Is it justified to transfer two embryos in oocyte donation? A pilot randomized clinical trial

ESHRE Guideline Group on the Number of Embryos to Transfer, Alteri A, Arroyo G, Baccino G, Craciunas L, De Geyter C, Ebner T, Koleva M, Kordic K, Mcheik S, Mertes H, Pavicic Baldani D, Rodriguez-Wallberg KA, Rugescu I, Santos-Ribeiro S, Tilleman K, Woodward B, Vermeulen N, Veleva Z. ESHRE guideline: number of embryos to transfer during IVF/ICSI†

STUDY QUESTION

Which clinical and embryological factors should be considered to apply double embryo transfer (DET) instead of elective single embryo transfer (eSET)?

SUMMARY ANSWER

No clinical or embryological factor per se justifies a recommendation of DET instead of eSET in IVF/ICSI.

WHAT IS KNOWN ALREADY

DET is correlated with a higher rate of multiple pregnancy, leading to a subsequent increase in complications for both mother and babies. These complications include preterm birth, low birthweight, and other perinatal adverse outcomes. To mitigate the risks associated with multiple pregnancy, eSET is recommended by international and national professional organizations as the preferred approach in ART.

STUDY DESIGN, SIZE, DURATION

The guideline was developed according to the structured methodology for development and update of ESHRE guidelines. Literature searches were performed in PUBMED/MEDLINE and Cochrane databases, and relevant papers published up to May 2023, written in English, were included. Live birth rate, cumulative live birth rate, and multiple pregnancy rate were considered as critical outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on the collected evidence, recommendations were discussed until a consensus was reached within the Guideline Development Group (GDG). A stakeholder review was organized after the guideline draft was finalized. The final version was approved by the GDG and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

The guideline provides 35 recommendations on the medical and non-medical risks associated with multiple pregnancies and on the clinical and embryological factors to be considered when deciding on the number of embryos to transfer. These recommendations include 25 evidence-based recommendations, of which 24 were formulated as strong recommendations and one as conditional, and 10 good practice points. Of the evidence-based recommendations, seven (28%) were supported by moderate-quality evidence. The remaining recommendations were supported by low (three recommendations; 12%), or very low-quality evidence (15 recommendations; 60%). Owing to the lack of evidence-based research, the guideline also clearly mentions recommendations for future studies.

LIMITATIONS, REASONS FOR CAUTION

The guideline assessed different factors one by one based on existing evidence. However, in real life, clinicians' decisions are based on several prognostic factors related to each patient's case. Furthermore, the evidence from randomized controlled trials is too scarce to formulate high-quality evidence-based recommendations.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides health professionals with clear advice on best practice in the decision-making process during IVF/ICSI, based on the best evidence currently available, and recommendations on relevant information that should be communicated to patients. In addition, a list of research recommendations is provided to stimulate further studies in the field.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, the literature searches, and the dissemination of the guideline. The guideline group members did not receive payment. DPB declared receiving honoraria for lectures from Merck, Ferring, and Gedeon Richter. She is a member of ESHRE EXCO, and the Mediterranean Society for reproductive medicine and the president of the Croatian Society for Gynaecological Endocrinology and Reproductive Medicine. CDG is the past Chair of the ESHRE EIM Consortium and a paid deputy member of the Editorial board of Human Reproduction. IR declared receiving reimbursement from ESHRE and EDCD for attending meetings. She holds an unpaid leadership role in OBBCSSR, ECDC Sohonet, and AER. KAR-W declared receiving grants for clinical researchers and funding provision to the institution from the Swedish Cancer Society (200170F), the Senior Clinical Investigator Award, Radiumhemmets Forskningsfonder (Dnr: 201313), Stockholm County Council FoU (FoUI-953912) and Karolinska Institutet (Dnr 2020-01963), NovoNordisk, Merck and Ferring Pharmaceuticals. She received consulting fees from the Swedish Ministry of Health and Welfare. She received honoraria from Roche, Pfizer, and Organon for chairmanship and lectures. She received support from Organon for attending meetings. She participated in advisory boards for Merck, Nordic countries, and Ferring. She declared receiving time-lapse equipment and grants with payment to institution for pre-clinical research from Merck pharmaceuticals and from Ferring. SS-R received research funding from Roche Diagnostics, Organon/MSD, Theramex, and Gedeo-Richter. He received consulting fees from Organon/MSD, Ferring Pharmaceuticals, and Merck Serono. He declared receiving honoraria for lectures from Ferring Pharmaceuticals, Besins, Organon/MSD, Theramex, and Gedeon Richter. He received support for attending Gedeon Richter meetings and participated in the Data Safety Monitoring Board of the T-TRANSPORT trial. He is the Deputy of ESHRE SQART special interest group. He holds stock options in IVI Lisboa and received equipment and other services from Roche Diagnostics and Ferring Pharmaceuticals. KT declared receiving payment for honoraria for giving lectures from Merck Serono and Organon. She is member of the safety advisory board of EDQM. She holds a leadership role in the ICCBBA board of directors. ZV received reimbursement from ESHRE for attending meetings. She also received research grants from ESHRE and Juhani Aaltonen Foundation. She is the coordinator of EHSRE SQART special interest group. The other authors have no conflicts of interest to declare.

DISCLAIMER

This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgement to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose (full disclaimer available at https://www.eshre.eu/Guidelines-and-Legal).

Effect of frozen-thawed embryo transfer with a poor-quality embryo and a good-quality embryo on pregnancy and neonatal outcomes

BACKGROUND

To evaluate the impact of embryo quality and quantity, specifically a poor quality embryo (PQE) in combination with a good quality embryo (GQE), by double embryo transfer (DET) on the live birth rate (LBR) and neonatal outcomes in patients undergoing frozen-thawed embryo transfer (FET) cycles.

METHODS

A study on a cohort of women who underwent a total of 1462 frozen-thawed cleavage or blastocyst embryo transfer cycles with autologous oocytes was conducted between January 2018 and December 2021. To compare the outcomes between single embryo transfer (SET) with a GQE and DET with a GQE and a PQE, propensity score matching (PSM) was applied to control for potential confounders, and a generalized estimating equation (GEE) model was used to determine the association between the effect of an additional PQE and the outcomes. Subgroup analysis was also performed for patients stratified by female age.

RESULTS

After PS matching, DET-GQE + PQE did not significantly alter the LBR (adjusted odds ratio [OR] 1.421, 95% CI 0.907-2.228) compared with SET-GQE in cleavage-stage embryo transfer but did increase the multiple birth rate (MBR, [OR] 3.917, 95% CI 1.189-12.911). However, in patients who underwent blastocyst-stage embryo transfer, adding a second PQE increased the live birth rate by 7.8% ([OR] 1.477, 95% CI 1.046-2.086) and the multiple birth rate by 19.6% ([OR] 28.355, 95% CI 3.926-204.790), and resulted in adverse neonatal outcomes. For patients who underwent cleavage-stage embryo transfer, transferring a PQE with a GQE led to a significant increase in the MBR ([OR] 4.724, 95% CI 1.121-19.913) in women under 35 years old but not in the LBR ([OR] 1.227, 95% CI 0.719-2.092). The increases in LBR and MBR for DET-GQE + PQE compared with SET-GQE in women older than 35 years were nonsignificant toward. For patients who underwent blastocyst-stage embryo transfer, DET-GQE + PQE had a greater LBR ([OR] 1.803, 95% CI 1.165-2.789), MBR ([OR] 24.185, 95% CI 3.285-178.062) and preterm birth rate (PBR, [OR] 4.092, 95% CI 1.153-14.518) than did SET-GQE in women under 35 years old, while no significant impact on the LBR ([OR] 1.053, 95% CI 0.589-1.884) or MBR (0% vs. 8.3%) was observed in women older than 35 years.

CONCLUSIONS

The addition of a PQE has no significant benefit on the LBR but significantly increases the MBR in patients who underwent frozen-thawed cleavage-stage embryo transfer. However, for patients who underwent blastocyst-stage embryo transfer, DET-GQE + PQE resulted in an increase in both the LBR and MBR, which may lead to adverse neonatal outcomes. Thus, the benefits and risks of double blastocyst-stage embryo transfer should be balanced. In patients younger than 35 years, SET-GQE achieved satisfactory LBR either in cleavage-stage embryo transfer or blastocyst-stage embryo transfer, while DET-GQE + PQE resulted in a dramatically increased MBR. Considering the low LBR in women older than 35 years who underwent single cleavage-stage embryo transfer, selective single blastocyst-stage embryo transfer appears to be a more promising approach for reducing the risk of multiple live births and adverse neonatal outcomes.

Funding and public reporting strategies for reducing multiple pregnancy from fertility treatments

The health of children born through assisted reproductive technologies (ART) is particularly vulnerable to policy decisions and market forces that play out before they are even conceived. ART treatment is costly, and public and third-party funding varies significantly between and within countries, leading to considerable variation in consumer affordability globally. These relative cost differences affect not only who can afford to access ART treatment, but also how ART is practiced in terms of embryo transfer practices, with less affordable treatment creating a financial incentive to transfer more than one embryo to maximize the pregnancy rates in fewer cycles. One mechanism for reducing the burden of excessive multiple pregnancies is to link insurance coverage to the number of embryos that can be transferred; another is to combine supportive funding with patient and clinician education and public reporting that emphasizes a "complete" ART cycle (all embryo transfers associated with an egg retrieval) and penalizes multiple embryo transfers. Improving funding for fertility services in a way that respects clinician and patient autonomy and allows patients to undertake a sufficient number of cycles to minimize moral hazard improves outcomes for mothers and babies while reducing the long-term economic burden associated with fertility treatments.

Number of embryos for transfer following in vitro fertilisation or intra-cytoplasmic sperm injection

BACKGROUND

Transfer of more than one embryo during in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) increases multiple pregnancy rates resulting in an increased risk of maternal and perinatal morbidity. Elective single embryo transfer offers a means of minimising this risk, but this potential gain needs to be balanced against the possibility of jeopardising the overall live birth rate (LBR).

OBJECTIVES

To evaluate the effectiveness and safety of different policies for the number of embryos transferred in infertile couples undergoing assisted reproductive technology cycles.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group specialised register of controlled trials, CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform from inception to March 2020. We handsearched reference lists of articles and relevant conference proceedings. We also communicated with experts in the field regarding any additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different policies for the number of embryos transferred following IVF or ICSI in infertile women. Studies of fresh or frozen and thawed transfer of one to four embryos at cleavage or blastocyst stage were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial eligibility and risk of bias. The primary outcomes were LBR and multiple pregnancy rate. The secondary outcomes were clinical pregnancy and miscarriage rates. We analysed data using risk ratios (RR), Peto odds ratio (Peto OR) and a fixed effect model.

MAIN RESULTS

We included 17 RCTs in the review (2505 women). The main limitation was inadequate reporting of study methods and moderate to high risk of performance bias due to lack of blinding. A majority of the studies had low numbers of participants. None of the trials compared repeated single embryo transfer (SET) with multiple embryo transfer. Reported results of multiple embryo transfer below refer to double embryo transfer. Repeated single embryo transfer versus multiple embryo transfer in a single cycle Repeated SET was compared with double embryo transfer (DET) in four studies of cleavage-stage transfer. In these studies the SET group received either two cycles of fresh SET (one study) or one cycle of fresh SET followed by one frozen SET (three studies). The cumulative live birth rate after repeated SET may be little or no different from the rate after one cycle of DET (RR 0.95, 95% CI (confidence interval) 0.82 to 1.10; I² = 0%; 4 studies, 985 participants; low-quality evidence). This suggests that for a woman with a 42% chance of live birth following a single cycle of DET, the repeated SET would yield pregnancy rates between 34% and 46%. The multiple pregnancy rate associated with repeated SET is probably reduced compared to a single cycle of DET (Peto OR 0.13, 95% CI 0.08 to 0.21; I² = 0%; 4 studies, 985 participants; moderate-quality evidence). This suggests that for a woman with a 13% risk of multiple pregnancy following a single cycle of DET, the risk following repeated SET would be between 0% and 3%. The clinical pregnancy rate (RR 0.99, 95% CI 0.87 to 1.12; I² = 47%; 3 studies, 943 participants; low-quality evidence) after repeated SET may be little or no different from the rate after one cycle of DET. There may be little or no difference in the miscarriage rate between the two groups. Single versus multiple embryo transfer in a single cycle A single cycle of SET was compared with a single cycle of DET in 13 studies, 11 comparing cleavage-stage transfers and three comparing blastocyst-stage transfers.One study reported both cleavage and blastocyst stage transfers. Low-quality evidence suggests that the live birth rate per woman may be reduced in women who have SET in comparison with those who have DET (RR 0.67, 95% CI 0.59 to 0.75; I² = 0%; 12 studies, 1904 participants; low-quality evidence). Thus, for a woman with a 46% chance of live birth following a single cycle of DET, the chance following a single cycle of SET would be between 27% and 35%. The multiple pregnancy rate per woman is probably lower in those who have SET than those who have DET (Peto OR 0.16, 95% CI 0.12 to 0.22; I² = 0%; 13 studies, 1952 participants; moderate-quality evidence). This suggests that for a woman with a 15% risk of multiple pregnancy following a single cycle of DET, the risk following a single cycle of SET would be between 2% and 4%. Low-quality evidence suggests that the clinical pregnancy rate may be lower in women who have SET than in those who have DET (RR 0.70, 95% CI 0.64 to 0.77; I² = 0%; 10 studies, 1860 participants; low-quality evidence). There may be little or no difference in the miscarriage rate between the two groups.

AUTHORS' CONCLUSIONS

Although DET achieves higher live birth and clinical pregnancy rates per fresh cycle, the evidence suggests that the difference in effectiveness may be substantially offset when elective SET is followed by a further transfer of a single embryo in fresh or frozen cycle, while simultaneously reducing multiple pregnancies, at least among women with a good prognosis. The quality of evidence was low to moderate primarily due to inadequate reporting of study methods and absence of masking those delivering, as well as receiving the interventions.

Early Onset Preeclampsia Diagnosis Prior to the 20th Week of Gestation in a Twin Pregnancy Managed via Selective Reduction of an Intrauterine Growth Restriction Fetus: A Case Report and Literature Review

A single, healthy, 44-year-old perimenopausal woman pursuing a pregnancy, employed donor embryos, resulting to a dichorionic diamniotic twin pregnancy. In the 18th week of gestation severe symptoms indicated early onset preeclampsia reporting severe hypertension (BP 180/90 mmHg), intense headaches and nausea as well as elevated 24-h urine protein levels (1.5 g/day). Concurrently diagnosis of an IUGR fetus was concluded. Standard pharmaceutical administration for treating preeclampsia was ordered. Persistence of symptoms indicated recommendation for pregnancy termination, however the patient opted against this. Selective embryo reduction was performed as the last resort prior to pregnancy termination. Following selective reduction the headaches and nausea were successfully subdued and the patient’s blood pressure was adjusted (mean BP 130/80 mmHg). This enabled further progression of pregnancy for an impressive 11 week-period, and a live birth on the 30th week. To conclude, only a few rare cases have been reported with diagnosis of early onset preeclampsia prior to the 20th week mark and none report live births. Albeit termination of pregnancy was recommended, the management of selective reduction of the IUGR fetus enabled successful treatment of preeclampsia coupled by a live birth of a healthy infant without any perinatal or postnatal complications reported.

Single or double embryo transfer? Decision-making process in patients participating in an oocyte donation program

In IVF/ICSI programs, after receiving the information about the success results of single embryo transfer (SET) vs double embryo transfer (DET) and the risks of multiple pregnancy, a significant number of patients opt for SET. Up to date, no comparable studies have been published in oocyte recipients. The aim of this study was to evaluate if the counseling provided to oocyte recipients influence their decision on the number of embryos to be transferred. Fifty-five recipients expressed their preference and the relevance for the decision-making process that they attribute to certain factors through an anonymous questionnaire completed pre and post-counseling. Before counseling, 32 out of 55 recipients preferred DET, 13 preferred SET and 10 were undecided. From the 32 recipients who preferred DET, 16 (50%) maintained their preference after counseling, 13 (40.6%) changed their decision to SET and 3 (9.4%) changed to undecided (McNemar's test: p < .05). After counseling, the patients attached less importance to the probability of pregnancy and more importance to maternal and perinatal risks (p < .05). We conclude that after counseling, a significant number of recipients changed their preferences from DET to SET.

Promoting the use of elective single embryo transfer in clinical practice

Background

The transfer of multiple embryos after in vitro fertilization (IVF) increases the risk of twins and higher-order births. Multiple births are associated with significant health risks and maternal and neonatal complications, as well as physical, emotional, and financial stresses that can strain families and increase the incidence of depression and anxiety disorders in parents. Elective single embryo transfer (eSET) is among the most effective methods to reduce the risk of multiple births with IVF.

Main body

Current societal guidelines recommend eSET for patients <35 years of age with a good prognosis, yet even this approach is not widely applied. Many patients and clinicians have been reluctant to adopt eSET due to studies reporting higher live birth rates with the transfer of two or more embryos rather than eSET. Additional barriers to eSET include risk of treatment dropout after embryo transfer failure, patient preference for twins, a lack of knowledge about the risks and complications associated with multiple births, and the high costs of multiple IVF cycles. This review provides a comprehensive summary of strategies to increase the rate of eSET, including personalized counseling, access to educational information regarding the risks of multiple pregnancies and births, financial incentives, and tools to help predict the chances of IVF success. The use of comprehensive chromosomal screening to improve embryo selection has been shown to improve eSET outcomes and may increase acceptance of eSET.

Conclusions

eSET is an effective method for reducing multiple pregnancies resulting from IVF. Although several factors may impede the adoption of eSET, there are a number of strategies and tools that may encourage the more widespread adoption of eSET in clinical practice.

Outcomes of elective cryopreserved single or double embryo transfers following failure to conceive after fresh single embryo transfer

The main adverse effect of IVF is the high multiple pregnancy rate resulting from the transfer of two or more embryos. The objective was to evaluate pregnancy rates in infertile women with a good prognosis who failed to conceive in a fresh elective single embryo transfer (eSET) and had a second cycle with elective double vitrified-warmed embryo transfer (eDFET) compared with elective single vitrified-warmed embryo transfer (eSFET). A total of 142 intracytoplasmic sperm injection cycles using a conventional protocol were evaluated. Good-prognosis patients underwent eSET in a fresh cycle, and those who failed to conceive underwent a second vitrified-warmed embryo transfer: eDFET (n = 102) or eSFET (n = 40). Embryos were transferred and vitrified on day 5 of development. Patients who received eDFET had fewer implantations (30.9%) than eSFET (52.5%; P = 0.004); pregnancy rates were similar (eDFET: 35.3%, eSFET: 42.5%). Patients with the eSFET had one monozygotic twin (5.9%), and 22.2% of eDFET patients had multiple pregnancies. Patients with a good prognosis who failed to conceive in the first fresh eSET did not have an advantage when receiving eDFET in the second cycle, as pregnancy rates were similar; 22.2% of patients in the eDFET group had multiple pregnancies.