Obesity significantly alters the human sperm proteome, with potential implications for fertility.

PURPOSE: In men, obesity may lead to poor semen parameters and reduced fertility. However, the causative links between obesity and male infertility are not totally clear, particularly on a molecular level. As such, we investigated how obesity modifies the human sperm proteome, to elucidate any important implications for fertility. METHODS: Sperm protein lysates from 5 men per treatment, classified as a healthy weight (body mass index (BMI) ≤ 25 kg/m2) or obese (BMI ≥ 30 kg/m2), were FASP digested, submitted to liquid chromatography tandem mass spectrometry, and compared by label-free quantification. Findings were confirmed for several proteins by qualitative immunofluorescence and a quantitative protein immunoassay. RESULTS: A total of 2034 proteins were confidently identified, with 24 proteins being significantly (p < 0.05) less abundant (fold change < 0.05) in the spermatozoa of obese men and 3 being more abundant (fold change > 1.5) compared with healthy weight controls. Proteins with altered abundance were involved in a variety of biological processes, including oxidative stress (GSS, NDUFS2, JAGN1, USP14, ADH5), inflammation (SUGT1, LTA4H), translation (EIF3F, EIF4A2, CSNK1G1), DNA damage repair (UBEA4), and sperm function (NAPA, RNPEP, BANF2). CONCLUSION: These results suggest that oxidative stress and inflammation are closely tied to reproductive dysfunction in obese men. These processes likely impact protein translation and folding during spermatogenesis, leading to poor sperm function and subfertility. The observation of these changes in obese men with no overt andrological diagnosis further suggests that traditional clinical semen assessments fail to detect important biochemical changes in spermatozoa which may compromise fertility.

Infertility patients with chromosome inversions are not susceptible to an inter-chromosomal effect.

PURPOSE: The aim of this study was to evaluate the incidence of an inter-chromosomal effect (ICE) in blastocyst-stage embryos from carriers of balanced chromosome inversions. METHODS: Infertility patients (n = 52) with balanced inversions (n = 66 cycles), and maternal age-matched controls that concurrently cycled (n = 66), consented to an IVF cycle with preimplantation genetic testing for aneuploidy (PGT-A). Blastocyst-stage embryos underwent trophectoderm biopsy for PGT-A with only euploid blastocysts transferred in a subsequent frozen embryo transfer. Subtypes of inversions were included in aggregate: paracentric/pericentric, polymorphic/non-polymorphic, male/female carriers, and varying inversion sizes. RESULTS: The incidence of aneuploidy was not significantly higher for the inversion patients compared to the controls (inversion = 48.8% vs. control = 47.2% ns). Following euploid blastocyst transfer, there were excellent live birth outcomes. CONCLUSIONS: Carriers of balanced chromosome inversions did not exhibit higher aneuploidy rates for chromosomes that were not involved in the inversion compared to maternal age-matched controls, signifying the absence of an inter-chromosomal effect for this data set. These results provide the largest investigation of blastocyst embryos regarding the debated existence of an ICE resulting from the presence of an inversion during meiosis. However, further studies are warranted to investigate an ICE among inversions subtypes that were outside the scope of this study.

Differing molecular response of young and advanced maternal age human oocytes to IVM.

STUDY QUESTION: What effect does maternal age have on the human oocyte's molecular response to in vitro oocyte maturation? SUMMARY ANSWER: Although polyadenylated transcript abundance is similar between young and advanced maternal age (AMA) germinal vesicle (GV) oocytes, metaphase II (MII) oocytes exhibit a divergent transcriptome resulting from a differential response to in vitro oocyte maturation. WHAT IS KNOWN ALREADY: Microarray studies considering maternal age or maturation stage have shown that either of these factors will affect oocyte polyadenylated transcript abundance in human oocytes. However, studies considering both human oocyte age and multiple stages simultaneously are limited to a single study that examined transcript levels for two genes by qPCR. Thus, polyadenylated RNA sequencing (RNA-Seq) could provide novel insight into age-associated aberrations in gene expression in GV and MII oocytes. STUDY DESIGN, SIZE, DURATION: The effect of maternal age (longitudinal analysis) on polyadenylated transcript abundance at different stages was analyzed by examining single GV and single in vitro matured MII oocytes derived from five young (YNG; < 30 years; average age 26.8; range 20-29) and five advanced maternal age (AMA; ≥40 years; average age 41.6 years; range 40-43 years) patients. Thus, a total of 10 YNG (5 GV and 5 MII) and 10 AMA (5 GV and 5 MII) oocytes were individually processed for RNA-Seq analysis. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Patients undergoing infertility treatment at the Colorado Center for Reproductive Medicine (Lone Tree, CO, USA) underwent ovarian stimulation with FSH and received hCG for final follicular maturation prior to ultrasound guided oocyte retrieval. Unused GV oocytes obtained at retrieval were donated for transcriptome analysis. Single oocytes were stored (at -80°C in PicoPure RNA Extraction Buffer; Thermo Fisher Scientific, USA) immediately upon verification of immaturity or after undergoing in vitro oocyte maturation (24 h incubation), representing GV and MII samples, respectively. After isolating RNA and generating single oocyte RNA-Seq libraries (SMARTer Ultra Low Input RNA HV kit; Clontech, USA), Illumina sequencing (100 bp paired-end reads on HiSeq 2500) and bioinformatics analysis (CLC Genomics Workbench, DESeq2, weighted gene correlation network analysis (WGCNA), Ingenuity Pathway Analysis) were performed. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 12 770 genes were determined to be expressed in human oocytes (reads per kilobase per million mapped reads (RPKM) > 0.4 in at least three of five replicates for a minimum of one sample type). Differential gene expression analysis between YNG and AMA oocytes (within stage) identified 1 and 255 genes that significantly differed (adjusted P < 0.1 and log2 fold change >1) in polyadenylated transcript abundance for GV and MII oocytes, respectively. These genes included CDK1, NLRP5 and PRDX1, which have been reported to affect oocyte developmental potential. Despite the similarity in transcript abundance between GV oocytes irrespective of age, divergent expression patterns emerged during oocyte maturation. These age-specific differentially expressed genes were enriched (FDR < 0.05) for functions and pathways associated with mitochondria, cell cycle and cytoskeleton. Gene modules generated by WGCNA (based on gene expression) and patient traits related to oocyte quality (e.g. age and blastocyst development) were correlated (P < 0.05) and enriched (FDR < 0.05) for functions and pathways associated with oocyte maturation. LARGE SCALE DATA: Raw data from this study can be accessed through GSE95477. LIMITATIONS, REASONS FOR CAUTION: The human oocytes used in the current study were obtained from patients with varying causes of infertility (e.g. decreased oocyte quality and oocyte quality-independent factors), possibly affecting oocyte gene expression. Oocytes in this study were retrieved at the GV stage following hCG administration and the MII oocytes were derived by IVM of patient oocytes. Although the approach has the benefit of identifying intrinsic differences between samples, it may not be completely representative of in vivo matured oocytes. WIDER IMPLICATIONS OF THE FINDINGS: Transcriptome profiles of YNG and AMA oocytes, particularly at the MII stage, suggest that aberrant transcript abundance may contribute to the age-associated decline in fertility. STUDY FUNDING/COMPETING INTEREST(S): J.M.R. was supported by an Austin Eugene Lyons Fellowship awarded by the University of California, Davis. The Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (awarded to P.J.R.; R01HD070044) and the Fertility Laboratories of Colorado partly supported the research presented in this manuscript.

Dysregulation of methylation and expression of imprinted genes in oocytes and reproductive tissues in mice of advanced maternal age.

PURPOSE: To evaluate reproductive outcomes in aged compared to young female mice, and determine associated methylation and expression of imprinted genes in reproductive tissues. METHODS: Fetal, placental, and ovarian tissue were collected on d16.5 of pregnancy from young (4-5 weeks) and aged (15 months) mice. Uterine tissue and in vivo matured oocytes were collected from non-pregnant females. Methylation of imprinted genes was determined by restriction enzyme based assays, and transcript abundance of imprinted and nutrient supply genes were analyzed by quantitative PCR (qPCR). RESULTS: Maternal age was associated with fetal growth restriction and placental overgrowth. In maternally aged mice, methylation was minimally dysregulated in fetal tissue, while placental tissue showed aberrant methylation and transcript abundance of imprinted genes. Ovarian methylation and gene expression was severely dysregulated, although oocyte gene expression was only minimally altered. Abundance of Kcnq1 transcripts was significantly (P < 0.05) increased in oocytes obtained from aged females compared to young females. Gene expression was also severely dysregulated in the uterus, including nutrient transport genes. CONCLUSION: Fetal and placental growth abnormalities correspond to aberrant methylation and gene expression in reproductive tissues from maternally aged mice. Significant alterations in gene expression and methylation in the aged ovary suggests that the follicular environment may be compromised. Aberrant methylation and expression of imprinted genes in the aged uterus may contribute to reduced implantation. Maternal age negatively affects imprinted gene methylation and expression in both germ cells and somatic cells of the reproductive tract, contributing to the reduced fertility observed with advanced maternal age.

Fatty acid metabolism during maturation affects glucose uptake and is essential to oocyte competence.

Fatty acid ß-oxidation (FAO) is essential for oocyte maturation in mice. The objective of this study was to determine the effect of etomoxir (a FAO inhibitor; 100 µM), carnitine (1 mM), and palmitic acid (1 or 100 µM) during maturation on metabolism and gene expression of the oocyte and cumulus cells, and subsequent embryo development in the mouse. Carnitine significantly increased embryo development, while there was a decrease in development following maturation with 100 µM palmitic acid or etomoxir (P<0.05) treatment. Glucose consumption per cumulus-oocyte complex (COC) was decreased after treatment with carnitine and increased following etomoxir treatment (P<0.05). Intracellular oocyte lipid content was decreased after carnitine or etomoxir exposure (P<0.05). Abundance of Slc2a1 (Glut1) was increased after etomoxir treatment in the oocyte and cumulus cells (P<0.05), suggesting stimulation of glucose transport and potentially the glycolytic pathway for energy production when FAO is inhibited. Abundance of carnitine palmitoyltransferase 2 (Cpt2) tended to increase in oocytes (P=0.1) after treatment with 100 µM palmitic acid and in cumulus cells after exposure to 1 µM palmitic acid (P=0.07). Combined with carnitine, 1 µM palmitic acid increased the abundance of Acsl3 (P<0.05) and Cpt2 tended to increase (P=0.07) in cumulus cells, suggesting FAO was increased during maturation in response to stimulators and fatty acids. In conclusion, fatty acid and glucose metabolism are related to the mouse COC, as inhibition of FAO increases glucose consumption. Stimulation of FAO decreases glucose consumption and lipid stores, positively affecting subsequent embryo development, while an overabundance of fatty acid or reduced FAO negatively affects oocyte quality.

Embryos whose polar bodies contain isolated reciprocal chromosome aneuploidy are almost always euploid.

STUDY QUESTION: When a chromosome aneuploidy is detected in the first polar body and a reciprocal loss or gain of the same chromosome is detected in the second polar body, is the resulting embryo usually aneuploid for that chromosome? SUMMARY ANSWER: When reciprocal aneuploidy occurs in polar bodies, the resulting embryo is usually normal for that chromosome, indicating that premature separation of sister chromatids (PSSC)-not non-disjunction-likely occurred in meiosis I. WHAT IS KNOWN ALREADY: Single-nucleotide polymorphism-based microarray analysis can be used to accurately determine the chromosomal status of polar bodies and embryos. Sometimes, the only abnormality found is a reciprocal gain or loss of one or two chromosomes in the two polar bodies. Prediction of the status of the resulting embryo in these cases is problematic. STUDY DESIGN, SIZE, DURATION: Blinded microarray analysis of previously diagnosed aneuploid embryos that had reciprocal polar body aneuploidy. MATERIALS, SETTING, METHODS: IVF cycles were performed between 2008 and 2011 in patients aged 40 ± 3 years (range 35-47 years) with an indication for polar body-based aneuploidy screening. Thirty-five aneuploid vitrified Day 3 embryos were warmed, cultured to Day 5 and biopsied for microarray analysis. Predictions were made for the ploidy status of the embryo if PSSC or non-disjunction had occurred. The signal intensity for the aneuploid chromosome in the first polar body was compared between those that resulted in euploid and aneuploid embryos. MAIN RESULTS AND THE ROLE OF CHANCE: Among 34 embryos with evaluable results, 31 were euploid on re-analysis. Of 43 chromosomes that had reciprocal aneuploidy in the polar bodies, 41 were disomic in the embryo, indicating that PSSC was likely to have occurred 95% (95% confidence interval 85-99%) of the time. The log 2 ratio signal intensity from the chromosomes that underwent non-disjunction, resulting in unbalanced embryos, were outliers when compared with those that underwent PSSC. LIMITATIONS, REASONS FOR CAUTION: Although most embryos with reciprocal aneuploid polar bodies were euploid, it is unknown whether they maintain equivalent reproductive potential when transferred. Further study is needed to determine whether these embryos should be re-biopsied and considered for transfer. WIDER IMPLICATIONS OF THE FINDINGS: This study is consistent with increasing evidence that PSSC is the primary cause of meiosis I errors in embryos from women of advanced reproductive age. Clinicians should be cautious in interpreting results from polar body aneuploidy screening, especially when only the first polar body is tested.

Human and mouse embryonic development, metabolism and gene expression are altered by an ammonium gradient in vitro.

Ammonium is generated in culture media by the spontaneous deamination of amino acids at 37 °C and through the metabolism of amino acids by human embryos. The appearance of ammonium is a time-dependent phenomenon and can compromise embryo physiology, development and viability. In this study, the effects of a gradient of ammonium on the development, metabolism and transcriptome of human and mouse embryos were investigated. Pronucleate oocytes were cultured in the presence of an ammonium gradient that mimicked the spontaneous deamination of Eagle's amino acids together with 1 mM glutamine. All embryos were cultured in sequential media G1/G2 at 5% O2, 6% CO2 and 89% N2. Human embryo metabolism was assessed through a non-invasive fluorometric analysis of pyruvate consumption. Transcriptome analysis was performed on the resultant blastocysts from both species using a microarray technology. Embryo development prior to compaction was negatively affected by the presence of low levels of ammonium in both species. Human embryo metabolism was significantly inhibited after just 24 and 48 h of culture. Transcriptome analysis of blastocysts from both species revealed significantly altered gene expression profiles, both decreased and increased. Functional annotation of the altered genes revealed the following over represented biological processes: metabolism, cell growth and/or maintenance, transcription, cell communication, transport, development and transcription regulation. These data emphasize the enhanced sensitivity of the cleavage-stage embryo to its environment and highlight the requirement to renew culture media at frequent intervals in order to alleviate the in vitro induced effects of ammonium build-up in the environment surrounding the embryo.

Blastocysts from patients with polycystic ovaries exhibit altered transcriptome and secretome.

Polycystic ovaries (PCO) is a common phenotype of women presenting for infertility treatment. This study investigated whether blastocysts derived from women with PCO have an altered molecular signature which could be a causative factor contributing to reproductive failure. Morphologically similar blastocysts derived from women with PCO and donor oocyte cycles were analysed for transcription and protein secretion. Unsupervised hierarchical clustering demonstrated that the transcriptome profiles of blastocysts derived from PCO patients and control blastocysts were markedly different with complete branch separation. Statistical analysis revealed 829 genes with significantly different expression: 784 decreased (94.6%) and 45 increased (5.4%) in blastocysts derived from women with PCO compared with controls (P<0.05). Functional annotation of these genes revealed predominant gene ontology biological processes including protein metabolism (30%), transcription (22%), signal transduction (15%), biosynthesis (15%) and cell cycle (14%). Proteomic profiling identified 12 biomarkers that displayed significant decrease in expression in blastocysts derived from women with PCO compared with controls (P<0.05). These data indicate molecular alterations in human blastocysts derived from PCO patients, potentially demonstrating for the first time a link between patient aetiology/phenotype and subsequent embryo development, which in part may explain the observed reduction in reproductive capacity.

The role of proteomics in defining the human embryonic secretome.

Non-invasive gamete and embryo assessment is considered an important focus in assisted reproductive technologies (ART). Currently, the selection of embryos for transfer is based on morphological indices. Though successful, the field of ART would benefit from a non-invasive quantitative method of viability determination. Omics technologies, including transcriptomics, proteomics and metabolomics, have already begun providing evidence that viable gametes and embryos possess unique molecular profiles with potential biomarkers that can be utilized for developmental and/or viability selection. Unlike the human genome that is relatively fixed and steady throughout the human body, the human proteome, estimated at over a million proteins, is more complex, diverse and dynamic. It is the proteins themselves that contribute to the physiological homeostasis in any cell or tissue. Of particular interest in ART is the secretome, those proteins that are produced within the embryo and secreted into the surrounding environment. Defining the human embryonic secretome has the potential to expand our knowledge of embryonic cellular processes, including the complex dialogue between the developing embryo and its maternal environment, and may also assist in identifying those embryos with the highest implantation potential. Advances in proteomic technologies have allowed the non-invasive profiling of the human embryonic secretome with ongoing research focused on correlation with outcome. From a clinical perspective, embryo selection based on morphological assessment and non-invasive analysis of the human embryonic secretome may improve IVF success and lead to routine single embryo transfers.

Comprehensive molecular cytogenetic analysis of the human blastocyst stage.

BACKGROUND: The high frequency of chromosomal abnormalities observed in human gametes and embryos is unlike that seen in other mammalian species and is of great clinical significance, leading to high rates of pregnancy loss, and live-born children with aneuploid syndromes. Although much is known concerning the aneuploidy rates of oocytes, cleavage stage embryos and fetuses during pregnancy, the chromosomal status of blastocysts has been relatively little investigated. METHODS: A total of 158 good quality blastocysts were examined using micromanipulation, whole genome amplification and comparative genomic hybridization. RESULTS: From the obtained data, it was evident that the aneuploidy rate (38.8%) is significantly lower for blastocysts than for embryos at earlier stages (51%). However, in many cases, chromosome errors, including monosomy, imbalance affecting the larger chromosomes and complex aneuploidy persisted to this final stage of preimplantation development. CONCLUSIONS: This study represents the first attempt to gain a detailed insight into the extent and type of chromosome errors seen at the blastocyst stage, using a comprehensive molecular cytogenetic method. Our data suggest that the blastocyst stage does not represent an absolute selective barrier, and that the majority of aneuploid embryos are lost at the time of implantation or shortly thereafter.

Blastocyst versus day 2 or 3 transfer.

The formulation of new sequential culture media, capable of supporting the development of viable human blastocysts, has reopened the discussion regarding the best day for embryo transfer following in vitro fertilization (IVF). Although several laboratories have reported overall increases in implantation rate and IVF efficiency following the transfer of blastocysts, others have failed to observe any benefit from extended culture. While culture conditions for the mammalian embryo undoubtedly have improved significantly over the past few years, relatively little attention has been paid to the quality of oocytes derived from ovarian hyperstimulation or the quality and receptivity of the endometrium following such hormonal regimes. It appears that differences in controlled ovarian hyperstimulation are among the major factors determining embryo quality and subsequent implantation. This therefore has confounded comparisons between different laboratories. In spite of this there are a growing number of reports demonstrating that the advantages of extended culture and blastocyst transfer, such as increased implantation rates, are not limited to specific groups of patients or specific etiologies. Rather, blastocyst transfer may be of benefit to the majority if not all patients attending for IVF.

Blastocyst culture and transfer increases the efficiency of oocyte donation.

OBJECTIVE: To determine the impact of blastocyst transfer on an oocyte donation program. DESIGN: Retrospective review of embryo transfer in an IVF clinic. SETTING: Private assisted reproductive technology unit. PATIENT(S): Two hundred and twenty nine patients undergoing oocyte donation. INTERVENTION(S): Culture of pronucleate embryos to either day 3 or day 5 followed by embryo transfer. MAIN OUTCOME MEASURE(S): Implantation rates, pregnancy rates, and multiple gestations were analyzed. RESULT(S): Implantation rates and pregnancy rates were significantly increased by moving to extended embryo culture and transfer on day 5. After day 3 transfers, implantation and pregnancy rates were 47.1% and 75%, respectively. In contrast, on day 5 these rates were increased to 65.8% and 87.6%. Concomitantly, there were significantly fewer embryos transferred on day 5 (2.1) compared to day 3 (3.2). CONCLUSION(S): Blastocyst transfer is a highly effective treatment for patients who receive donor oocytes, allowing excellent pregnancy rates while significantly reducing the incidence of high-order multiple gestations.

Evaluating strategies for improving ovarian response of the poor responder undergoing assisted reproductive techniques.

OBJECTIVE: To assess the efficacy of various controlled ovarian hyperstimulation (COH) regimens in the prior poor-responder patient preparing for assisted reproductive techniques. DESIGN: English-language literature review. PATIENT(S): Candidates for assisted reproductive techniques who had been defined as having a prior suboptimal response to standard COH regimens. INTERVENTION(S): A variety of regimes are reviewed, including increased gonadotropin doses, change of gonadotropins, adjunctive growth hormone (GH), luteal phase (long) GnRH agonist (GnRH-a) initiation, early follicular phase (flare) GnRH-a initiation, low-dose luteal phase (ultrashort) GnRH-a initiation, progestin pretreatment, and microdose flare GnRH-a initiation. MAIN OUTCOME MEASURE(S): Maximal serum E(2) levels, follicular development, dose, and duration of gonadotropin therapy, cycle cancellation rates, oocytes retrieved, embryos transferred, and clinical and ongoing pregnancy rates. RESULT(S): A lack of uniformity in definition of the poor responder and of prospective randomized trials make data interpretation somewhat difficult. Of the varied strategies proposed, those that seem to be more uniformly beneficial are microdose GnRH-a flare and late luteal phase initiation of a short course of low-dose GnRH-a discontinued before COH. CONCLUSION(S): No single regimen will benefit all poor responders. General acceptance of uniform definitions and performance of large-scale prospective randomized trials are critical. Development of a reliable precycle screen will allow effective differentiation among normal responders, poor responders, and those who will not conceive with their own oocytes.

Laparoscopic management of hydrosalpinges before in vitro fertilization-embryo transfer: salpingectomy versus proximal tubal occlusion.

OBJECTIVE: To compare ovarian response and IVF-ET cycle outcome in patients with hydrosalpinges managed by either laparoscopic salpingectomy or proximal tubal occlusion. DESIGN: Retrospective analysis. SETTING: Tertiary-care assisted reproductive technology program. PATIENT(S): One hundred four consecutive fresh IVF-ET cycles in 94 patients with tubal-factor infertility. INTERVENTION(S): Laparoscopic salpingectomy (group 1: 35 cycles) or bipolar proximal tubal occlusion (group 2: 17 cycles), controlled ovarian hyperstimulation, and IVF-ET. Control groups consisted of both tubal-factor patients without hydrosalpinges (group 3: 37 cycles) and those with prior bilateral tubal ligation for sterilization (group 4: 15 cycles). MAIN OUTCOME MEASURE(S): Uterine artery Doppler flow, controlled ovarian hyperstimulation response, and implantation and clinical pregnancy rates. RESULT(S): There were no differences in mean uterine artery pulsatility indices or ovarian response among any of the groups. A trend toward a higher cycle cancellation rate in group 1 did not approach statistical significance. Clinical pregnancy and implantation rates were not significantly different between group 1 (57.1%, 29.2 +/- 5.9%, respectively) and group 2 (46.7%, 19.4 +/- 6.1%, respectively) or compared with those of controls. CONCLUSION(S): [1] Management of hydrosalpinges by laparoscopic salpingectomy or bipolar proximal tubal occlusion yielded statistically similar responses to controlled ovarian hyperstimulation and IVF-ET cycle outcome. [2] The latter approach may be preferable in patients who present with dense pelvic adhesions and easy access only to the proximal fallopian tube.

Vitrification of mouse and human blastocysts using a novel cryoloop container-less technique.

OBJECTIVE: To vitrify mouse and human blastocysts with use of the cryoloop procedure and to assess subsequent development. DESIGN: Controlled study of vitrification of mouse and human blastocysts. SETTING: Research department of a private assisted reproductive technology unit. PATIENT(S): Blastocysts that were not suitable to be frozen were donated from patients. INTERVENTION(S): Culture of pronucleate embryos in sequential media to the blastocyst stage. MAIN OUTCOME MEASURE(S): Survival of the vitrification procedure was assessed by reexpansion, hatching, and outgrowth in culture. In addition, the viability of mouse blastocysts was assessed after transfer to pseudopregnant recipients. RESULT(S): Vitrification of mouse blastocysts did not affect the ability to reexpand, hatch, or outgrow in culture. Furthermore, implantation rates and fetal development were equivalent for nonfrozen and vitrified blastocysts. Vitrified human blastocysts were able to hatch and outgrow in culture at rates similar to nonfrozen controls. CONCLUSION(S): Cryoloop vitrification was able to cryopreserve mouse and human blastocysts without any reduction in the ability to reexpand and hatch in culture. Furthermore, viability was not reduced by the cryoloop vitrification of mouse blastocysts.

Impact of intramural leiomyomata in patients with a normal endometrial cavity on in vitro fertilization-embryo transfer cycle outcome.

OBJECTIVE: Assess the impact of intramural uterine leiomyomata and a normal endometrial cavity on IVF-ET cycle outcome. DESIGN: Retrospective case-controlled analysis. SETTING: Tertiary-care-assisted reproductive technology program. PATIENT(S): Three hundred ninety-nine consecutive fresh IVF-ET cycles were performed in patients with a normal precycle diagnostic hysteroscopy; patients were divided into four groups. Group 1: positive leiomyomata, age <40 years (n = 51 cycles); group 2: negative leiomyomata, age <40 years (n = 57 cycles); group 3: positive leiomyomata, age > or =40 years (n = 22 cycles); group 4: negative leiomyomata, age > or =40 years (n = 59 cycles). A subgroup of all group 2 patients aged 35-39 (group 2A, n = 113 cycles) was also evaluated as an additional control. INTERVENTION(S): Controlled ovarian hyperstimulation, IVF-ET. MAIN OUTCOME MEASURE(S): Implantation (IR), live birth (LBR) rates. RESULT(S): There were no significant differences in LBR among age-matched controls: group 1 (49%) versus 2 (57.5%) or 2A (57%) and group 3 (40.9%) versus 4 (32.2%). IR was significantly lower in group 1 (21.4%) versus 2 (33.3%) or 2A (33.9%) but not in group 3 (17.5%) versus 4 (11.6%). Implantation did not correlate with either mean leiomyoma diameter or volume. CONCLUSION(S): [1] LBR was not affected by the presence of intramural leiomyoma in IVF-ET patients with hysteroscopically normal endometrial cavities. [2] A significant decrease in IR was only noted in patients <40 years old. [3] Given the relatively high LBR in all groups, prophylactic surgical intervention cannot be justified, but precycle hysteroscopy evaluation is recommended.

A model for the incorporation of intracytoplasmic sperm injection into a private practice in vitro fertilization program.

OBJECTIVE: To describe a method for the training of personnel and the implementation of intracytoplasmic sperm injection (ICSI) into an IVF program. The results of the first 75 cycles are reviewed. DESIGN: Retrospective review of the first 75 consecutive ICSI procedures. SETTING: Private, community-based IVF program. MAIN OUTCOME MEASURES: The fertilization rate, damage rate, ongoing pregnancy rate (PR), and implantation rate were measured. RESULTS: Nine percent of the injected oocytes were damaged. The fertilization rate was 60%, and the cleavage rate was 98%. Fifty-nine percent of the cycles resulted in an ongoing pregnancy, and the implantation rate per embryo was 26%. CONCLUSIONS: A high initial PR can be obtained with ICSI using a systematic training regimen.

Embryo transfer: techniques and variables affecting success.

OBJECTIVE: To review the literature on the variables affecting embryo transfer success or failure and to define technical factors associated with optimal outcome. DESIGN: Literature review. RESULTS: Avoidance of blood, mucus, bacterial contamination, excessive uterine contractions, and trauma to the endometrium is associated with optimal pregnancy and implantation rates after transcervical embryo transfer. A trial transfer, ultrasonographic guidance, and use of "soft" catheters appear to facilitate successful embryo transfer. CONCLUSION: An understanding of the variables associated with embryo transfer success together with adherence to techniques shown to facilitate atraumatic embryo transfer will enhance the efficiency of IVF by maximizing embryo implantation.

Noninvasive assessment of human embryo nutrient consumption as a measure of developmental potential.

OBJECTIVE: To determine the relationship between blastocyst development and morphology and embryo metabolism. DESIGN: Noninvasive assessment of carbohydrate uptake and ammonium production by individual embryos. SETTING: Private assisted reproductive technology unit. PATIENT(S): Patients donated, with consent, cryopreserved pronucleate embryos and noncryopreserved blastocysts. INTERVENTION(S): Culture of 60 thawed pronucleate embryos in sequential media to the blastocyst stage with concomitant noninvasive analysis of embryo metabolism and analysis of 13 blastocysts from noncryopreserved embryos. MAIN OUTCOME MEASURE(S): Pyruvate and glucose consumption as well as blastocyst formation and quality. RESULT(S): Pyruvate and glucose uptakes on day 4 were significantly higher by embryos that went on to form blastocysts than by embryos that failed to develop to the blastocyst stage. Glucose uptakes were greatest in those blastocysts of highest grade, whereas pyruvate uptakes were similar irrespective of blastocyst grade, indicating that glucose is the more important nutrient for the human blastocyst. Among blastocysts of the same grade from the same patient, there was considerable spread of glucose consumption, indicating that glucose consumption may be of use in identifying blastocysts for transfer. Ammonium production by individual embryos was also measured, reflecting amino acid transamination and use by the human embryo. CONCLUSION(S): The ability to identify in culture the embryo with the highest developmental potential will facilitate the move to single-embryo transfers.

Assisted hatching in the treatment of poor prognosis in vitro fertilization candidates.

OBJECTIVE: To access the effect of augmenting IVF with assisted hatching in the treatment of poor-prognosis patients. DESIGN: Thirty-three poor-prognosis IVF patients were treated with assisted hatching and were compared with 43 control subjects without assisted hatching. SETTING: Center for Reproductive Medicine, Swedish Medical Center, Englewood, Colorado. PARTICIPANTS: Seventy-six women undergoing IVF with a poor prognosis for pregnancy. Poor prognosis was defined as Elevated day 3 FSH level; age > or = 39 years; and multiple prior IVF failures. MAIN OUTCOME MEASURES: Pregnancy and implantation rates per embryo. RESULTS: The incidence of ongoing pregnancy in the assisted hatching group was 64% compared with 19% in the control group. Implantation rate per embryo transferred was 33% in the assisted hatching group versus 6.5% in the control group. CONCLUSIONS: These results demonstrate that assisted hatching, when applied to poor-prognosis patients, improves embryonic implantation and pregnancy rates.