Attitudes, concerns, and perceptions of patients undergoing fertility treatments in an abortion restrictive state in the aftermath of the Roe v. Wade reversal.

PURPOSE: To investigate the abortion views and reproductive concerns of current in vitro fertilization patients after the US Supreme Court Dobbs v. Jackson decision, which overturned the Roe v. Wade decision guaranteeing abortion access. METHODS: This is a cross-sectional survey of English-speaking patients undergoing in vitro fertilization from January to November 2022 at a large academic institution in a state with restricted abortion care. Participants completed a 43-question electronic survey which measured feelings about abortion, future fertility treatments, and embryo disposition both quantitatively and qualitatively. RESULTS: Of 543 eligible patients, 267 (49%) consented to participate when called and were sent the survey. Of those, 180 (67%) completed it, resulting in a total completion rate of 33%. The majority believe abortion should be legal in the case of birth defects (90.8%) or rape or incest (90.3%). A significant proportion (91.4%) expressed concerns about abortion being illegal in the state that they receive infertility care. They reported some concern about making embryos (89.6%), controlling what happens to them (95.4%), and discarding them (94.4%). Patients wrote about their concerns with pursuing fertility treatments, fear of not having access to needed medical care, and the desire to remain close to states with less restrictive abortion laws. CONCLUSIONS: The evolving political landscape surrounding access to reproductive care has created significant concerns regarding legal regulation of these treatments and the disposition of embryos. By understanding patients' concerns, health care providers can more effectively advocate for the protection of fertility treatments and patients' autonomy in embryo disposition.

Websites about, not for, adolescents? A systematic analysis of online fertility preservation information for adolescent and young adult cancer patients.

PURPOSE: Fertility preservation is an increasingly important topic in adolescent and young adult cancer survivorship, yet treatments remain under-utilized, possibly due to lack of awareness and understanding. The internet is widely used by adolescents and young adults and has been proposed to fill knowledge gaps and advance high-quality, more equitable care. As a first step, this study analyzed the quality of current fertility preservation resources online and identified opportunities for improvement. METHODS: We conducted a systematic analysis of 500 websites to assess the quality, readability, and desirability of website features, and the inclusion of clinically relevant topics. RESULTS: The majority of the 68 eligible websites were low quality, written at college reading levels, and included few features that younger patients find desirable. Websites mentioned more common fertility preservation treatments than promising experimental treatments, and could be improved with cost information, socioemotional impacts, and other equity-related fertility topics. CONCLUSIONS: Currently, the majority of fertility preservation websites are about, but not for, adolescent and young adult patients. High-quality educational websites are needed that address outcomes that matter to teens and young adults, with a priority on solutions that prioritize equity. IMPLICATIONS FOR CANCER SURVIVORS: Adolescent and young adult survivors have limited access to high-quality fertility preservation websites that are designed for their needs. There is a need for the development of fertility preservation websites that are clinically comprehensive, written at appropriate reading levels, inclusive, and desirable. We include specific recommendations that future researchers can use to develop websites that could better address AYA populations and improve the fertility preservation decision making process.

Websites about, not for, adolescents? A systematic analysis of online fertility preservation information for adolescent and young adult cancer patients.

Purpose Fertility preservation is an increasingly important topic in adolescent and young adult cancer survivorship, yet treatments remain under-utilized, possibly due to lack of awareness and understanding. The internet is widely used by adolescents and young adults and has been proposed to fill knowledge gaps and advance high-quality, more equitable care. As a first step, this study analyzed the quality of current fertility preservation resources online and identified opportunities for improvement. Methods We conducted a systematic analysis of 500 websites to assess the quality, readability, and desirability of website features, and the inclusion of clinically relevant topics. Results The majority of the 68 eligible websites were low quality, written at college reading levels, and included few features that younger patients find desirable. Websites mentioned more common fertility preservation treatments than promising experimental treatments, and could be improved with cost information, socioemotional impacts, and other equity-related fertility topics. Conclusions Currently, the majority of fertility preservation websites are about, but not for, adolescent and young adult patients. High-quality educational websites are needed that address outcomes that matter to teens and young adults, with a priority on solutions that prioritize equity. Implications for Cancer Survivors: Adolescent and young adult survivors have limited access to high-quality fertility preservation websites that are designed for their needs. There is a need for the development of fertility preservation websites that are clinically comprehensive, written at appropriate reading levels, inclusive, and desirable. We include specific recommendations that future researchers can use to develop websites that could better address AYA populations and improve the fertility preservation decision making process.

Evaluating the utility of a global webinar for mentoring medical students and OBGYN residents in REI.

BACKGROUND: In medical school and residency, clinical experiences influence trainee's decisions on what medical specialty they choose. Most trainees have limited access to opportunities to engage in the field of reproductive endocrinology and infertility (REI). Due to the COVID-19 pandemic and the shutdown of away electives, exposure to REI was especially limited. This study aims to evaluate the effectiveness of a live Q and A webinar on improving trainees' access to mentorship and knowledge of the path to becoming a reproductive endocrinology and infertility (REI) physician. MATERIALS AND METHODS: This study is a prospective paired cohort study. Medical students and OBGYN residents participated in a global Q and A webinar featuring REI physicians and fellows. 70 pre- and post-webinar surveys were included in the analysis. Paired nonparametric tests (Wilcoxon signed-rank test) were performed to assess whether post-webinar knowledge was significantly different from pre-webinar knowledge. RESULTS: Of the 268 registrants, 162 (60%) attended the live webinar. A majority of the respondents who completed both surveys were female (90%) and allopathic medical students (80%). Seventy-seven percent reported receiving only minimal advice about an REI career from their medical school or residency program, while 22% reported receiving some advice, and 1% extensive advice. Thirty-four percent had previously shadowed an REI physician and 23% had rotated in an REI office. Post-webinar significantly more trainees had a better understanding of the REI field, the path required to become an REI physician, opportunities to find mentors in the field, opportunities that are conducive to learning more about REI, and applying for rotations in the REI field (p = <.00001). Eighty-two percent agreed that their interest in REI increased due to this webinar. CONCLUSIONS: A webinar featuring REI physicians and fellows was effective in providing mentorship and career advisement for prospective REI trainees who otherwise expressed having limited access to the field.

Diverse monogenic subforms of human spermatogenic failure.

Non-obstructive azoospermia (NOA) is the most severe form of male infertility and typically incurable. Defining the genetic basis of NOA has proven challenging, and the most advanced classification of NOA subforms is not based on genetics, but simple description of testis histology. In this study, we exome-sequenced over 1000 clinically diagnosed NOA cases and identified a plausible recessive Mendelian cause in 20%. We find further support for 21 genes in a 2-stage burden test with 2072 cases and 11,587 fertile controls. The disrupted genes are primarily on the autosomes, enriched for undescribed human "knockouts", and, for the most part, have yet to be linked to a Mendelian trait. Integration with single-cell RNA sequencing data shows that azoospermia genes can be grouped into molecular subforms with synchronized expression patterns, and analogs of these subforms exist in mice. This analysis framework identifies groups of genes with known roles in spermatogenesis but also reveals unrecognized subforms, such as a set of genes expressed across mitotic divisions of differentiating spermatogonia. Our findings highlight NOA as an understudied Mendelian disorder and provide a conceptual structure for organizing the complex genetics of male infertility, which may provide a rational basis for disease classification.

Satisfaction with new patient telehealth visits for reproductive endocrinology patients in the era of COVID-19.

PURPOSE: To study patient satisfaction with new patient telehealth visits in a reproductive endocrinology and infertility (REI) office. METHODS: A cross-sectional study in a university-based fertility clinic was completed including all new patients seen via telehealth between March 1, 2021, and August 19, 2021. Primary outcomes were perceived patient satisfaction, access, and preferences to telehealth visits. RESULTS: A total of 351 participants were contacted, 61.8% (n = 217) agreed to participate in the study, and 28.8% (n = 101) completed the survey. There were no significant differences in age, BMI, distance from clinic, or length of infertility with response to survey. Ninety-three percent of responders would use telehealth services again and were satisfied with the telehealth system. Telehealth improved access to healthcare for 88% and travel time for 96%. The median distance from clinic was 24 miles, and there was no significance difference in preference for telehealth visits over in person visits (p = 0.696). CONCLUSIONS: In the era of COVID-19, healthcare implementation has dramatically changed with a drastic increase in telehealth services. Based on our survey, majority of patients were satisfied with telehealth visits and believed it saved travel time while improving access to REI care. Despite no differences in patient preference for in person versus telehealth depending on their distance from clinic, this is reassuring because patients are satisfied with telehealth for reasons other than distance from clinic.

Innovative Social Media Summit: Providing a Path for Physicians on Social Media.

PROBLEM: Physicians' voices are valued in society and should be present in mainstream social media where they can provide valuable public health messaging and patient education as well as increase opportunities for medical education, mentoring, and collaboration. However, lack of formal education on effective use of social media prevents many physicians from using it. APPROACH: The authors developed a physician-led social media training program to address the need for formal instruction on social media use. The program was presented to medical students, trainees, and faculty at an academic medical institution in August and September 2020. The virtual format included 5 hour-long sessions with presentations by peer experts in social media. Peer physicians with experience using social media presented on a range of topics, including introductions to platforms, how to reach and grow audiences, and use of social media to advance patient education, medical education, and advocacy. OUTCOMES: There were 425 cumulative registrations for the 5 sessions of the Social Media Summit. The number of registrants increased for each session, suggesting that interest increased over time. Qualitative and quantitative participant feedback was collected via a brief, voluntary survey. All of the participants who completed the survey (n = 24) reported they were "very satisfied" (58.3%) or "somewhat satisfied" (41.7%) with the Summit. NEXT STEPS: Physician involvement in social media presents opportunities for public health knowledge, medical education, scientific collaboration, and career advancement. Physicians who have been successful in using social media for these purposes are excellent peer educators and can fill the medical education void in social media training. Future plans include building sustainability of the program, collecting additional quantitative and qualitative feedback to guide improvement, and encouraging reproducibility.

Fertility preservation discussions, referral and follow-up in male-to-female and female-to-male adolescent transgender patients.

The number of patients seeking transgender healthcare is growing, and there is a potential impact of gender-affirming therapies on fertility. The use of fertility preservation (FP), particularly among transgender adolescents, has been limited. We aimed to examine differences in FP counselling, referral and utilisation between male-to-female (MtF) and female-to-male (FtM) transgender adolescents. A retrospective review of the medical records of patients ages 12-17 seen at an academic medical centre between 2012 and 2017 with a diagnosis of gender dysphoria was conducted. A total of 22 MtF and 45 FtM adolescents were included. The counselling on the potential fertility impact of gender-affirming therapy was documented in 55%, and of those counselled, 73% were counselled before receiving medication. There was no significant difference between the timing of counselling for MtF versus FtM adolescents. Of patients with documented reproductive wishes, 77% reported either desire for adopted children or no desire for biological children. Among patients offered FP referral, 2 (22.2%) MtF and 3 (12.5%) FtM patients accepted; both MtF patients cryopreserved sperm. While most adolescents were counselled on the fertility impact of gender-affirming therapy, there is room for improvement as 45% of patients had no documented counselling. The rate of transgender adolescents pursuing FP consultation and gamete cryopreservation was low, consistent with prior studies in this population.

Traits of patients seen via telemedicine versus in person for new-patient visits in a fertility practice.

OBJECTIVE: To assess the differences in demographics, the likelihood of receiving treatment, and the clinical outcomes between new patients seen via telemedicine and those seen in person in an academic fertility practice. DESIGN: Retrospective cohort study. SETTING: University-based fertility clinic. PATIENTS: All new patients seen via telemedicine between June 1, 2017, and February 29, 2020, were compared with an equal number of all new patients seen in person between May 1, 2019, and June 30, 2019. INTERVENTIONS: None. MAIN OUTCOME MEASURES: The primary outcome was receiving treatment after a new-patient visit. Binary logistic regression analyses were performed to estimate the odds ratio for not receiving treatment according to distance to the clinic and duration of infertility. The secondary outcomes included treatment recommendation, time to treatment initiation, and time to positive pregnancy test (if achieved). In addition we assessed patient demographics and visit traits per patient encounter. RESULTS: The telemedicine and in-person groups each contained 70 patients. The following were similar between the groups: age, body mass index, Area Deprivation Index, diagnosis made at the new-patient visit, and the number of clinic contacts before starting treatment. Compared with patients who had in-person new-patient visits, those who had telemedicine new-patient visits lived farther from the clinic (mean, 223.6 vs. 69.28 miles) and had a longer duration of infertility (mean, 41.9 vs. 19.49 months). No differences were noted between the groups in the following outcomes: percent that received treatment, time to treatment initiation, or time to pregnancy. Telemedicine new-patient visits were shorter than in-person new-patient visits (mean, 56.3 ± 9.1 vs. 59.3 ± 4.6 minutes) and less likely to contain documentation of height or weight. CONCLUSIONS: Telemedicine appears to be of particular interest to patients who live farther from clinics and have longer durations of infertility, and it could reduce visit times. New patients seen in person and those seen via telemedicine are equally likely to pursue treatment. Telemedicine consultation for new-patient visits is feasible in an academic fertility practice and may be especially useful during a pandemic and in non-pandemic times in areas with limited access to fertility specialists.

A randomized controlled trial to evaluate the use of a web-based application to manage medications during in vitro fertilization.

OBJECTIVE: To evaluate the use of a web-based application that assists in medication management during in vitro fertilization (IVF) treatment. DESIGN: Multicenter randomized controlled trial. SETTING: University hospitals. PATIENT(S): Women undergoing IVF. INTERVENTION(S): Subjects were recruited to assess quality of life during IVF and were randomly assigned to use either the OnTrack application to assist with medication management or conventional medication management. Surveys were administered at four time points. MAIN OUTCOME MEASURE(S): Medication surplus, incidence of medication errors, amount of patient-initiated communication, and patient satisfaction. RESULT(S): A total of 153 women participated. The average number of portal messages and telephone calls was similar between groups. Twelve patients in the control group (12/69, 17.4%) and 8 patients in the case group (8/72, 11.1%) made medication errors. There were similar amounts of medication surplus in the two groups. The estimated cost of medication waste was $2,578 ± $2,056 in the control group and $2,554 ± $1,855 in the case group. Patient satisfaction was similar between the two groups. CONCLUSION(S): Use of a web-based application did not decrease medication errors, medication surplus, or patient-initiated messages. Many patients had a medication surplus, which can be an area of cost reduction during IVF. CLINICAL TRIAL REGISTRATION NUMBER: Clinicaltrials.gov NCT03383848.

Successful oocyte cryopreservation using letrozole as an adjunct to stimulation in a transgender adolescent after GnRH agonist suppression.

OBJECTIVE: To report a successful case of ovarian hyperstimulation and oocyte cryopreservation in a transgender male adolescent after suppression with a gonadotropin-releasing hormone (GnRH) agonist while using the aromatase inhibitor letrozole to maintain low serum estradiol. DESIGN: Case report. SETTING: Division of Reproductive Endocrinology and Infertility, Washington University in St. Louis School of Medicine, St Louis, Missouri. PATIENT(S): A 15-year-old Tanner II transgender male adolescent with a GnRH agonist implant. INTERVENTION(S): The GnRH agonist implant was removed. The patient was given letrozole (5 mg daily) while undergoing ovarian stimulation with an antagonist protocol. After oocyte retrieval, the patient began taking testosterone. MAIN OUTCOME MEASURE(S): Successful oocyte cryopreservation with minimal changes in breast budding. RESULT(S): The patient's peak serum estradiol concentration was 510 pg/mL. Twenty-two mature oocytes were cryopreserved. Small increases in breast budding occurred between baseline and the time of oocyte retrieval. CONCLUSION(S): We successfully used letrozole to maintain low serum estradiol in a transgender male adolescent during ovarian stimulation. Maintaining low estradiol to minimize pubertal development and possibly prevent gender dysphoria symptoms may make oocyte cryopreservation more desirable for transgender male adolescents.

The Sertoli cell expressed gene secernin-1 (Scrn1) is dispensable for male fertility in the mouse.

BACKGROUND: Male infertility is a prevalent clinical presentation for which there is likely a strong genetic component due to the thousands of genes required for spermatogenesis. Within this study we investigated the role of the gene Scrn1 in male fertility. Scrn1 is preferentially expressed in XY gonads during the period of sex determination and in adult Sertoli cells based on single cell RNA sequencing. We investigated the expression of Scrn1 in juvenile and adult tissues and generated a knockout mouse model to test its role in male fertility. RESULTS: Scrn1 was expressed at all ages examined in the post-natal testis; however, its expression peaked at postnatal days 7-14 and SCRN1 protein was clearly localized to Sertoli cells. Scrn1 deletion was achieved via removal of exon 3, and its loss had no effect on male fertility or sex determination. Knockout mice were capable of siring litters of equal size to wild type counterparts and generated equal numbers of sperm with comparable motility and morphology characteristics. CONCLUSIONS: Scrn1 was found to be dispensable for male fertility, but this study identifies SCRN1 as a novel marker of the Sertoli cell cytoplasm.

Public reporting of IVF outcomes influences medical decision-making and physician training.

BACKGROUND: Since 1992 ART clinics have been required to report outcome data. Our objective was to assess practitioners' opinions of the impact of public reporting of assisted reproductive technology (ART) outcomes on treatment strategies, medical decision-making, and fellow training. METHODS: Survey study performed in an academic medical center. Members of the Society of Reproductive Endocrinology and Infertility and the Society of Reproductive Surgery were recruited to participate in an online survey in April 2012.: Categorical survey responses were expressed as percentages. Written responses were categorized according to common themes regarding effects of reporting on participants' medical management of patients. The study was primarily qualitative and was not powered to make statistical conclusions. RESULTS: Of 1019 surveys sent, 323 participants (31.7%) responded from around the United States, and 275 provided complete data. Nearly all (273 of 282; 96.8%) participants responded that public reporting sometimes or always affected other providers' practices, and 264 of 281 (93.9%) responded that other practitioners were motivated to deny care to poor-prognosis patients to improve reported success rates. However, only 121 of 282 (42.9%) indicated that public reporting influenced their own medical management. The majority of respondents agreed that public reporting may hinder adoption of single embryo transfer practices (194 of 299; 64.9%) and contribute to the persistent rate of twinning in in vitro fertilization (187 of 279; 67%). A small majority (153 of 279; 54.8%) felt that public reporting did not benefit fellow training, and 58 (61.7%) of the 94 participants who trained fellows believed that having fellows perform embryo transfers reduced pregnancy rates. A small majority (163 of 277; 58.8%) of respondents reported their ART success rates on clinical websites. However, the majority (200 of 275; 72.7%) of respondents compared their success rates with those of other clinics. Finally, most respondents (211 of 277; 76%) believed that most centers that advertised their success rates did so in ways that were misleading to patients. CONCLUSIONS: Public reporting of ART clinical outcomes is intended to drive improvement, promote trust between patients and providers, and inform consumers and payers. However, providers reported that they modified their practices, felt others denied care to poor-prognosis patients, and limited participation of trainees in procedures in response to public reporting of ART outcomes.

Outcomes of in vitro fertilization pregnancies complicated by subchorionic hematoma detected on first-trimester ultrasound.

OBJECTIVE: To estimate the association between subchorionic hematoma (SCH) on ultrasound and pregnancy outcomes in in vitro fertilization (IVF) pregnancies. DESIGN: Institutional Review Board-approved, retrospective cohort study. SETTING: Tertiary care university-based facility. PATIENTS: In this study, 1,004 patients who underwent IVF with a viable singleton pregnancy from January 1, 2009 through December 31, 2017. INTERVENTIONS: Subchorionic hematoma versus no hematoma diagnosed on first-trimester ultrasound. MAIN OUTCOME MEASURES: Live birth, preterm birth, and spontaneous abortion. RESULTS: We found that 1,004 women met the criteria and 187 (18.6%) had an SCH. In bivariate and multivariate regression models, there were no associations between SCH and the outcomes of live birth, preterm birth, or birth weight. CONCLUSIONS: Subchorionic hematoma detected on first-trimester ultrasound after IVF is not associated with probability of live birth, probability of preterm birth, or infant birth weight in this patient population.

Correction to: Effect of endometrial mechanical stimulation in an unselected population undergoing in vitro fertilization: futility analysis of a double-blind randomized controlled trial.

The original version of this article unfortunately contained mistakes. The complete list of corrections is given below.

Effect of endometrial mechanical stimulation in an unselected population undergoing in vitro fertilization: futility analysis of a double-blind randomized controlled trial.

PURPOSE: Implantation failure is a major limiting factor of successful in vitro fertilization (IVF). The objective of this study was to determine if endometrial mechanical stimulation (EMS) by endometrial biopsy in the luteal phase of the cycle prior to embryo transfer (ET) improves clinical outcomes in an unselected subfertile population. METHODS: Double-blind, randomized controlled trial of EMS versus sham biopsy and odds of clinical pregnancy after IVF and embryo transfer. Secondary outcomes included spontaneous miscarriage and live birth. RESULTS: One hundred women enrolled and were randomized from 2013 to 2017. Enrollment was terminated after futility analysis showed no difference in clinical pregnancy between EMS versus control, 47.2% vs 61.7% (OR 0.55, 95% CI 0.25-1.23, p = 0.15). There were no significant differences between women who underwent EMS and those who did not in terms of positive pregnancy test 54.7% vs 63.8% (OR 0.69, 95% CI 0.31-1.53, p = 0.36), miscarriage 7.5% vs 2.1% (OR 3.76 95% CI 0.41-34.85, p = 0.22), or live birth 43.4% vs 61.7% (OR 0.48 95% CI 0.21-1.06, p = 0.07). CONCLUSIONS: EMS in the luteal phase of the cycle preceding embryo transfer does not improve clinical outcomes in an unselected subfertile population and may result in a lower live birth rate. We caution the routine use of EMS in an unselected population.

Fellow Perceptions of Residency Training in Obstetrics and Gynecology.

OBJECTIVE: To evaluate the perceptions of current and former fellows in obstetrics and gynecology (OBG) subspecialties of their readiness for fellowship training. METHODS: A previously used survey was modified and distributed in 2016 to current and former fellows in gynecologic oncology, maternal-fetal medicine, reproductive endocrinology-infertility, and female pelvic medicine and reconstructive surgery. The survey explored domains of professionalism, independent practice, psychomotor ability, clinical evaluation, and scholarship. A standard Likert scale was employed and domains/responses were tailored to each subspecialty. Standard statistical models were utilized. RESULTS: A total of 478 fellows responded to the survey. Nearly 75% of fellows from each specialty reported feeling prepared or very prepared for fellowship. More than 65% of fellows from each specialty reported feeling very prepared to perform core surgical procedures. More than 90% of respondents reported having opportunities during residency to independently develop a plan of action for patients on labor and delivery. Fewer respondents reported opportunities to independently manage postoperative complications-40.7% of gynecologic oncology and 44.7% of female pelvic medicine and reconstructive surgery reported having such opportunities, whereas 91.9% of maternal-fetal medicine respondents reported having had such opportunities. While 46.4% of respondents received education on scientific writing during residency, 80% reported writing a manuscript as a resident. CONCLUSIONS: The majority of current and former fellows in OBG subspecialties report feeling prepared for fellowship in terms of clinical and surgical skills. Their feedback reveals opportunities for improvement of independent practice in gynecologic scenarios, as well as formal education on scientific research, for OBG residencies.

National mosaic embryo transfer practices: a survey.

BACKGROUND: The growing use of preimplantation genetic testing with in vitro fertilization has provided clinicians with more information about the genetics of embryos. Embryos, however, sometimes result with a mixed composition of both aneuploid and euploid cells, called mosaic embryos. The interpretation of these results has varied, leading some clinicians to transfer mosaic embryos and some opt not to. In addition, laboratories providing preimplantation genetic testing for aneuploidy have differing thresholds for determining an embryo aneuploid, mosaic, or euploid. Overall practice patterns for mosaic embryo transfer practices in the United States are unknown. OBJECTIVE(S): The objectives of the study were to characterize national mosaic embryo transfer practices, including the use of preimplantation genetic testing for aneuploidy, prior history of transferring mosaic embryos, thresholds for determining mosaicism, and willingness to transfer mosaic embryos among assisted reproductive technology clinics in the United States. STUDY DESIGN: A 14 question online survey assessing current use of preimplantation genetic testing for aneuploidy, thresholds for determining mosaicism, and clinic experience and willingness to transfer mosaic embryos was e-mailed to 405 assisted reproductive technology clinics across the United States. Descriptive statistics and logistic regression were used to analyze survey responses and identify clinical factors associated with reporting having ever transferred a mosaic embryo. RESULTS: Of the 405 US assisted reproductive technology clinics contacted, 252 (62.2%) completed a survey, including 157 private (62.3%), 55 academic (21.8%), and 40 hybrid (15.9%) clinics. Most clinics (168, 66.7%) reported conducting preimplantation genetic testing for aneuploidy on less than 50% of all in vitro fertilization cycles. The most common type of preimplantation genetic testing for aneuploidy technology used was next-generation sequencing at 88.9%. Ninety-one clinics (36.1%) receive mosaicism data on their preimplantation genetic testing for aneuploidy report; the most common thresholds for determining embryo aneuploidy and euploidy by clinics' primary genetics laboratories were <20% normal (36.3%) and >80% normal (46.2%), respectively. Thirty-nine (42.9%) of the 91 have transferred and 57 (62.6%) would transfer a mosaic embryo. Nearly 40% of clinics were unsure about their thresholds for mosaic transfer and one fourth of clinics reported they had no threshold. Private (odds ratio, 1.0, 95% confidence interval, 0.5-1.8) and hybrid (odds ratio, 0.9, 95% confidence interval, 0.4-2.1) clinics were just as likely as academic clinics to report having transferred a mosaic embryo. Clinics in the northeastern United States were more likely to have transferred a mosaic embryo than clinics in other regions (odds ratio, 1.5, 95% confidence interval, 0.9-2.7). Most clinics (72.6%) report they do not have a unique consent for transfer of mosaic embryos. CONCLUSION: There is uncertainty and variability in the transfer practices of mosaic embryos and classification of mosaicism among US assisted reproductive technology clinics. These findings provide an opportunity to establish mosaicism thresholds and create standardized guidelines for transferring mosaic embryos.