Optimum number of embryos to transfer in women more than 40 years of age undergoing treatment with assisted reproductive technologies

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).

Decline in Female Fertility After 40 Years

Important factor related to the conception possibility is women age. The decline in fertility with aging is proven and evident in literature. Infertility is increasing and many couples seek help in advanced techniques such as IVF (in vitro fertilization) in order to overcome the problem caused by aging, but the quality of the oocytes is a significant limiting factor. With the aging the quantity and quality of oocytes decreases, such as the quality of the embryo after fertilization. The accelerated rhythm of life, liberty and women inclusion in all kinds of professions brought many benefits to women, but also increasingly postponing births. Each person is unique individual, and can be more or less fertile compared to the average at same age. Unfortunately, some women has a rapid decline in fertility - accelerate aging, very early, already in the early twenties and when testing them with different methods and exams, the result is very low number of oocytes, low value of anti-Müllerian hormone and also very poor quality of these oocytes, or low ovarian reserve. The problem is that when you have accelerate aging, even IVF techniques can not be of great help in achieving pregnancy. The pregnancy rate (17,65%) and the childbirth rate (5,88%) with the patients older than 40 is very low, although comparable to the data from the scientific literature and speaks in favour of the fact that the success of assisted reproductive techniques is very modest with women older than 44.

Management of infertility in women over 40

Women's fertility potential is declining with age because of multiples intrinsic and extrinsic factors such as life style, oxidative stress and/or endocrine disruptors and is affecting the ability of these women to conceive naturally. This declining fertility potential and the late age of motherhood is increasing significantly the number of patients consulting infertility specialists. Different strategies of investigation and management are proposed to patients over 40 in order to overcome their infertility and improve the live birth rate in these patients. Intra Uterine Insemination (IUI) in women over 40 is associated with a low rate of ongoing pregnancy and IUI should not therefore be offered always as the first line of treatment. When the predictive factors are positive IVF/ICSI seem to be good alternatives until 43 years of age. Customized ovarian stimulation and flexible laboratory methods such as in vitro maturation (IVM), preimplantation genetic diagnosis (PGD), embryo vitrification and transfer after thawing in subsequent natural or artificial cycles can improve the success rate of ART in patients over 40. Meanwhile, oocyte and embryos donation remain good options for patient over 40 with a bad prognosis and can lead to successful ongoing pregnancies until 45 years of age. Ovarian tissue cryopreservation, oocyte vitrification at the germinal vesicle (GV) stage or metaphase II stage present a breakthrough for fertility preservation but the ideal age for starting fertility preservation is still debated as well as the minimum number of oocytes to be vitrified in order to optimize the chances of pregnancy when needed at an older age. This manuscript reports the results of our own experience from patients older than 40 in the light of the published data and discusses the different therapeutic alternatives which can be proposed to patients over 40 consulting ART centres.

Temporal Trends in the Rates of Multiple Maternities in England and Wales

After a long continuous decrease, the twinning and higher multifetal rates in many developed countries have increased during the last 2 to 3 decades. This change has been attributed to delayed childbearing and to increased use of subfertility treatments, particularly in women over 35 years of age. In this study we analyze how these new trends depend on changes in the effect of maternal age on the rates of multiple maternities. Our study is based on data for England and Wales for the period 1938 to 2003. The temporal variations show a decreasing trend to a trough around 1980 and after that a steady increase. This increase was more marked for higher multifetal rates and was particularly high for quadruplets. Furthermore, we identified changes in the age-specific rates resulting in increased levels for older mothers. These findings are in good agreement with our results from Nordic populations.

[Single embryo transfer: is Scandinavian model valuable in France?]

The aim of infertility treatment is clearly to obtain one healthy baby. If the transfer of a top quality single embryo could provide a baby to all the patients, there would be no more discussion. The problem is that, nowadays, French pregnancy rates after fresh embryo or frozen embryo transfer are not the same as in Nordic countries. All studies show that in unselected patients, single embryo transfer decreases twin pregnancy rate but decreases pregnancy rate too. Pregnancy rate is dependent on embryo quality, women's age, rank of IVF attempt (clear data) but also on body mass index, ovarian reserve, smoking habits. All these data cannot be taken into account in a law. That is the reason why a flexible policy of transfer adapted to each couple is preferable. Each couple and each IVF team are unique and must keep the freedom to choose how many embryos must be transferred to obtain healthy babies, and to avoid twin pregnancies but without demonizing them.

Optimizing the number of cleavage stage embryos to transfer on day 3 in women 38 years of age and older: a Society for Assisted Reproductive Technology database study

OBJECTIVE

To determine the optimal number of day 3 embryos to transfer in women >or=38 years by conducting an evidence-based evaluation.

DESIGN

Retrospective analysis of 2000-2004 national SART data.

SETTING

National writing group.

PATIENT(S)

A total of 36,103 day 3 embryo transfers in women >or=38 years undergoing their first assisted reproductive technology cycle.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Logistic regression was used to model the probability of pregnancy, delivery, and multiple births (twin or high order) based on age- and cycle-specific parameters.

RESULT(S)

Pregnancy rates, delivery rates, and multiple rates increased up to transfer of three embryos in 38-year-olds and four in 39-year-olds; beyond this number, only multiple rates increased. In women >or=40 years, delivery rates and multiple rates climbed steadily with increasing numbers transferred. Multivariate analysis confirmed the statistically significant effect of age, number of oocytes retrieved, and embryo cryopreservation on delivery and multiple rates. Maximum FSH level was not an independent predictor by multivariate analysis. Use of intracytoplasmic sperm injection was associated with lowered delivery rate.

CONCLUSION(S)

No more than three or four embryos should be transferred in 38- and 39-year-olds, respectively, whereas up to five embryos could be transferred in >or=40-year-olds. Numbers of embryos to transfer should be adjusted according to number of oocytes retrieved and availability of excess embryos for cryopreservation.

Prise en charge en Assistance médicale à la procréation des femmes de 38 ans et plus: résultats d'une enquête à propos de 84 couples

OBJECTIVE

More and more young women are delaying childbearing until the fourth decade of life: thus, Assisted Reproductive Techniques centres receive more and more requests from ageing women. The aim of the study is to analyse the purpose of these requests, the biological and clinical features of these patients and the results in our infertility centre.

PATIENTS AND METHODS

A retrospective study was carried out at the CHU of Saint-Etienne from 01.01.01 to 31.12.04. We analysed the social, clinical and biological features of 84 couples when the woman's age was equal or superior to 38 years, representing 218 cycles. A questionnaire was used to collect social data.

RESULTS

Several factors can explain the increasing number of ageing women consulting for infertility: extend university time and professional career, professional stability, contraception and late meeting of the partner, false reassuring information concerning progress in ART, second child desire after a late first pregnancy, but also second marital unions and child desire in the redefined couple. In our study, above 40 years old, the pregnancy (19.4 versus 10.5%) and delivery rates (16.7 versus 5.8%) clearly decreased in IUI. Thus, most of the clinicians propose, in first choice, an IVF cycle to a 40 year-old woman. The ultrasound measurement of antral follicle count can accurately evaluate the prognosis in terms of pregnancy (P<0.01) and delivery rate (P=0.03). For patients with unfavourable prognosis, oocyte donation, embryo donation, or adoption can be considered.

DISCUSSION AND CONCLUSION

ART cannot compensate for the natural decrease in pregnancy rates and the increase in early miscarriages in ageing women. Therefore, it is essential to inform young women of the negative effects of age on their potential fertility.

Outcome of 1114 ICSI and embryo transfer cycles of women 40 years of age and over

The purpose of this study was to contribute to the development of strategies to obtain acceptable outcomes in assisted reproduction treatments in women over 40 years of age. A retrospective study was carried out on the database of the German Hospital in Istanbul using data from the years 1997 to 2004. A total of 1114 embryo transfer cycles were assessed. The pregnancy, implantation and delivery rates of the assessed population were 18.2, 8.3 and 10.9% respectively. The results showed that the demographics and outcome of cycles of women at 40 years differed significantly from those over 40. Cycles in which six or more oocytes were retrieved displayed better characteristics and outcome than those with five or fewer. The clinical pregnancy and delivery rates after transfer of three embryos were similar to four or more. Therefore, women over 40 years with a good ovarian response and at least three embryos available for transfer have an acceptable pregnancy and delivery rate with a low multiple pregnancy risk.