >5,000 IU. For GN dose groups up to 4,000 IU, the estimated effect on LBR was similar. There was a marginal improvement (13%) in LBR with GN doses of 4,000 IU to 5,000 IU compared with >5,000 IU. When the multivariate model was applied to the frozen cycles, neither total GN dose nor days of stimulation was significantly associated with LBR. CONCLUSIONS: High total GN dose but not prolonged COH is associated with decreasing LBRs in fresh cycles, whereas neither factor significantly affects LBR in frozen cycles. Consideration should be given to minimizing the total GN dose when possible in fresh autologous cycles, either by decreasing the daily dose or by limiting the length of stimulation to improve LBRs. In freeze-all cycles, the use of higher GN doses does not seem to adversely affect the LBR of the first frozen embryo transfer. High total GN dose likely exerts a negative impact on the endometrium and/or oocyte/embryo unrelated to the length of stimulation. The differential effect of total GN dose on LBR in fresh and frozen cycles may imply a greater impact exerted on the endometrium rather than the oocyte.