Embryo cryopreservation and utilization in the United States from 2004-2013

Too many embryos: a critical perspective on a global challenge

Over the past decade, significant endeavors have been directed toward establishing an optimal oocyte number to maximize the chances for successful in vitro fertilization outcomes. The effectiveness of assisted reproductive technologies has greatly improved, and more good-quality embryos are being created in each cycle. However, many of these embryos remain unused. Notably, in Europe, approximately one-third of couples did not use their surplus cryopreserved embryos. Surplus embryos pose a challenge for patients and clinics. Embryo disposal practices are not the same all over the continent, with embryo donation and embryo discharge not allowed in several countries. In this scenario, limiting the number of surplus embryos by reducing the number of inseminated oocytes, according to couple clinical history, could be a strategy.

One size does not fit all: the personal nature of completed embryo donation

PURPOSE

To assess factors associated with embryo donation among individuals interested in donation in the United States.

METHODS

An invitation to complete the 123-item survey was emailed from June to September 2022 to patients at a private practice fertility clinic with interest in donation at the time of IVF. Survey questions included disposition decision, attitudes about embryo status and genetic relatedness, donation disclosure, ideal donation arrangement, and decision satisfaction.

RESULTS

Three hundred thirty-seven completed the survey. Two hundred thirty donated to another person(s), 75 discarded embryos, 25 remained undecided, and disposition was unknown for 7 respondents. There were no demographic differences between groups based on final disposition or use of donor gametes. Few gamete recipients were interested in donation due to biological attachment to embryos. Final embryo disposition was associated with religious factors, not wanting to waste embryos, and storage fee concerns. Final disposition was also significantly associated with concern about donor-conceived children's (DCP) welfare, being denied the ability to complete donation, personal IVF outcomes, financial or legal issues, future contact with DCP, cognitive appraisal of disposition, beliefs about embryos, someone else raising their genetic child, anonymity, and beliefs about DCP not knowing genetic relationships (p < .001). Donation to others was associated with less regret and greater satisfaction with the emotional/medical aspects of donation and counseling compared to those who discarded embryos (p < .001).

CONCLUSION

The decision to donate embryos to another person(s) is complex. Counseling that considers individual circumstances, values, and evolving dynamics may facilitate informed decision-making for those navigating infertility treatment, family building, and embryo disposition.

Oocyte and embryo cryopreservation in assisted reproductive technology: past achievements and current challenges

Cryopreservation has revolutionized the treatment of infertility and fertility preservation. This review summarizes the milestones that paved the way to the current routinary clinical implementation of this game-changing practice in assisted reproductive technology. Still, evidence to support "the best practice" in cryopreservation is controversial and several protocol adaptations exist that were described and compared here, such as cumulus-intact vs. cumulus-free oocyte cryopreservation, artificial collapse, assisted hatching, closed vs. open carriers, and others. A last matter of concern is whether cryostorage duration may impact oocyte/embryo competence, but the current body of evidence in this regard is reassuring. From social and clinical perspectives, oocyte and embryo cryopreservation has evolved from an afterthought when assisted reproduction was intended for immediate pregnancy with supernumerary embryos of secondary interest to its current purpose, which primarily is to preserve fertility long-term and more comprehensively allow for family planning. However, the initial consenting process, which still is geared to short-term fertility care, may no longer be relevant when the individuals that initially preserved the tissues have completed their reproductive journey. A more encompassing counseling model is required to address changing patient values over time.

Natural cycle frozen embryo transfer: a survey of current assisted reproductive technology practices in the U.S

PURPOSE

Emerging data suggests improved obstetric outcomes with frozen embryo transfer (FET) in an ovulatory or natural cycle (NC-FETs), as compared to programmed endometrial preparation. The objective of this study is to better understand practice patterns and provider attitudes regarding the use of NC-FETs in the United States (U.S.).

METHODS

In this cross-sectional study, an anonymous 22-question survey was emailed to 441 U.S. Assisted Reproductive Technology (ART) clinics to assess the utilization of NC endometrial preparation for FET, protocols used, restrictions to offering NC-FET, and providers' perspectives on advantages and disadvantages of NC-FET. Descriptive statistics were used to analyze survey responses.

RESULT(S)

The survey response rate was 49% (216/441). Seventeen percent of responding clinics did not offer NC-FET. Of the clinics that did not offer NC-FET, 65% had only 1-2 physicians in their practice. Common reasons for not offering NC-FET included "lack of timing predictability for transfer" (81%) and "increased burden on staff/laboratory personnel on holidays and weekends" (54%). Of clinics offering NC-FET, 76% reported < 25% of cycles used the NC for endometrial preparation. Over half (52%) of clinics that offered NC-FET reported having eligibility restrictions for NC-FET. Reported benefits of NC-FET were "patient satisfaction" (18%), "decreased cost of medications" (18%), and "avoidance of intramuscular progesterone" (17%). The attitude towards NC-FET in their clinics was reported as positive by 65% of respondents.

CONCLUSION

NC-FETs are offered by most U.S. ART clinics but are used only in the minority of FET cycles for endometrial preparation, and use is often restricted.

Assisted Reproductive Technology without Embryo Discarding or Freezing in Women ≥40 Years: A 5-Year Retrospective Study at a Single Center in Italy

The protocols commonly used in assisted reproductive technology (ART) consist of long-term embryo culture up to the blastocyst stage after the insemination of all mature oocytes, the freezing of all the embryos produced, and their subsequent transfer one by one. These practices, along with preimplantation genetic testing, although developed to improve the live birth rate (LBR) and reduce the risk of multiple pregnancies, are drawing attention to the possible increase in obstetric and perinatal risks, and adverse epigenetic consequences in offspring. Furthermore, ethical-legal concerns are growing regarding the increase in cryopreservation and storage of frozen embryos. In an attempt to reduce the risk associated with prolonged embryo culture and avoid embryo storage, we have chosen to inseminate a limited number of oocytes not exceeding the number of embryos to be transferred, after two days or less of culture. We retrospectively analyzed 245 ICSI cycles performed in 184 infertile couples with a female partner aged ≥40 from January 2016 to July 2021. The results showed a fertilization rate of 95.7%, a miscarriage rate of 48.9%, and a LBR of 10% with twin pregnancies of 16.7%. The cumulative LBR in our group of couples was 13%. No embryos were frozen. In conclusion, these results suggest that oocyte selection and embryo transfer at the cleaving stage constitute a practice that has a LBR comparable to that of the more commonly used protocols in older women who have reduced ovarian reserve.

Development of a Model to Estimate the Optimal Number of Oocytes to Attempt to Fertilize During Assisted Reproductive Technology Treatment

IMPORTANCE

Surplus cryopreserved embryos pose a challenge for in vitro fertilization patients and clinics; with Roe v. Wade overturned, some states may deem the discarding of surplus embryos illegal, radically changing in vitro fertilization practice. An evidence-based tool would help limit surplus embryo creation.

OBJECTIVE

To develop a prediction tool for determining how many oocytes should be exposed to sperm to create embryos to conserve the chance of live birth while minimizing surplus embryos.

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic study used data from member clinics of the Society for Assisted Reproductive Technology Clinical Outcomes Reporting System between 2014 to 2019. A total of 410 719 oocyte retrievals and 460 577 embryo transfer cycles from 311 237 patients aged 18 to 45 years old who initiated their first oocyte stimulation cycle between January 1, 2014, and December 31, 2019, were included. Data were analyzed from February to June 2022.

EXPOSURES

Female patient age, anti-mullerian hormone level, diminished ovarian reserve diagnosis, number of oocytes retrieved, and the state where the clinic is located were included in the final models.

MAIN OUTCOMES AND MEASURES

The algorithm was based on 3 models with outcomes: (1) day of transfer; (2) proportion of retrieved oocytes that become usable blastocysts; and (3) number of blastocysts needed for transfer for 1 live birth to occur.

RESULTS

The median (IQR) age at stimulation cycle start was 35 (29-32) years and the median (IQR) number of oocytes retrieved was 10 (6-17). The likelihood of recommending that all oocytes be exposed to sperm increased with age; less than 20.0% of retrievals among patients younger than 32 years and more than 99.0% of retrievals among patients older than 42 years received recommendations that all oocytes be exposed to sperm. Among cycles recommended to expose fewer than all oocytes, the median (IQR) numbers recommended for 1 live birth were 7 oocytes (7-8) for patients aged less than 32 years, 8 (7-8) for patients aged 32 to 34 years, and 9 (9-11) for patients aged 35 to 37 years.

CONCLUSIONS AND RELEVANCE

In this diagnostic study of in vitro fertilization cycles, a prediction tool was developed to aid clinicians in determining the optimal number of oocytes to expose to sperm, reducing the number of unused embryos created and immediately addressing current patient and clinician concerns.

Assessment of patients' perceptions towards embryo disposition after donation of embryos to a research biobank

PURPOSE

To explore perceptions towards embryo disposition among patients donating excess embryos to a research biobank.

METHODS

Cross-sectional study of survey responses collected as part of enrollment in a research biobank. Patients are asked questions regarding the difficulty of their disposition decision, their alternative disposition choice if donation to research was not available, quality of the counseling they received, and if additional counseling throughout their treatment would have been beneficial. Survey responses use 5-point Likert scales, with "1" being lowest/least and "5" being highest/most.

RESULTS

A total of 157 men and 163 women enrolled in the biobank. Median scores for difficulty of disposition decision were 3 for females and 2 for males, and for quality of counseling, the median scores were 4 for females and 3 for males. Seventy percent of patients would have chosen to discard their excess embryos had donation to research not been an option. Statistical analyses showed no significant difference in responses based on variations in race, religion, sexual orientation, and infertility diagnoses. Concordance of responses within heterosexual couples was tested and found to be poor to moderate.

CONCLUSIONS

Assessing patients' perceptions towards embryo disposition after donation of their excess embryos to a research biobank affords a unique perspective. The difficulty of the disposition decision, the tendency to discard embryos in the absence of a means for donation to research, and the poor agreement between heterosexual partners highlight the importance of donation to research as an accessible disposition option and the need for a personalized approach to counseling and consenting for embryo disposition.

Embryo transfer-the who, what, when, how, and why does it matter?

Embryo transfer is the ultimate step in the in vitro fertilization process and is the culmination of months to years of preparation. Many factors contribute to embryo transfer success before, during, and after the transfer. This series is a comprehensive review of the factors that converge to influence embryo transfer success. Robust discussion is included regarding the impact of the physician who performs the transfer, adjunct therapies used, timing of embryo transfer, endometrial receptivity, and resultant health of the pregnancy and offspring.

Ovarian Stimulation in Assisted Reproductive Technology Cycles for Varied Patient Profiles: An Indian Perspective

Controlled ovarian stimulation has been an integral part of in vitro fertilisation (IVF) treatment cycles. Availability of different gonadotropins for ovarian stimulation and gonadotropin releasing hormone (GnRH) analogues for prevention of premature rise of leutinising hormone during follicular phase offer an opportunity to utilise them for a successful outcome in women with different subsets of ovarian response. Further, use of GnRH agonist as an alternative for human chorionic gonadotropin improves safety of ovarian stimulation in hyper-responders. Mild ovarian stimulation protocols have emerged as an alternative to conventional protocols in the recent years. Individualisation plays an important role in improving safety of IVF in hyper-responders while efforts continue to improve efficacy in poor responders. Some of the follicular and peri-ovulatory phase interventions may be associated with negative impact on the luteal phase and segmentalisation of the treatment with frozen embryo transfer may be an effective strategy in such a clinical scenario. This narrative review looks at the available evidence on various aspects of ovarian stimulation strategies and their consequences. In addition, it provides a concise summary of the evidence that has emerged from India on various aspects of ovarian stimulation.

Storage, transport, and disposition of gametes and embryos: legal issues and practical considerations

Cryopreservation of reproductive material has dramatically improved clinical outcomes for patients all over the world. At the same time the practice has produced significant legal, ethical, and practical challenges to physicians and practices who use this technique. Failing to meet the expectations of patients, for example by losing material because of a freezer failure, has significant implications for the reproductive facility. Similarly, improperly transporting or receiving gametes or embryos can result in substantial risk to a practice. Perhaps the most widely publicized conundrum is how best to manage embryos that are abandoned. This paper will describe the legal principles and best practices that should be incorporated into the management of a fertility cryopreservation program.