Society For Assisted Reproductive Technology Research Articles

Obstetric outcomes in pregnancies resulting from in vitro fertilization (IVF) are not different in fertile, sterilized patients compared to infertile women: a society for assisted reproductive technology (SART) database analysis

This study aims to compare obstetric outcomes resulting from assisted reproductive technology (ART) in couples with a history of female sterilization compared to those with other infertility diagnoses. Retrospective Cohort Study. All 760,705 fresh, autologous embryo transfer cycles with partner ejaculated sperm from 2004 to 2013 in the SART database were reviewed. Cycles in women with prior female sterilization were compared to cycles with other infertility diagnoses. After excluding cycles with male sterilization, day of transfer >7, prior sterilization with an additional infertility diagnosis, and unknown method of ICSI or IVF, 4,174 cycles in patients with history of female sterilization were compared to 179,605 cycles in patients with other causes of infertility. Multiple linear regression analyses and generalized estimating equations were performed to assess whether gestational length and birthweight were significantly different between groups in singleton and twin pregnancies after controlling for BMI, age, parity, and type of ART procedure (traditional IVF vs ICSI). Previously sterilized women were older with significantly higher parity and body mass indices than women in couples with all other causes of infertility. Number of oocytes retrieved, timing of embryo transfer, pregnancy and live birth rates were not significantly different between the two groups. Women with a history of sterilization had significantly shorter gestations and lower birth weights than women with other causes of infertility. However, there was no significant difference between these groups after controlling for singleton and twin gestations except in birth weight for twins.Tabled 1All Women (N=183779)Women with history of female sterilization (N=4174)Women with all other causes of infertility (N=179605)P-ValueAge (years)35.281 ± 4.05934.507 ± 4.604<0.0001Parity2.425 ± 1.1720.469 ± 0.710<0.0001Body Mass Index (BMI) (kg/m2)27.155 ± 5.50225.414 ± 15.321<0.0001Number of oocytes retrieved12.734 ± 7.48612.817 ± 7.6980.4794Day of Embryo Transfer3.712 ± 1.0483.705 ± 1.0440.6583Clinical Pregnancy Rate Per Cycle, n (%)1864 (44.66%)81689 (45.48%)0.2897Live Birth Rate Per Cycle, n (%)1544 (36.99%)67972 (37.85%)0.2605Lengthof Gestation, days250.479 ± 1.046252.667 ± 1.3780.0364Singletons Twins270.220 ± 1.051270.662 ± 1.3420.6739236.024 ± 1.924239.780 ± 2.7820.0509Live Birth Weight, grams2100.348 ± 37.1292275.679 ± 53.150<0.0001Singletons Twins3027.401 ± 139.1713142.228 ± 177.8790.40931978.822 ± 48.0002140.158 ± 73.5060.0008 Open table in a new tab Evidence has linked pregnancies resulting from ART with increased risk of adverse obstetric outcomes, including low birthweight; however, it is unclear if this is due to the ART procedures or to subfertility itself.1 This study provides a rare opportunity to evaluate the effects of ART in a population without an underlying infertility diagnosis. This analysis demonstrates no significant differences in neonatal birthweight or gestational age among ART births from women with infertility and tubal sterilization. The results suggest that differences in outcomes between ART and natural conceptions may be due to the procedures of ART itself.

Freezing of all embryos in in vitro fertilization is beneficial in high responders, but not intermediate and low responders: an analysis of 82,935 cycles from the Society for Assisted Reproductive Technology registry

To assess invitro fertilization (IVF) and pregnancy outcomes in patients having their first frozen embryo transfer (FET) after a freeze-all cycle versus similar patients having their first fresh embryo transfer (ET). Retrospective cohort study. None. Registry data on 82,935 patient cycles from the Society for Assisted Reproductive Technology (SART). All first fresh autologous IVF cycles were analyzed and compared to first FET cycles after a freeze-all first IVF stimulation. The cycles were subdivided into cohorts based upon the number of oocytes retrieved (OR): 1-5 (low), 6-14 (intermediate), and 15+ (high responders). Univariate analyses were performed on cycle characteristics, and multivariable regression analyses were performed on outcome data. Clinical pregnancy rate (CPR) and live-birth rate (LBR). Of the 82,935 cycles analyzed, 69,102 patients had their first fresh transfer, and 13,833 had a first FET. High responders were found to have a higher CPR and LBR in the FET cycles compared with the fresh ET cycles (61.5 vs. 57.4%; 52.0 vs. 48.9%). In intermediate responders, both CPR and LBR were higher after fresh ET compared with FET (49.6% vs. 44.2%; 41.2 vs. 35.3%). Similarly, in low responders, CPR and LBR were higher after fresh compared with FET (33.2% vs. 15.9%; 25.9% vs. 11.5%). A freeze-all strategy is beneficial in high responders but not in intermediate or low responders, thus refuting the idea that freeze-all cycles are preferable for all patients.

How PGS/PGT-A laboratories succeeded in losing all credibility

How PGS/PGT-A laboratories succeeded in losing all credibility

Limitations and opportunities in male fertility databases.

Over the last several years, the male component of reproduction has begun to gain clinical momentum. The medical literature has traditionally focused on infertility from the female perspective, but recent publications have demonstrated that male infertility is an important marker of overall health for infertile men as well as their family members. In order to perform large-scale, quality research related to male infertility, comprehensive databases are necessary. Currently, research in male infertility is limited by the fact that there is not a centralized, comprehensive database specifically designed to collect patient information related to male fertility. A database of this nature exists for female infertility research in the form of the Society for Assisted Reproductive Technology (SART) clinical summary report and the National ART Surveillance System (NASS) published by the Centers for Disease Control (CDC). This review outlines the strengths and weaknesses of several male fertility data sources, including the National Survey of Family Growth, the Reproductive Medicine Network, the Andrology Research Consortium (ARC), the Truven Health MarketScan® databases, the Utah Population Database, and data available from the Ober Lab related to the Hutterites. While each of these sources has been instrumental in the creation of meaningful research within the field of male fertility, a need remains for the creation of a centralized database for use in future male fertility research. The ideal database would consist of vast amounts of patient data which link individuals and couples to biologic specimens as well as data from family members, designed with parameters specifically purposed for male fertility research. The use of electronic medical records (EMR) systems such as Epic may play a role in the development of such a database going forward. At present, although some information is available through current databases, researchers must utilize suboptimal data sources to perform studies.

The pros and cons of the requirement by the Society for Assisted Reproductive Technology (SART) for their members who perform in vitro fertilization and related procedures to report their pregnancy rates to the center for disease control

Purpose: To present pros and cons of the requirement of in vitro fertilization (IVF) centers, to record their statistics, and make them public. Materials and Methods: Various tricks are presented as to how some IVF centers can “pad” their pregnancy rates. Results: Some of these “tricks” include not trying as hard with the patients’ own oocytes but steering them into donor oocyte programs because, though they could eventually get pregnant with their own eggs, it could be at the detriment of the given IVF center's pregnancy rates, which in turn, could be “bad for business”. Conclusions: Published statistics help a patient to choose an experienced center with a good pregnancy rate, but the consumer should not necessarily equate the IVF center with the highest pregnancy rates as the best center for their problem.

Public reporting of IVF outcomes influences medical decision making

In 1985 the Society for Assisted Reproductive Technology (SART) was created to establish a national registry of IVF outcomes (1). In 1992 congress passed the Fertility Clinic Success Rate and Certification Act which mandates public reporting of individual clinic outcomes (1). One unintended consequence of public reporting has been competition between fertility centers to publish superior results. This competition may unfavorably affect medical decision-making for fertility patients.

The correlation between raised body mass index and assisted reproductive treatment outcomes: a systematic review and meta-analysis of the evidence

BackgroundPublic funding for fertility services within the United Kingdom is limited, and therefore, strict guidance exists regarding who can be offered treatment under the National Health Service (NHS). Body mass index (BMI) is a universal criteria adopted by both the public and private sector.This study addresses an important aspect of the impact of a raised BMI on fertility treatment outcomes. We standardise the analysis of the data by only including studies incorporating the WHO BMI criteria; the current reference point for clinicians and clinical commissioning groups in ascertaining which group of patients should receive treatment. This study is an update of the previous systematic review performed in 2010, with the inclusion of a larger number of cycles from central databases such as the Society for Assisted Reproductive Technology (SART).MethodsAn electronic literature search was conducted through the Cochrane, Medline and Embase libraries. Data extraction for each outcome measure was pooled and expressed as an odds ratio with 95% confidence intervals. Where clinical heterogeneity was evident, the random effects model was used to calculate the risk ratio and a fixed effects model was used for the remaining studies. A p value < 0.05 was considered statistically significant.ResultsA total of 49 studies have been identified and included in this systematic review. Overweight and obese (BMI ≥ 25 kg/m2) women have a statistically significant lower live birth rate (OR 0.81, 95% CI 0.74–0.89, p < 0.00001) following Assisted Reproductive Technology (ART) when comparisons are drawn to women with a normal BMI. An increase is also demonstrated in the number of miscarriages experienced by women with a BMI ≥ 30 kg/m2 (OR 1.52, 95% CI 1.28–1.81, p < 0.00001).ConclusionAlthough this review concludes that a clear impact of BMI on ART outcomes is demonstrated, there remains questions as to the pathophysiology underlying these differences. This review supports the government’s stringent criteria regarding BMI categories under which NHS funding is made available for ART, through a clear description of poor reproductive outcomes in women with a BMI ≥ 30 kg/m2.

Assessing access to assisted reproductive services for serodiscordant couples with human immunodeficiency virus infection

To understand the barriers that serodiscordant couples with human immunodeficiency virus (HIV) face in accessing services for risk reduction and infertility using assisted reproductive technology (ART). Two-arm cross-sectional telephone "secret shopper" study. Infertility clinics designated by the Society for Assisted Reproductive Technology (SART), 140 from 15 American states with the highest prevalence of heterosexual HIV-infected men. Clinical and nonclinical staff at SART-registered clinics. Standardized telephone calls to SART-registered clinics by investigators in the roles of physician and patient callers. Availability and difference in services offered to callers and the rate of referral if the clinic did not provide these services. Of the 140 sampled SART clinics across 15 states, callers in both patient and physician roles spoke to a staff member at greater than 90% of targeted clinics (127 clinics total). Of the physician callers 63% were told that the clinic could offer services, as compared to 40% of patient callers. Of the 55 clinics that were unable to provide services to the patient caller, 51% referred to other clinics with confidence that they could offer these services; 67% of clinics would provide services for both prevention and infertility purposes. Risk reduction services for HIV were more available at the sampled fertility clinics than previously reported in the literature. However, the responses depended on the person calling. The clinics demonstrated low rates of concordance with the American Society for Reproductive Medicine's guidelines, which endorse referral of patients to other facilities from sites unable to offer services.

Earlier day of blastocyst development is predictive of embryonic euploidy across all ages: essential data for physician decision-making and counseling patients.

The purpose of this study is to evaluate whether day of blastocyst development is associated with embryo chromosomal status as determined by high-density oligonucleotide microarray comparative genomic hybridization (aCGH). This is a retrospective cohort analysis, including women who underwent in vitro fertilization (IVF) with trophectoderm biopsy at a single private fertility center from January 2014 to December 2014. Repeat cycles were excluded. Cycles were assessed for percentage of blastocysts biopsied on days 5, 6, or 7 and rate of euploid embryos per cycle. Cycles were stratified by Society for Assisted Reproductive Technology (SART) age groups (<35, 35-37, 38-40, 41-42, >42) and by donor status. A total of 388 IVF cycles and 2132 biopsied blastocysts were evaluated. The percentages of blastocysts biopsied on days 5, 6, and 7 were 62.5, 35.8, and 1.7%, respectively. Blastocyst euploid rates on days 5, 6, and 7 were 49.5, 36.5, and 32.9%, respectively. Earlier blastocyst development was associated with a significantly increased euploid rate (p<0.0001). Younger maternal age (p<0.0001) and higher number of blastocysts biopsied per patient (p=0.0063) were both independently associated with greater percentage of euploidy. Earlier blastocyst development is independently associated with a higher likelihood of embryonic euploidy in both autologous and donor embryos. In non-biopsied embryos, these data support selection of day 5 blastocysts for transfer over later-developing embryos. These results can assist with patient counseling regarding expectations and outcomes. To our knowledge, this is the first study to examine embryonic euploidy as stratified by both day of blastocyst development and SART age group.

Assessment of society for assisted reproductive technology (SART) member clinic websites on reported embryo transfer (et) procedures

Assessment of society for assisted reproductive technology (SART) member clinic websites on reported embryo transfer (et) procedures

Frozen embryo transfer is associated with a higher live birth rate using gestational carriers: an analysis of the 2014 society for assisted reproductive technology (SART) data

Frozen embryo transfer is associated with a higher live birth rate using gestational carriers: an analysis of the 2014 society for assisted reproductive technology (SART) data

Decreased clinical pregnancy and live birth rates after short interval from delivery to subsequent assisted reproduction attempt: an analysis of 51,997 society for assisted reproductive technology (SART) cycles

Short interpregnancy interval (IPI) has been associated with poor maternal and neonatal outcomes in the naturally conceiving population. Patients with a prior live birth from assisted reproductive technology (ART) may want to initiate treatment sooner given a history of infertility, particularly in the setting of advanced maternal age. However, no data exist regarding the interval following delivery that will optimize conception with ART. We aim to determine whether the interval from delivery to initiation of a subsequent treatment cycle (delivery-to-cycle-interval, DCI) is associated with rate of clinical pregnancy or live birth.

Leveraging online patient reviews to improve quality of care: art-specific insights for practice administrators and physicians

To identify factors that contribute to positive patient experience in clinical ART setting through patients’ ratings of physicians and IVF centers, and determine whether online patient reviews and ratings can be used as a reliable indicator of provider service quality. Cross-sectional study. Online reviews and ratings by patients were collected from FertilityIQ, a patient review site of U.S. IVF centers and reproductive endocrinology physicians. Outcome data for the year 2012, the latest available during the time of data compilation in 2016, was gathered from publicly available data reported by the Society for Assisted Reproductive Technology (SART). 120 IVF centers with the largest number of total ART cycles reported to SART in 2012 were included. 5 centers that could not be confidently identified in FertiltiyIQ were then excluded, leaving 115 centers in the analyses. In 2012, a vast majority (87.1%) of the centers performed fewer than 2000 cycles, with just a handful of large centers performing up to 7000+ cycles.The number of patient ratings per IVF center varied greatly (9.35 +/- 1.97). However, most (85.3%) of the centers received fewer than 15 ratings. Consistent with a prior analysis in other medical specialties1, a vast majority of reviewers rated the centers positively, with a mean overall score of 8.30 (+/- 0.31) out of 10. Individual physician ratings were similarly high at 8.34 +/- 0.30. Contrary to common fear in the industry, ratings were not dominated by disgruntled patients, with only 7% of them giving ratings below 5.Among the factors analyzed, average physician ratings, smooth operations and nursing team excellence were the most highly correlated with overall positive ratings for IVF centers. Counter-intuitively, but consistent with a prior finding in cardiac surgery2, fresh total live birth rates (LBR) reported to SART were not predictive of positive overall ratings. Also consistent with a prior study of surgeon ratings3, the number of total fresh cycles performed was not significantly correlated with positive overall ratings. While the limited number of ratings make generalization difficult, this study found that management of operational and administrative factors are just as important as interactions with clinicians when it comes to ensuring positive patient experience. As more physician practices rely on online review sites to improve performance4, ART-specific online rating sites with nuanced and thorough prompts has a potential to provide insights to practice administrators working to improve patient experience.The results of this study confirm prior findings in other specialties that higher volume and better clinical outcomes do not necessarily result in better patient experience and higher online ratings. Patients are well advised to use the online ratings to complement the insights garnered from published ART outcome data when selecting a center, rather than relying one or the other in isolation.

Developments in IVF warrant the adoption of new performance indicators for ART clinics, but do not justify the abandonment of patient-centred measures.

Recent advances in embryo freezing technology together with growing concerns over multiple births have shifted the paradigm of appropriate IVF. This has led to the adoption of new performance indicators for ART clinics by national reporting schemes, such as those curated by the Society for Assisted Reproductive Technology (SART) and the Human Fertilization and Embryology Authority (HFEA). Using these organizations as case studies, we review several outcome measures from a statistical perspective. We describe several denominators that are used to calculate live birth rates. These include cumulative birth rates calculated from all fresh and frozen transfer procedures arising from a particular egg collection or cycle initiation, and live birth rates calculated per embryo transferred. Using data from both schemes, we argue that all cycles should be included in the denominator, regardless of whether or not egg collection and fertilization were successful. Excluding cancelled cycles reduces the impact of confounding due to patient characteristics but also removes policy and performance differences which we argue represent relevant sources of variation. It may be misleading to present prospective patients with essentially hypothetical measures of performance predicated on parity of ovarian stimulation and transfer policies. Although live birth per embryo has the advantage of encouraging single embryo transfer, we argue that it is prone to misinterpretation. This is because the likelihood of live birth is not proportional to the number of embryos transferred. We conclude that it is not possible to present a single measure that encompasses both effectiveness and safety. Instead, we propose that a set of clear, relevant outcome indicators is necessary to enable subfertile patients to make informed choices regarding whether and where to be treated.

Success rates vary by ovulation induction protocol and body mass index: toward personalized medicine for intrauterine insemination

Obesity rates are increasing worldwide. Along with others, we have demonstrated that body mass index (BMI) influences fertility treatment success rates in a protocol-dependent fashion. Much less is known about intrauterine insemination (IUI) success because of the absence of IUI data in national reporting registries, such as the one maintained by the Society for Assisted Reproductive Technologies (SART). To investigate the effectiveness of ovulation induction with gonadotropins versus ovulation induction with oral agents and gonadotropins (aka “mini-stim”) in relation to BMI in patients undergoing IUI in a large, multi-center, retrospective analysis. We analyzed 67,662 treatment cycles from 33,867 patients undergoing IUI ovulation induction (OI) with gonadotropins alone versus oral agents and gonadotropin from 2009 to 2016. Discrete-time proportional-odds models with time-dependent covariates were used to model the odds of achieving ongoing pregnancy during a given cycle. Interaction terms between BMI and stimulation type were included in the models to test the hypothesis that the effect of BMI was modified by stimulation type. BMI was treated continuously and categorized according to NIH guidelines (<18.5, 18.5–25, 25–30, 30–35, >35). Models were adjusted for age, antral follicle count, medication type, sperm motility, clinic, diagnoses, and were weighted toward more recent data. Overall, OI with only gonadotropin agents had significantly higher odds of achieving ongoing pregnancy compared to OI with oral agents and gonadotropins (OR = 1.16, p < 0.05). However, we found that the impact of BMI on success rates also differed significantly with the type of IUI treatment protocol. The effect of BMI was nonlinear and peaked in the obesity categories of both protocols (p < 0.05, see Figure 1). At lower levels of BMI, there was no significant difference in the odds of having an ongoing pregnancy between stimulation types. However, there was a pronounced divergence in success rate as BMI increased; gonadotropin OI alone performed better than gonadotropin OI with oral agents. When subcategories of BMI were assessed, a statistically significant difference in success was observed in women with a BMI of 25–30. Additionally, gonadotropin OI alone was associated with higher odds of multiples than gonadotropin with oral agents (OR = 1.53, p < 0.05), independent of patient BMI. Oral OI agents when used in conjunction with gonadotropins appear to be less effective for obese women. We previously demonstrated oral agents alone result in lower pregnancy rates with both timed intercourse and IUI in obese women. However, the detrimental effect of increased BMI was not observed with gonadotropin alone. Here, we demonstrate that OI with only gonadotropin agents is associated with higher success rates than OI with oral agents and gonadotropins. This difference is most pronounced in higher BMI patients. Additionally, we demonstrated gonadotropin OI alone is related to a higher probability of multiples than oral and gonadotropin independent of BMI. These data suggest that the best IUI protocol for a given patient varies with respect to their BMI.

Use of Intracytoplasmic Sperm Injection and Birth Outcomes in Women Conceiving through In Vitro Fertilization.

Despite questionable evidence of benefits over conventional in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) use has markedly increased in recent decades among couples without male factor infertility. We assessed the frequency of ICSI use and its effect on birth outcomes. A retrospective cohort study was conducted in 141 030 women conceiving through IVF using 2006-2010 data from the Society for Assisted Reproductive Technology (SART). Between 2006 and 2010, overall ICSI use in women conceiving through IVF increased from 68.9% to 73.1%. This increase was greater among women without male factor infertility (53.0-59.2%) than in women with male factor infertility (92.0-93.4%). Women conceiving through IVF with and without ICSI had similar rates of multiple pregnancy, preterm delivery, stillbirth, and neonatal death. However, ICSI pregnancies were associated with an increased risk of birth defects over conventional IVF (3.0% for ICSI vs. 2.5% for conventional IVF; adjusted odds ratio (OR) 1.2, 95% confidence interval (CI) 1.2, 1.3). These increases were observed in both women conceiving through ICSI with male factor infertility (3.2% vs. 2.5%; OR 1.4, 95% CI 1.3, 1.5) and without male factor infertility (2.7% vs. 2.5%; OR 1.1, 95% CI 1.1, 1.2). Higher rates of birth defects were observed among women conceiving through ICSI. Since approximately half of all ICSI procedures are performed in couples without male factor infertility, ICSI may be overused in practice.

State of the ART: Assisted Reproductive Technologies in the United States.

This review provides a brief look at the state of the assisted reproductive technologies (ARTs) in the United States in 2016. In 2013, the most recent year for which data are available through the Society for Assisted Reproductive Technology (SART) of the American Society for Reproductive Medicine (ASRM) and the Centers for Disease Control and Prevention (CDC), there were 190 773 total cycles of ART. Live births ranged from 40.1% per cycle initiated in women younger than 35 years to 4.5% live births per cycle initiated in women older than 42 years. US clinics must report their outcomes to the CDC. Society for Assisted Reproductive Technology clinics must report through the SART, which maintains rigorous quality assurance and validation programs. Society for Assisted Reproductive Technology member clinics must abide by minimum standards set by the SART and the ASRM, which include educational and other requirements for professionals participating in in vitro fertilization programs as well as standards for the laboratories. Assisted reproductive technology in the United States is a highly regulated field on a voluntary basis with excellent clinical results.

Society for Assisted Reproductive Technology and assisted reproductive technology in the United States: a 2016 update

The Society for Assisted Reproductive Technology (SART) was established within a few years of assisted reproductive technology (ART) in the United States, and has not only reported on the evolution of infertility care, but also guided it toward improved success and safety. Moving beyond its initial role as a registry, SART has expanded its role to include quality assurance, data validation, practice and advertising guidelines, research, patient education and advocacy, and membership support. The success of ART in this country has greatly benefited from SART's role, as highlighted by a series of graphs. SART continues to set the standard and lead the way.

How compliant are in vitro fertilization member clinics in following embryo transfer guidelines? An analysis of 59,689 fresh first in vitro fertilization autologous cycles from 2011 to 2012

To determine whether IVF clinics are compliant with American Society for Reproductive Medicine (ASRM) and Society for Assisted Reproductive Technology (SART) (ASRM/SART) guidelines and assess the multiple pregnancy outcomes according to the number of embryos transferred. Retrospective cohort study. Not applicable. Data from 59,689 fresh first autologous IVF cycles from the 2011-2012 SART registry. None. Percentage of compliant cycles, multiple pregnancy rate (PR). Between 2011 and 2012, a total of 59,689 fresh first autologous cycles were analyzed. Among cleavage-stage ET cycles, the noncompliance rate ranged from 10%-27.4% depending on the age group. The multiple PR was significantly increased in noncompliant cycles involving patients <35years (38.1% vs. 28.7%) and 35-37years (35.4% vs. 24.5%) compared with compliant cycles. Among blastocyst-stage ET cycles, the highest rate of noncompliance was seen in patients <35years old (71%), which resulted in a statistically higher multiple PR (48.3% vs. 2.8%) compared with compliant cycles. Far fewer cycles were noncompliant in patients 35-40years of age. In a subanalysis of compliant cycles, transferring two blastocyst embryos in patients 35-37years and 38-40years resulted in a higher live birth rate compared with the transfer of one embryo (50.4% vs. 40.9% and 42.1% vs. 30.0%, respectively) but the multiple PR was also significantly higher (40.5% vs. 1.7% and 34.0% vs. 2.0%, respectively). Most first fresh autologous IVF cycles performed from 2011-2012 were compliant with ASRM/SART guidelines, except those that involved a blastocyst ET in patients <35years. Despite compliance, cycles that involved the transfer of >1 embryo resulted in a high multiple PR, whereas noncompliant cycles resulted in an even more remarkable multiple PR for both cleavage and blastocyst-stage embryos. Clinics need to be more compliant with ET limits and ASRM/SART need to consider revising their guidelines to limit the number of blastocyst transfer to one in patients ≤40years of age undergoing their first IVF cycle. Furthermore, decreasing the number of cleavage-stage embryos transferred in patients ≤40years of age should also be considered.

A Review of The Society for Assisted Reproductive Technology Embryo Grading System and Proposed Modification.

The Society for Assisted Reproductive Technology (SART) method of embryo grad- ing is unique, simple, and widely practiced, and its use has been mandatory for SART membership programs since 2010. Developed by SART in 2006, the current embryo grading system categories, "good, fair, and poor," are limited because they do not describe the best 1-2 embryos in the interest of keeping pace with the shift in clinical practice to be more selective and to transfer fewer embryos. This inspired us to conduct a review on the SART embryo grading system. In this retrospective study, the literature on evaluation of human embryo quality in gen- eral, and the SART method of evaluation in particular, were reviewed for the period of 2000 to 2014. A multifaceted search pertaining to methods of embryo grading and trans- fer using a combination of relevant terms [embryo, mammalian, embryo transfer, grade, grading, morphology, biomarkers, SART, and in vitro fertilization (IVF)] was performed. The inclusion and exclusion in this review were dictated by the aim and scope of the study. Two investigators independently assessed the studies and extracted information. A total of 61 articles were reviewed. Very few studies have evaluated the efficacy of the SART embryo grading method. The present study suggests the necessity for revision of the current SART grading system. The system, as it is now, lacks criteria for describing the cohort specific best embryo and thus is of limited use in single embryo transfer. The study foresees heightened descriptive efficiency of the SART system by implementing the proposed changes. Strengths and weaknesses of the SART embryo grading were identified. Ideas for selecting the best cohort-specific embryo have been discussed, which may trigger methodological improvement in SART and other embryo grading systems.