Biological predictive criteria for clinical pregnancy after elective single embryo transfer

Factors predicting double embryo implantation following double embryo transfer in assisted reproductive technology: implications for elective single embryo transfer

PURPOSE

The aim of this study was to identify factors associated with double embryo implantation following double embryo transfer (DET) during assisted reproductive technology (ART) procedures and to evaluate the implications of findings in selecting candidates for elective single embryo transfer (eSET).

METHODS

Factors predicting double embryo implantation, defined as embryo transfers with two or more heartbeats on 6-week ultrasound following DET, were assessed using the US National ART Surveillance System data from 2000 to 2012 (n = 1,793,067 fresh, autologous transfers). Adjusted risk ratios (aRRs) were estimated after stratifying by prognosis. Favorable prognosis was defined as first-time ART with supernumerary embryo(s) cryopreserved. Average prognosis was defined as first-time ART without supernumerary embryo(s) cryopreserved, prior unsuccessful ART with supernumerary embryo(s) cryopreserved, or prior ART with previous birth(s) conceived with ART or naturally. Rates and factors associated with double embryo implantation were compared with single embryo implantation following DET among both prognosis groups.

RESULTS

Double embryo implantation was positively associated with blastocyst (versus cleavage) transfer in favorable (aRR = 1.58 (1.51-1.65)) and average (aRR = 1.67 (1.60-1.75)) prognosis groups and negatively associated with age >35 years in both prognosis groups. For average prognosis patients, double embryo implantation was associated with retrieving >10 oocytes (aRR = 1.22 (1.18-1.24)).

CONCLUSIONS

Regardless of prognosis, patients aged <35 years with blastocyst-stage embryos and average prognosis patients from whom >10 oocytes were retrieved may be good candidates for eSET. Physicians may consider using these data to counsel patients on eSET, which would reduce multiple gestations and associated complications.

The German Middleway as Precursor for Single Embryo Transfer. A Retrospective Data-analysis of the Düsseldorf University Hospital's Interdisciplinary Fertility Centre - UniKiD

Introduction: Patients receiving fertility treatment in Germany appear to be disadvantaged in comparison to those in other countries due to the restrictive Embryo Protection Act ("Embryonenschutzgesetz, ESchG"), which prohibits the selection of a "top" embryo. The so-called German Middleway ("Deutscher Mittelweg, DMW") now provides for a liberal interpretation of the ESchG by allowing the culture of numerous pronuclear stages (2PN stage). Materials and Methods: Retrospective cohort study of 2 assisted reproduction treatment cycles in n = 400 patients between the ages of 21 and 45 years, either treated 2× conservatively or 1× conservatively and 1× liberally according to DMW. Results: Pregnancy was achieved in 35 % of patients in the DMW group and 31 % of controls. The birth rate among controls was 28.5 % and 30.5 % in the DMW group. Most pregnancies resulted from the culture of 4 × 2PN stages. Conclusion: Patients in the DMW group had significantly higher pregnancy and birth rates compared to their previous cycles despite significantly increased age and significantly fewer transferred embryos. Key factors were the number of 2PNs generated and the quality of embryos transferred. Thus it can be assumed that particularly older patients with adequate ovarian reserves will benefit from DMW, i.e. the transfer of fewer embryos of the best possible quality.

Clinical predictive criteria associated with live birth following elective single embryo transfer

OBJECTIVE

We aimed to define clinical criteria from the patients related to the occurrence of live birth in case of elective single embryo transfer (eSET).

STUDY DESIGN

We analyzed retrospectively 409 eSET at day 2/3 between March 2005 and July 2012, proposed in case of (i) woman's age <37 years, (ii) first/second IVF0 cycle, (iii) ≥2 good quality embryos obtained (3-5/6-10 blastomeres at day 2/3 and <20% fragmentation), including one top embryo (4/8 cells). In all, 124/409 live births (30.3%) were obtained, separating patients into groups of women who had birth or not. Different clinical parameters of interest were compared between each group, using appropriate statistical tests at p<0.05 significance level.

RESULTS

By comparing Body Mass Index (BMI), we report a statistically higher BMI among women who did not deliver (24.6 vs. 23.4kg/m(2); p=0.014). Using an analysis by BMI categories, we also precise a threshold of BMI≥30kg/m(2), negatively associated with the occurrence of live birth.

CONCLUSION

BMI appears to be the only clinical parameter statistically associated with delivery following eSET strategy in a good prognosis infertile population.

[How can we nowadays select the best embryo to transfer?]

Multiple pregnancies stand as the most common adverse outcome of assisted reproduction technologies (ART) and the dangers associated with those pregnancies have been reduced by doing elective single embryo transfers (e-SET). Many studies have shown that e-SET is compatible with a continuously high pregnancy rate per embryo transfer. Yet, it still becomes necessary to improve the selection process in order to define the quality of individual embryos - so that the ones we choose for transfer are more likely to implant. First, analysis of embryo morphology has greatly helped in this identification and remains the most relevant criterion for choosing the embryo. The introduction of time-lapse imaging provides new criteria predictive of implantation potential, but the real contribution of this system - including the benefit/cost ratio - seems to be not yet properly established. In this context, extended culture until blastocyst stage is an essential practice but it appears wise to keep it for a population showing a good prognosis. Then, the failure of aneuploid embryos to implant properly led to achieve preimplantation genetic screening (PGS) in order to increase pregnancy and delivery rates after ART. However, PGS by fluorescence in situ hybridization (FISH) at day 3 is a useless process - and may even be harmful. Another solution involves using comparative genomic hybridisation (CGH) and moving to blastocyst biopsy. Finally, it is envisaged that morphology will also be significantly aided by non-invasive analysis of biomarkers in the culture media that give a better reflection of whole-embryo physiology and function.

Tumor necrosis factor-308 polymorphism increases the embryo implantation rate in women undergoing in vitro fertilization

STUDY QUESTION

Do TNF-308 and -238 polymorphisms impact the embryo implantation rate after in vitro fertilization (IVF) in women without female infertility factor?

SUMMARY ANSWER

The presence of the TNF-308A allele is associated with high implantation and multiple pregnancy rates in women without known infertility factors after ovarian hyperstimulation with exogenous FSH.

WHAT IS ALREADY KNOWN

Multiple pregnancies are frequent after the use of Assisted Reproductive Technologies. Single embryo transfer (SET) has been proposed as a simple way to prevent these risks. However, the extension of SET indications to patients not selected based on specific criteria is controversial because of reduced pregnancy rates. To date, the predictive value of the parameters used for SET (age, gynecological history of the patient and uterine characteristics) allows a pregnancy rate of ~30%.

STUDY DESIGN, SIZE, DURATION

The potential predictive value of TNF polymorphisms (-308, rs1800629 and -238, rs361525) on implantation rate was evaluated in 424 women requiring IVF due to male fertility factors. This cohort retrospective study was conducted over 4 years in University-affiliated hospitals.

PARTICIPANTS, SETTING, METHODS

The entire patient group included 424 women undergoing intracytoplasmic sperm injection (ICSI) due to male fertility factors without the contribution of any female factor. From among this group, a selected patient group included 120 women with a normal karyotype, age under 38 years, serum follicle-stimulating hormone (Day-3 FSH) levels below 10 IU/l, a long agonist desensitization protocol associated with recombinant FSH treatment and a Caucasian background.

MAIN RESULTS AND THE ROLE OF CHANCE

The TNF-238 polymorphism was not associated with implantation rate. In contrast, the presence of the TNF-308A allele was associated with increased Day 3-E2 levels as well as higher implantation and multiple pregnancy rates after fresh embryo transfer in women from the entire and selected patient groups. Moreover, in the selected patient group, the presence of the TNF-308A allele was also associated with a decrease in the miscarriage rate. The benefit of the TNF-308A allele in predicting implantation rates was not observed after the use of frozen embryos.

LIMITATIONS, REASONS FOR CAUTION

Future studies are needed to evaluate whether the TNF-308A allele might also be a biomarker in women with infertility factors.

WIDER IMPLICATIONS OF THE FINDING

The TNF-308A allele may represent a good candidate for a potential predictive, non-invasive biomarker in the SET strategy. However, its impact should be evaluated in prospective studies.

STUDY FUNDING/COMPETING INTEREST

This study was conducted with financial support from the French Institute for Health and Medical Research (INSERM), Organon France for a FARO (Fond d'Aide à la Recherche Organon) fellowship (to V.T.) and CHU Nice PHRC (PHRC 09-279).There are no competing interests.

Elective single embryo transfer trends and predictors of a good perinatal outcome--United States, 1999 to 2010

OBJECTIVE

To assess trends in elective single ET and identify factors associated with a good perinatal outcome.

DESIGN

Retrospective cohort study.

SETTING

Clinic-based data.

PATIENT(S)

A total of 886,686 fresh, nondonor cycles reported to the National Assisted Reproductive Technology Surveillance System during 1999-2010, of which 17,166 met criteria for elective single ET.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Rates of elective single ET and good perinatal outcome (term, singleton infant with normal birth weight).

RESULT(S)

In 2010, elective single ET comprised 5.6% of all fresh transfers, representing an eightfold increase since publication of first guidelines in 2004 recommending elective single ET. Compared with other ETs, elective single ETs were nearly twice as likely to result in a good perinatal outcome (37.1% vs. 18.9%, respectively). Among women using elective single ET, those aged <35 and 35-37 years had a good perinatal outcome (40.2% and 32.5%, respectively). In multivariable, log-binomial analyses, factors positively associated with a good perinatal outcome included male factor infertility, day 5 ET, and having ≥3 supernumerary embryos for cryopreservation.

CONCLUSION(S)

Between 1999 and 2010, national rates of elective single ET increased. Given the frequency of good perinatal outcomes among women aged 35-37 years, guidelines for elective single ET could be expanded to include patients in this age group with favorable prognoses.

Clinical factors associated with live birth after single embryo transfer

OBJECTIVE

To identify patient, cycle, and retrieval characteristics associated with embryo implantation and live birth in patients undergoing single embryo transfer (SET).

DESIGN

Analysis of prospectively collected IVF database.

SETTING

Academic IVF program.

PATIENT(S)

All patient cycles meeting criteria for SET between June 2004 and September 2010.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy and live birth.

RESULT(S)

Single embryo transfer was performed in 438 cycles, resulting in a clinical pregnancy rate of 76.2% and a live birth rate of 66.8% per transfer. Clinical pregnancy was associated with younger female age, ≥ 58% mature (metaphase II) oocytes at the time of retrieval, and increasing blastocyst expansion. Ongoing pregnancy was associated with younger female age and more advanced blastocysts. A diagnosis of uterine factor was negatively associated with live birth.

CONCLUSION(S)

Even in a favorable prognosis population, younger female age is associated with clinical pregnancy and live birth. Although all patients underwent blastocyst transfer, expanded and hatching blastocysts were strongly associated with pregnancy and live birth. A diagnosis of uterine factor was the only infertility diagnosis found to affect live birth after SET. Obesity did not negatively affect SET outcome. These findings may assist physicians in determining the best candidates for SET.