Many variables must be considered when choosing a clinical culture system. Although animal studies provide a strong evidence-based profile as to the composition of viable clinical systems, the true test of efficacy in a clinical setting is to test the system within one's own laboratory by randomizing sibling oocytes or embryos to the test system or the standard system currently in use. Using this methodology, clinical results can be maximized while minimizing the potential impact on patients.

Objective: To determine the incidence, developmental potential, and clinical implications of embryos having one pronucleus (1PN) or three pronuclei (3PN) at early cleavage, despite exhibiting 2PN at the fertilization check.Design: Retrospective cohort study.Setting: Hospital-based academic medical center.Patient(s): All IVF cycles from January 2006 through May 2008 having 2PN zygotes that subsequently transitioned to 1PN or 3PN before cleavage, matched to cycles having 2PN zygotes progressing to cleavage without intervening abnormal pronuclear disposition.Intervention(s): Standard IVF protocol.Main Outcome Measure(s): Incidence, day 3 development, and implantation rates of 2PN zygotes transitioning to 1PN and 3PN states before cleavage, compared with normal embryos. Result(s): The incidences of 1PN and 3PN zygotes were 2.9% and 0.4%, respectively. Both types of abnormal zygote showed slower day 3 cleavage, although only the 1PNs exhibited higher fragmentation and asymmetry compared with controls. The 1PN zygotes had a 6.4% implantation rate and viable pregnancy rate of 1.3%. Of the nine 3PN zygotes transferred, none implanted.Conclusion(s): Two-pronuclear zygotes transitioning through 1PN or 3PN states tend to develop into poorer-quality embryos than 2PN control zygotes. Patients should be counseled regarding the very low likelihood of viable pregnancy after transfer of these abnormally developing zygotes. (Fertil Steril (R) 2010; 94: 965-70. (c) 2010 by American Society for Reproductive Medicine.)

With improvements in implantation potential, and the compelling need to reduce the likelihood of multiple pregnancies resulting from in vitro fertilization (IVF), efforts have continued to focus on developing methods to select the most competent embryo for transfer. For the first 15 years or so of human IVF, embryo selection methodologies exclusively involved morphological assessment of the embryo at a single time-point, immediately prior to transfer. Despite considerable efforts to define those characteristics predictive of high implantation potential, the implantation rate of selected embryos is typically only around 30%. More recent attempts to improve selection have assessed characteristics of the oocyte along with those of the embryo at specific times during culture in order to derive a cumulative score. However, these studies have led to conflicting results regarding the worth of cumulative scoring. These conflicting results are likely associated with various study limitations including small sample sizes, a preponderance of retrospective studies combined with variation in timing of evaluations and, in some cases, the use of transfer cohorts in which not all embryos have known implantation fate. While culture to the blastocyst stage has been used in attempts to improve selection, this approach is beneficial for only selected, good prognosis patients, and it is unlikely that even the best current culture media precisely mimic the uterine environment.Given the accepted limitations of morphological approaches, alternative selection methodologies are under development involving targeted analyses or profiling approaches. Targeted analyses involve quantification of known markers in the medium. While these analyses hold some promise, technologies are either cumbersome with turnaround times too long for prospective application, and/or have relatively low predictive value. Of greater potential, metabolomic profiling using spectroscopic analyses of spent media have rapid turnaround, require very small volumes of medium for analysis and may provide superior selection as compared with morphological assessment alone.While we still depend on morphological assessment as our first line approach to embryo selection, it is likely that this may be used in conjunction with metabolomic profiling in the future. As we continue to strive towards identifying the single most competent embryo in any cohort, the aim will be to interface such technologies with the cutting-edge areas of genomic and proteomics research. These are exciting times in the field of IVF, and much future research is required to fine-tune these promising technologies.

In this retrospective case series with historic control subjects, repeat administration of hCG after failure to retrieve oocytes from the first ovary in the setting of unexpectedly low serum hCG levels resulted in unsuccessful IVF outcomes. This represents the largest case series to date regarding repeat administration of hCG in so-called "false" empty follicle syndrome cycles and indicates that patients should be counseled regarding the low likelihood of cycle success after repeat administration of hCG in this setting. (Fertil Steril(R) 2010; 94: 375-7. (C) 2010 by American Society for Reproductive Medicine.)

In a selected group of patients with >20% oocyte immaturity during an IVF cycle with FSH alone, the addition of hMG to the stimulation protocol results in a higher yield of mature oocytes and excellent-quality embryos.

OBJECTIVE: There is no consensus on optimum time for freezing pronucleate stage embryos (2PN's). Additionally, little is known regarding any possible adverse effects of long-term storage on implantation potential. Given the dynamic events that occur during syngamy, time-related sensitivities to freezing may exist and may differ for IVF and ICSI 2PN's. The present study was designed to test the hypotheses that: 1) survival and quality of frozen 2PN's is affected by time interval between insemination (IVF) or ICSI and freezing; and 2) that shorter storage time improves 2PN survival and implantation potential. DESIGN: Retrospective cohort study at our academic center. MATERIALS AND METHODS: Autologous cycles were included that resulted in a 2PN freeze-all from 1/1998 through 5/2007 with at least one subsequent cycle in which some of these frozen 2PN's were thawed and transferred on day 3 (CET; n=282; mean age at retrieval: 34.2±4.1y). 2PN's were frozen between 15-25 h post-IVF or ICSI, using Leibo's standard slow freezing and thaw protocol. Since ICSI results in earlier PN formation, cycles were stratified and analysed by type (IVF, n=174; ICSI, n=108). Linear regression analyses were performed to assess the association between time of freezing (i.e. time interval between IVF/ICSI and freeze) and 2PN survival, implantation rate and live-birth rate. Interaction between time to freeze and storage was also investigated. Wald p-values are two-sided. RESULTS: No significant associations were identified for either IVF or ICSI cycles between time of freezing or any of the outcome variables (overall %survival: 86.0±17.4, mean±SD, implantation rate: 20.2%, live birth rate: 39.7%). Similarly, there were no associations between duration of storage and any of these outcome variables. There was also no interaction between time of freezing and duration of storage (range from 0.05 to 6.27 y) for either IVF or ICSI. The only significant observation was an inverse relation between storage time and the number of transferred embryos having at least 6-cells (p=0.03). CONCLUSIONS: Our data show that time of freezing for IVF or ICSI zygotes does not affect survival, implantation or live birth rates. Furthermore, storage of zygotes (at least up to 6.27y) does not affect clinical outcome even when time interval between IVF/ICSI and freeze was considered. Our observation that quality of IVF embryos decreased with increasing years of storage warrants further investigation.

OBJECTIVE: Identifiers for IVF success are particularly important in patients ≥ 40yo since IVF efficiency is very low in this population. In states where IVF coverage is mandated, insurance companies use day 3 (d3) Follicle Stimulating Hormone (FSH) cut-offs for determining approvals in older patients (< 15.0 mIU/ml for 40 and 41yo, and < 12.0 mIU/ml for 42yo). However, it is unknown whether these exclusions are reasonable. In the present study, we tested the hypothesis that in older patients, FSH may not predict IVF success rates. DESIGN: Retrospective chart review at a university-based IVF center. MATERIALS AND METHODS: Between Jan 1998 and Dec 2006 a total of 2401 autologous IVF (± ICSI) cycles were performed in women 40-45yo. Patients were stratified according to age and then subdivided according to their d3 FSH level as mandated by the insurance industry. Controlled ovarian stimulation was performed with the down-regulation, antagonist, or microflare protocol, using either recombinant FSH or hMG alone or together. Outcome measures included cancellation, implantation (sacs at ≥ 5 weeks) and delivery rates. Statistical analyses were performed with ANOVA, Kruskal Wallis, Chi-square, Fisher's exact tests as appropriate; p<0.05 considered significant. RESULTS: Results are reported in Table 1, Table 2. Cancellation rate was significantly higher only in patients with ≥12 mIU/ml FSH compared with <12 mIU/ml FSH in 42 yo (p<0.001). Neither implantation nor delivery rates were significantly different between any of the FSH cut-offs for any age group (p> 0.05). As expected, a significant decrease in implantation and delivery rates was observed as age increased (p<0.001).Table 1Outcome Variables According to d3 FSHAged3 FSHn% CancelledIR% Delivered/Start40< 157598.712.621.240≥ 152020.013.71541< 157315.19.917.841≥ 15147.15.37.142< 125395.57.013.242≥ 125422.2∗7.07.443< 122105.24.89.043≥ 122010.03.65.0≥ 44< 12432.34.47.0≥ 44≥ 124000∗P < 0.001. Open table in a new tab Table 2Outcomes vs AgeAge40414243≥ 44P ValueIR12.79.87.04.84.4< 0.001% Delivered/Start21.117.612.68.76.4< 0.001 Open table in a new tab ∗P < 0.001. CONCLUSIONS: The present data support our hypothesis that d3 FSH is not predictive of IVF success rates in older patients. Therefore, insurance companies should reconsider their policies regarding use of day 3 FSH when older patients are evaluated for approval.

OBJECTIVE: To test the hypothesis that increased endometrial thickness at baseline compromises clinical IVF success rates. DESIGN: Retrospective cohort study of fresh cycles of IVF or ICSI with day 3 embryo transfer. MATERIALS AND METHODS: All fresh non-donor IVF and ICSI cycles using a down-regulated protocol with day 3 embryo transfer performed at our institution in 2005 and 2006 were reviewed for inclusion. Patients who had a transvaginal ultrasound performed at baseline and who did not have uterine factor infertility or uterine anomalies were included in the study (n=1443). Each patient had only one cycle included in the final dataset (n=1098 cycles). Patients were started on oral contraceptive pills and/or a GnRH agonist for down-regulation. Baseline endometrial thickness (mm) was measured by transvaginal ultrasound after completion of down-regulation. If patients were adequately suppressed (estrogen level < 30 pg/mL), patients were started on rFSH, hMG, or both. hCG was given when ≥ 2 follicles had a mean diameter of ≥18 mm. Endometrial thickness was measured again on the day of hCG administration. Oocyte retrieval and insemination via IVF or ICSI was performed, with assisted hatching performed on selected embryos. Embryo transfer was performed on day 3. Multivariable logistic and linear regression analyses were performed to assess the association of endometrial thickness at baseline or at hCG administration with implantation rate, early loss rate, and live birth rate. Wald p-values are two-sided. RESULTS: Mean patient age was 35.6 years and mean attempt number was 1.5. Mean endometrial thickness at baseline was 5.0 mm (SD 2.3, range 0.6-16.8 mm). Mean thickness at hCG was 11.5 mm (SD 2.6, range 1.1-21.9 mm). Baseline endometrial thickness was inversely associated with both implantation and live birth rates; for every millimeter increase in baseline endometrial thickness, the implantation rate decreased by 1.1% (p=0.02) and the live birth rate decreased by 6% (p=0.03). However, baseline endometrial thickness was not associated with early loss rate. Of note, endometrial thickness on the day of hCG administration was not associated with any of the evaluated IVF outcomes. CONCLUSIONS: The present data support the hypothesis that increased baseline endometrial thickness is negatively associated with IVF outcome. However, the results failed to show an association between endometrial thickness on the day of hCG and clinical IVF success rates.

In this retrospective, matched-paired study, yeast in the embryo culture medium was associated with a trend toward decreased developmental competency that was more pronounced when observed early in culture. Because live births occurred after transfer of embryos in the yeast-contaminated group, we concluded that yeast contamination is not a reason to cancel embryo transfer (ET).

In the patient at risk for ovarian hyperstimulation syndrome, coasting will result in fewer eggs retrieved and embryos produced when compared with cryopreservation of all embryos. However, both strategies are associated with a similar incidence of ovarian hyperstimulation syndrome, with achievement of comparable cumulative pregnancy rates.

Objective: To test the hypothesis that intracytoplasmic sperm injection (ICSI) overcomes a high incidence of tripronucleate zygotes resulting from standard insemination in a previous cycle.Design: A retrospective analysis of matched-pair cycles.Setting: Assisted reproductive technologies (ART) program of Brigham and Women's Hospital.Patient(s): Ninety-five patients with a >= 20% incidence of tripronucleate zygotes in an IVF cycle with use of ICSI in a subsequent attempt.Intervention(s): Cycles with either standard insemination or ICSI.Main Outcome Measure(s): Incidence of diploid (2pn) and triploid (3pn) zygotes and number and quality of embryos obtained.Result(s): Patient age, ampules of gonadotropin used, peak E-2 number of follicles at hCG trigger, and total number of oocytes were all significantly higher in the ICSI cycles, but the number of mature oocytes did not differ. After ICSI. the percentage of 2pn was higher (65.0% vs. 34.1%), and the percentage of 3pn was lower (5.0% vs. 33.9%) than after IVF, and more diploid embryos were obtained with ICSI (5.5 +/- 3.7 vs. 3.4 +/- 2.2 [mean +/- SD]). There was no difference in embryo quality between, the two groups:Conclusion(s): ICSI appears beneficial in women with a high 3pn occurrence IVF because it increases the number of diploid zygotes without affecting embryo quality.

OBJECTIVE:To determine whether day 3 embryos exhibiting early compaction have an improved implantation potential compared to embryos without compaction. DESIGN:A retrospective cohort study. SETTING:Hospital-based academic medical center. PATIENT(S):Women <38 years of age undergoing IVF cycles between November 2001 and December 2004 having a day 3 transfer of one or two embryos with >8 cells. INTERVENTION(S):Standard IVF protocol. MAIN OUTCOME MEASURE(S):Compaction grading and implantation rates of 1,047 embryos as related to fragmentation of >or= 8-cell embryos in patients with either 0% or 100% implantation. RESULT(S):Compaction grading was strongly associated with implantation potential; however, the direction of this effect depended on the degree of fragmentation. In embryos with <10% fragmentation, implantation rates increased with the degree of compaction (grade 1, 25%; grade 2, 33%; and grade 3, 47%); in embryos with >or=10% fragmentation, the effect was reversed (grade 1, 38%; grade 2, 20%; and grade 3, 9%). CONCLUSION(S):Assessing the degree of compaction can be a valuable addition to traditional morphologic assessment in identifying optimal embryos for transfer on day 3.

To determine whether the addition of hMG to FSH in a controlled ovarian stimulation (COS) protocol increases the yield of mature oocytes in patients with a history of high rates of oocyte immaturity. Retrospective matched cohort study. All cycles performed between January 2000 and March 2005 at a large academic practice were reviewed. To be included for analysis, patient had to have undergone COS with recombinant FSH alone in a non-pregnancy cycle with a yield of >20% oocyte immaturity (FSH Alone Group). In addition, these patients had to have undergone a subsequent cycle in which hMG was added to FSH in the stimulation protocol (FSH/hMG Group). Thus, each patient served as her own control. Cycle pairs were excluded if they were discordant for ICSI/Non-ICSI. A total of 110 cycle pairs were identified. Cycle characteristics and outcomes were compared. Excellent quality embryos were defined as having at least 8-cells with < 10% fragmentation. Data were analyzed using the non-parametric Wilcoxon Signed Rank test for matched pairs, with p< 0.05 considered statistically significant. The mean patient age was 35.3+/-3.95. Tabled 1 According to the two-cell theory of follicular development, both LH and FSH play a role in the development of a mature follicle. Nevertheless, the relative merit of adding hMG to FSH in COS continues to be debated. Using a matched pair analysis for a cohort of patients with previous high rates of oocyte immaturity, we demonstrate that addition of hMG to FSH in COS is beneficial, as reflected by an increased yield of both mature oocytes and excellent quality embryos obtained.

ObjectiveIn high responding patients undergoing gonadotropin/IUI treatment, conversion to in vitro fertilization (IVF) is a popular alternative to cycle cancellation. Such an approach allows a chance of pregnancy while controlling the number of embryos that might implant. Although such conversions have resulted in high pregnancy rates following day 3 embryo transfers (ET), it is unknown whether outcomes are compromised following day 5 ET. The present study was performed to investigate this question by comparing pregnancy rates following day 5 ET in converted gonadotropin/IUI cycles (IUI-IVF Group) with those of non-IUI converted cycles (IVF Group).DesignA matched pair analysis of day 5 ET IVF cycles performed at a large hospital-based IVF clinic.Materials and methodsA retrospective analysis was performed of all day 5 ETs resulting either from gonadotropin/IUI cycles converted to IVF (n=35), or from standard first attempt Day 5 IVF cycles (n=316), that were conducted between May, 1998 and December, 2004. The 35 patients in the IUI/IVF Group were matched to patients who underwent day 5-ET with their first IVF cycle (IVF Group) by the following criteria: age, number of mature eggs, number of embryos and number of embryos with ≥ 8-cells on day 3. Comparisons between the IVF and IUI/IVF Groups for total number of blastocysts, number of expanding/expanded blastocysts, and number of expanding/expanded blastocysts that were transferred. In addition, implantation rates (number of fetal hearts/number of embryos transferred) and clinical pregnancy and ongoing-delivered rates were calculated, and the number of embryos frozen determined. Data were analyzed by the non-parametric Wilcoxon Signed Rank test for matched pairs, and Chi square and Fisher's exact test, as appropriate, with p<0.05 considered statistically significant.ResultsTabled 1ConclusionThese data show that blastocyst conversion rates and quality of blastocysts, in addition to clinical and ongoing pregnancy rates, implantation rates and the number of embryos frozen, were comparable in gonadotropin/IUI cycles converted to IVF as compared with standard IVF cycles. Therefore, high responding patients undergoing conversion to IVF cycles may be safely taken to day 5 transfer without risk of compromising their likelihood of a successful clinical outcome. ObjectiveIn high responding patients undergoing gonadotropin/IUI treatment, conversion to in vitro fertilization (IVF) is a popular alternative to cycle cancellation. Such an approach allows a chance of pregnancy while controlling the number of embryos that might implant. Although such conversions have resulted in high pregnancy rates following day 3 embryo transfers (ET), it is unknown whether outcomes are compromised following day 5 ET. The present study was performed to investigate this question by comparing pregnancy rates following day 5 ET in converted gonadotropin/IUI cycles (IUI-IVF Group) with those of non-IUI converted cycles (IVF Group). In high responding patients undergoing gonadotropin/IUI treatment, conversion to in vitro fertilization (IVF) is a popular alternative to cycle cancellation. Such an approach allows a chance of pregnancy while controlling the number of embryos that might implant. Although such conversions have resulted in high pregnancy rates following day 3 embryo transfers (ET), it is unknown whether outcomes are compromised following day 5 ET. The present study was performed to investigate this question by comparing pregnancy rates following day 5 ET in converted gonadotropin/IUI cycles (IUI-IVF Group) with those of non-IUI converted cycles (IVF Group). DesignA matched pair analysis of day 5 ET IVF cycles performed at a large hospital-based IVF clinic. A matched pair analysis of day 5 ET IVF cycles performed at a large hospital-based IVF clinic. Materials and methodsA retrospective analysis was performed of all day 5 ETs resulting either from gonadotropin/IUI cycles converted to IVF (n=35), or from standard first attempt Day 5 IVF cycles (n=316), that were conducted between May, 1998 and December, 2004. The 35 patients in the IUI/IVF Group were matched to patients who underwent day 5-ET with their first IVF cycle (IVF Group) by the following criteria: age, number of mature eggs, number of embryos and number of embryos with ≥ 8-cells on day 3. Comparisons between the IVF and IUI/IVF Groups for total number of blastocysts, number of expanding/expanded blastocysts, and number of expanding/expanded blastocysts that were transferred. In addition, implantation rates (number of fetal hearts/number of embryos transferred) and clinical pregnancy and ongoing-delivered rates were calculated, and the number of embryos frozen determined. Data were analyzed by the non-parametric Wilcoxon Signed Rank test for matched pairs, and Chi square and Fisher's exact test, as appropriate, with p<0.05 considered statistically significant. A retrospective analysis was performed of all day 5 ETs resulting either from gonadotropin/IUI cycles converted to IVF (n=35), or from standard first attempt Day 5 IVF cycles (n=316), that were conducted between May, 1998 and December, 2004. The 35 patients in the IUI/IVF Group were matched to patients who underwent day 5-ET with their first IVF cycle (IVF Group) by the following criteria: age, number of mature eggs, number of embryos and number of embryos with ≥ 8-cells on day 3. Comparisons between the IVF and IUI/IVF Groups for total number of blastocysts, number of expanding/expanded blastocysts, and number of expanding/expanded blastocysts that were transferred. In addition, implantation rates (number of fetal hearts/number of embryos transferred) and clinical pregnancy and ongoing-delivered rates were calculated, and the number of embryos frozen determined. Data were analyzed by the non-parametric Wilcoxon Signed Rank test for matched pairs, and Chi square and Fisher's exact test, as appropriate, with p<0.05 considered statistically significant. ResultsTabled 1 ConclusionThese data show that blastocyst conversion rates and quality of blastocysts, in addition to clinical and ongoing pregnancy rates, implantation rates and the number of embryos frozen, were comparable in gonadotropin/IUI cycles converted to IVF as compared with standard IVF cycles. Therefore, high responding patients undergoing conversion to IVF cycles may be safely taken to day 5 transfer without risk of compromising their likelihood of a successful clinical outcome. These data show that blastocyst conversion rates and quality of blastocysts, in addition to clinical and ongoing pregnancy rates, implantation rates and the number of embryos frozen, were comparable in gonadotropin/IUI cycles converted to IVF as compared with standard IVF cycles. Therefore, high responding patients undergoing conversion to IVF cycles may be safely taken to day 5 transfer without risk of compromising their likelihood of a successful clinical outcome.

Numerous studies have shown that embryo morphology plays a key role in IVF outcome. Development to at least the 8-cell stage has been correlated with improved implantation potential, thereby providing a potentially useful marker for evaluating laboratory performance. However, it is essential to identify what variables impact embryo cleavage when using this type of marker for quality assessment so that relevant target values are identified for each technique being assessed. This study was undertaken to test the hypothesis that culture media type and patient age both influence development of the embryo to at least the 8-cell stage and therefore must be taken into consideration when assessing laboratory performance using ≥ 8-cell embryos as a marker. Retrospective data analysis. 7,030 ART cycles performed in our institution from January 1, 1998 to December 31, 2003 were retrospectively reviewed. The study dataset included 3,678 IVF cycles with or without assisted hatching. Oocytes were inseminated in Ham's F10+5% HSA or 10% SSS and evaluated 16–18 hr later for PN formation. Diploid zygotes were then transferred to one of the following culture media: a) Vitro Life Series: IVF500, n=4,248; G1.2, n=7,323; G1.3, n=5,329; or b) Irvine Scientific: P1, n=10,805. Embryos were stratified according to growth medium used and patient age (<35y and ≥35y), and evaluated for development to the ≥ 8-cell stage. Data were analyzed using Chi square with p<0.05 considered statistically significant. Media type significantly impacted development of embryos to ≥ 8-cell stage (IVF500: 27.7%; G1.2: 34.7%; G1.3: 38.7%; P1: 43.3%; p<0.0001). Of note, there was a significant improvement in the % of embryos at ≥8-cells as each new generation of Vitro Life medium was introduced (p<0.0001). As shown in the table, within age group, medium type continued to impact development to at least the 8-cell stage (p<0.0001 for both age groups). However, this impact was not consistently observed within across age groups and within medium. Our data indicate that cleavage rate is influenced by patient age and culture medium type. This relationship should be taken into consideration when establishing quality assurance target values. For example, our current day 5 inclusion criteria were developed using the IVF500 system. Given our current medium system (G1.3) and the results of this analysis, we must now revise our Day 5 inclusion criteria because the relevant target values have changed. Constant surveillance of relevant target values must be maintained in the IVF laboratory since improvements are continually being made in ART systems as demonstrated by the improvement across the generations of Vitro Life media.

Objective: Obstructive and nonobstructive azoospermia accounts for a relatively high incidence of male factor infertility. These patients require epididymal aspirations and/or testicular biopsies performed either the day of egg retrieval or prior to cycle start. This study investigated impact of sperm preparation conditions, source, and diagnosis on IVF outcome. Design: Retrospective analysis of patients undergoing ICSI with fresh or frozen testicular or epididymal sperm at Brigham and Women's Hospital, Boston, MA from 1998–2002. Materials and Methods: 141 ICSI cycles from 84 patients were identified that had utilized fresh or frozen testicular or epididymal sperm. Embryo quality (i.e. % ≥ 8 cells with <10 fragments), implantation, and ongoing pregnancy rates were assessed with respect to time of sperm harvest (fresh or frozen), sperm origin, and azoospermia diagnosis (obstructive or nonobstructive). Results were analyzed using Chi-square and Mann-Whitney U tests as appropriate with p< 0.05 considered statistically significant. Results: No statistical difference was found in the ongoing pregnancy rates (50.0% vs 39.5%) or overall embryo quality (21.7% vs 21.3%) between epididymal or testicular sperm regardless of whether it was fresh or frozen. However, there was a significantly increased implantation rate with all fresh sources versus all frozen sources ( 26.1% vs 16.8%, p=0.014). Comparison of obstructive versus non-obstructive azoospermia using testicular specimens showed a significant increase in pregnancy rate, implantation rate, and embryo quality in the obstructive versus non-obstructive patients. Tabled 1 Tabled 1 Conclusion: The use of fresh rather than frozen specimens for ICSI from azoospermic males results in an increased implantation rate but with no concordant increase in pregnancy rates. In addition, testicular specimens from non-obstructed males are associated with poor clinical outcome, reduced implantation rate and poorer embryo quality. Pregnancy rates using ejaculated, epididymal, or obstructive testicular sperm should not be used to counsel patients with non-obstructive azoospermia in terms of their ultimate probability of success.

Controlling multiple pregnancies in patients undergoing artificial reproductive procedures requires consideration of single embryo transfers. Therefore, refinements for embryo evaluation are needed that select for the most developmentally competent embryo. The present study was designed to identify day 3 and day 5 morphological predictors of viability following transfers in which the morphology and fate of each embryo was precisely determined. Assessments on day 3 included cell number, and the extent of fragmentation and asymmetry, and on day 5, the developmental stage. Embryos resulting in a viable fetus at 11 weeks gestation were considered developmentally competent. The relationships among individual and collective embryo morphological characteristics were evaluated. Analysis of the interactions among morphological characteristics of embryos transferred on day 3 enabled identification of a multivariable selection order. Assessment of day 5 embryos revealed that expanding and expanded blastocysts exhibited comparable developmental potential that was superior to that of either morulae or early blastocysts. However, expanding or expanded blastocysts derived from 7-cell or 8-cell embryos were developmentally superior to those derived from other cleavage stages, regardless of fragmentation or asymmetry. Collectively, these findings further understanding of morphological predictors of viability, thereby improving the ability to select the most viable embryo for transfer.