Letrozole versus clomiphene for infertility in the polycystic ovary syndrome.

BACKGROUND: Clomiphene is the current first-line infertility treatment in women with the polycystic ovary syndrome, but aromatase inhibitors, including letrozole, might result in better pregnancy outcomes. METHODS: In this double-blind, multicenter trial, we randomly assigned 750 women, in a 1:1 ratio, to receive letrozole or clomiphene for up to five treatment cycles, with visits to determine ovulation and pregnancy, followed by tracking of pregnancies. The polycystic ovary syndrome was defined according to modified Rotterdam criteria (anovulation with either hyperandrogenism or polycystic ovaries). Participants were 18 to 40 years of age, had at least one patent fallopian tube and a normal uterine cavity, and had a male partner with a sperm concentration of at least 14 million per milliliter; the women and their partners agreed to have regular intercourse with the intent of conception during the study. The primary outcome was live birth during the treatment period. RESULTS: Women who received letrozole had more cumulative live births than those who received clomiphene (103 of 374 [27.5%] vs. 72 of 376 [19.1%], P=0.007; rate ratio for live birth, 1.44; 95% confidence interval, 1.10 to 1.87) without significant differences in overall congenital anomalies, though there were four major congenital anomalies in the letrozole group versus one in the clomiphene group (P=0.65). The cumulative ovulation rate was higher with letrozole than with clomiphene (834 of 1352 treatment cycles [61.7%] vs. 688 of 1425 treatment cycles [48.3%], P<0.001). There were no significant between-group differences in pregnancy loss (49 of 154 pregnancies in the letrozole group [31.8%] and 30 of 103 pregnancies in the clomiphene group [29.1%]) or twin pregnancy (3.4% and 7.4%, respectively). Clomiphene was associated with a higher incidence of hot flushes, and letrozole was associated with higher incidences of fatigue and dizziness. Rates of other adverse events were similar in the two treatment groups. CONCLUSIONS: As compared with clomiphene, letrozole was associated with higher live-birth and ovulation rates among infertile women with the polycystic ovary syndrome. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others; ClinicalTrials.gov number, NCT00719186.).

Meta-analysis of loci associated with age at natural menopause in African-American women.

Age at menopause marks the end of a woman's reproductive life and its timing associates with risks for cancer, cardiovascular and bone disorders. GWAS and candidate gene studies conducted in women of European ancestry have identified 27 loci associated with age at menopause. The relevance of these loci to women of African ancestry has not been previously studied. We therefore sought to uncover additional menopause loci and investigate the relevance of European menopause loci by performing a GWAS meta-analysis in 6510 women with African ancestry derived from 11 studies across the USA. We did not identify any additional loci significantly associated with age at menopause in African Americans. We replicated the associations between six loci and age at menopause (P-value < 0.05): AMHR2, RHBLD2, PRIM1, HK3/UMC1, BRSK1/TMEM150B and MCM8. In addition, associations of 14 loci are directionally consistent with previous reports. We provide evidence that genetic variants influencing reproductive traits identified in European populations are also important in women of African ancestry residing in USA.

The Pregnancy in Polycystic Ovary Syndrome II study: baseline characteristics and effects of obesity from a multicenter randomized clinical trial.

OBJECTIVE: To summarize baseline characteristics from a large multicenter infertility clinical trial. DESIGN: Cross-sectional baseline data from a double-blind randomized trial of two treatment regimens (letrozole vs. clomiphene). SETTING: Academic Health Centers throughout the United States. PATIENT(S): Seven hundred fifty women with polycystic ovary syndrome (PCOS) and their male partners took part in the study. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Historic, biometric, biochemical, and questionnaire parameters. RESULT(S): Females averaged 30 years and were obese (body mass index [BMI] 35) with ∼20% from a racial/ethnic minority. Most (87%) were hirsute and nulligravid (63%). Most of the women had an elevated antral follicle count and enlarged ovarian volume on ultrasound. Women had elevated mean circulating androgens, LH-to-FSH ratio (∼2), and antimüllerian hormone levels (8.0 ng/mL). In addition, women had evidence for metabolic dysfunction with elevated mean fasting insulin and dyslipidemia. Increasing obesity was associated with decreased LH-to-FSH levels, antimüllerian hormone levels, and antral follicle counts but increasing cardiovascular risk factors, including prevalence of the metabolic syndrome. Men were obese (BMI 30) and had normal mean semen parameters. CONCLUSION(S): The treatment groups were well matched at baseline. Obesity exacerbates select female reproductive and most metabolic parameters. We have also established a database and sample repository that will eventually be accessible to investigators. CLINICAL TRIAL REGISTRATION NUMBER: NCT00719186.

Effects of a dietary intervention and weight change on vasomotor symptoms in the Women's Health Initiative.

OBJECTIVE: The aim of this study was to determine whether a dietary intervention designed to reduce fat intake and increase intake of fruit, vegetables, and whole grains, and weight loss, reduces vasomotor symptoms (VMS; ie, hot flashes or night sweats) in postmenopausal women. METHODS: We included 17,473 postmenopausal US women, ages 50 to 79 years, at baseline who participated in the Women's Health Initiative Dietary Modification trial and were not taking menopausal hormone therapy. Logistic regression was used to evaluate associations. RESULTS: In multivariate-adjusted analyses, with simultaneous adjustment for the intervention and weight change, assignment to the dietary intervention versus the control arm was significantly (odds ratio [OR], 1.14; 95% CI, 1.01-1.28) related to a higher likelihood of symptom elimination among women with VMS at baseline. In addition, women with symptoms at baseline who lost 10 lb or more (OR, 1.23; 95% CI, 1.05-1.46) or lost 10% or more of their baseline body weight (OR, 1.56; 95% CI, 1.21-2.02) between baseline and year 1 were significantly more likely to eliminate VMS compared with those who maintained weight. Upon examining the joint effect of the dietary modification and weight loss, compared with women in the control arm who maintained weight, women who lost substantial weight (≥ 10%) as a part of the intervention (OR, 1.89; 95% CI, 1.39-2.57) but not as part of the control arm (OR, 1.40; 95% CI, 0.92-2.13) were significantly more likely to end VMS, although these two groups did not differ significantly from each other. Large weight loss (>22 lb), but not dietary changes, was related to the elimination of moderate/severe VMS. CONCLUSIONS: Weight loss as part of a healthy dietary modification may help eliminate VMS among postmenopausal women.

Endometrial shedding effect on conception and live birth in women with polycystic ovary syndrome.

OBJECTIVE: To estimate whether progestin-induced endometrial shedding, before ovulation induction with clomiphene citrate, metformin, or a combination of both, affects ovulation, conception, and live birth rates in women with polycystic ovary syndrome (PCOS). METHODS: A secondary analysis of the data from 626 women with PCOS from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Cooperative Reproductive Medicine Network trial was performed. Women had been randomized to up to six cycles of clomiphene citrate alone, metformin alone, or clomiphene citrate plus metformin. Women were assessed for occurrence of ovulation, conception, and live birth in relation to prior bleeding episodes (after either ovulation or exogenous progestin-induced withdrawal bleed). RESULTS: Although ovulation rates were higher in cycles preceded by spontaneous endometrial shedding than after anovulatory cycles (with or without prior progestin withdrawal), both conception and live birth rates were significantly higher after anovulatory cycles without progestin-induced withdrawal bleeding (live births per cycle: spontaneous menses 2.2%; anovulatory with progestin withdrawal 1.6%; anovulatory without progestin withdrawal 5.3%; P<.001). The difference was more marked when rate was calculated per ovulation (live births per ovulation: spontaneous menses 3.0%; anovulatory with progestin withdrawal 5.4%; anovulatory without progestin withdrawal 19.7%; P<.001). CONCLUSION: Conception and live birth rates are lower in women with PCOS after a spontaneous menses or progestin-induced withdrawal bleeding as compared with anovulatory cycles without progestin withdrawal. The common clinical practice of inducing endometrial shedding with progestin before ovarian stimulation may have an adverse effect on rates of conception and live birth in anovulatory women with PCOS. LEVEL OF EVIDENCE: II.

NOX5 in human spermatozoa: expression, function, and regulation.

Physiological and pathological processes in spermatozoa involve the production of reactive oxygen species (ROS), but the identity of the ROS-producing enzyme system(s) remains a matter of speculation. We provide the first evidence that NOX5 NADPH oxidase is expressed and functions in human spermatozoa. Immunofluorescence microscopy detected NOX5 protein in both the flagella/neck region and the acrosome. Functionally, spermatozoa exposed to calcium ionophore, phorbol ester, or H(2)O(2) exhibited superoxide anion production, which was blocked by addition of superoxide dismutase, a Ca(2+) chelator, or inhibitors of either flavoprotein oxidases (diphenylene iododonium) or NOX enzymes (GKT136901). Consistent with our previous overexpression studies, we found that H(2)O(2)-induced superoxide production by primary sperm cells was mediated by the non-receptor tyrosine kinase c-Abl. Moreover, the H(V)1 proton channel, which was recently implicated in spermatozoa motility, was required for optimal superoxide production by spermatozoa. Immunoprecipitation experiments suggested an interaction among NOX5, c-Abl, and H(V)1. H(2)O(2) treatment increased the proportion of motile sperm in a NOX5-dependent manner. Statistical analyses showed a pH-dependent correlation between superoxide production and enhanced sperm motility. Collectively, our findings show that NOX5 is a major source of ROS in human spermatozoa and indicate a role for NOX5-dependent ROS generation in human spermatozoa motility.

The Pregnancy in Polycystic Ovary Syndrome II (PPCOS II) trial: rationale and design of a double-blind randomized trial of clomiphene citrate and letrozole for the treatment of infertility in women with polycystic ovary syndrome.

Polycystic Ovary Syndrome (PCOS) is a common cause of female infertility and first line treatment is currently oral clomiphene citrate, a selective estrogen receptor modulator, which results in both a high nonresponse rate and multiple pregnancy rate. Aromatase inhibitors such as letrozole may have more favorable ovarian and endometrial effects. The goal of the Pregnancy in Polycystic Ovary Syndrome II (PPCOSII) study is to determine the safety and efficacy of clomiphene citrate (CC) compared to letrozole, in achieving live birth in infertile women with PCOS. The population will consist of 750 infertile women with PCOS. Additionally, the couple will have no other major infertility factor. This will be a multi-center, prospective, double-blind clinical trial of CC vs. letrozole for 5 treatment cycles (or approximately up to 25 weeks). The randomization scheme will be coordinated through the central data coordinating center (DCC) and the randomization is stratified by each participating site. After progestin withdrawal as needed, 750 women will be equally randomized to two different treatment arms: A) CC 50mg every day for 5 days (days 3-7 of cycle), or B) letrozole 2.5mg every day for 5 days (days 3-7 of cycle), for a total of 5 cycles or 25 weeks. The dose will be increased in subsequent cycles in both treatment groups for non-response or poor ovulatory response up to a maximum of 150 mg of CC a day (×5 days) or 7.5mg of letrozole a day (×5 days). The primary analysis will use an intent-to-treat approach to examine differences in the live birth rate in the two treatment arms.

Replication of loci influencing ages at menarche and menopause in Hispanic women: the Women's Health Initiative SHARe Study.

Several genome-wide studies have identified loci associated with reproductive traits, such as ages of menarche and menopause, in women of European ancestry. In this study, we investigated the relevance of these loci in minority US Hispanic women. We utilized data from 3468 women who were genotyped as a part of the Women's Health Initiative SNP Health Association Resource. We replicated associations of eight loci (LRP18, LIN28B, CENPW, INHBA, TMEM38B, ZNF483, NFAT5 and OLFM2) with age at menarche, and of two loci (MCM8 and BRSK1/TMEM150B) with age at menopause. The MCM8 locus was also associated with early menopause risk. Three loci (CENPW, MCM8 and BRSK1/TMEM150B) were associated with the length of reproductive lifespan. We provide evidence that genetic variants influencing reproductive traits identified in European populations are also important in minority US Hispanic women.

Recruitment challenges of a multicenter randomized controlled varicocelectomy trial.

OBJECTIVE: To review reasons for suboptimal recruitment for a randomized controlled trial (RCT) of varicocelectomy versus intrauterine insemination (IUI) for treatment of male infertility and to suggest means for improving future study recruitment. DESIGN: Survey of Reproductive Medicine Network (RMN) participating sites. SETTING: Reproductive Medicine Network. PATIENT(S): None. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Ascertain reasons for inadequate recruitment and suggest improvements for future varicocelectomy trails. RESULT(S): This study screened seven and enrolled three couples, with the first couple randomized on June 30, 2010. The study was subsequently stopped on March 30, 2011. The following themes were cited most frequently by sites and therefore determined to be most likely to have played a role in suboptimal recruitment: [1] men must be screened at the beginning of a couple's infertility evaluation, [2] inclusion of infertile women who had failed previous fertility interventions appeared to be associated with the couple's intolerance of a placebo arm, and [3] an apparent bias against the use of unstimulated IUI cycles indicated a prejudicial preference for surgical intervention in the male partner. CONCLUSION(S): Improved recruitment may be realized through screening infertile men as early as possible while minimizing study-related time commitments. Focused patient education may promote improved equipoise and acceptance of a placebo arm in male infertility studies. Creative approaches to implementing varicocelectomy trials must be considered in addition to having a network of motivated researchers who carry a high volume of possible study participants because very large numbers may need to be screened to complete the clinical trial enrollment.

Patterns and predictors of sexual activity among women in the Hormone Therapy trials of the Women's Health Initiative.

OBJECTIVE: The aim of this study was to determine the patterns and predictors of sexual activity in the Hormone Therapy (HT) Trials of the Women's Health Initiative (WHI). METHODS: Sexual activity questions were administered to 27,347 women ages 50 to 79 years at baseline and at year 1 and to a random 8.6% subsample at years 3 and 6. The associations with demographic and health characteristics were determined. RESULTS: Sexual activity at baseline was 60.7%, 44.9%, and 28.2% in the 50- to 59-, 60- to 69-, and 70- to 79-year-old age groups, respectively. Most of the participants were satisfied with their current sexual activity (63.2%). Of those dissatisfied, 57% preferred more sexual activity. Vaginal atrophy correlated with sexual inactivity at baseline (P < 0.001). The correlates associated with stopping sexual activity at year 1 included poor/fair self-rated health, lack of satisfaction with quality of life, depression, and loss of partner (P < 0.001). The strongest predictor of sexual activity at year 1 was sexual activity at baseline (odds ratio, 96.71; 95% CI, 81.90-114.20). A subset analysis of women adherent with HT or placebo at years 3 and 6 suggested that HT was associated with a higher percentage of participants reporting sexual activity (P = 0.01). CONCLUSIONS: Most women in the WHI HT Trials were satisfied with their sexual activity. Of those who were dissatisfied, the majority preferred more, rather than less, sexual activity. Vaginal atrophy at baseline correlated with sexual inactivity, and sexual activity at baseline was the strongest identified predictor of sexual activity at year 1. HT use was not predictive of ongoing sexual activity in the intent-to-treat analysis. This report further characterizes the participants in the WHI HT trials and reveals the complexity of factors related to the prevalence of sexual activity and satisfaction.

Establishing a biologic specimens repository for reproductive clinical trials: technical aspects.

The individual research group or independent investigator often requires access to samples from a unique well characterized subject population. Cohorts of such samples from a well-defined comparative population are rare and limited access can impede progress. This bottleneck can be removed by accessing the samples provided by biorepositories such as the NIH/NICHD Cooperative Reproductive Medicine Network (RMN) Biorepository (detailed in the preceeding manuscript in this issue. In those cases where the individual research group or independent investigator already has access to a unique population, comparisons between well-defined groups are often sought to contextualize the data. In both cases seamless integration of data resources associated with the samples is required to ensure optimal comparisons. At the most basic level this requires standardization of sample collection and storage, as well as a de-identified data base containing demographic, clinical, and laboratory values. To facilitate such interoperability, the reagents and protocols that have been adopted by the RMN Biorepository for the collection and storage of serum, blood, saliva and sperm are described.

Proactively establishing a biologic specimens repository for large clinical trials: an idea whose time has come.

Large randomized clinical trials are becoming more costly, and resources to support them increasingly scarce. Biologic materials, such as blood, DNA, body fluids, or tissue samples collected and stored as a component of these studies represent an invaluable resource, to answer immediate secondary hypotheses, but also as archived material, linked to the study data, for the use of investigators long into the future. The regulatory climate surrounding the storage and future unconstrained utilization of biologic materials is evolving quickly. It is no longer acceptable simply to store samples and use them in an unbridled and unregulated fashion. Thus, to fully utilize the tremendous potential of biologic samples generated from large clinical trials and their related databases, investigators should consider proactively creating a biologic specimen repository, or biorepository. A repository likely assures appropriate subject consent, sample provenance, secure storage, and codified procedures for sample and data retrieval and sharing that protect the subject's confidentiality, the investigator's need for accurate data, and the limited resource. Importantly, the biorepository specimens/samples are typically collected in addition to local and core specimens obtained for the parent study that provide baseline assessments for safety and efficacy outcomes.

Serum beta human chorionic gonadotropin levels can inform outcome counseling after in vitro fertilization.

The predictive value of serum beta hCG level for fetal cardiac motion and pregnancy outcome after IVF was evaluated. The serum hCG level 12 days after ET is a useful predictor of subsequent presence of fetal cardiac activity and live birth and may assist clinicians in counseling patients regarding their IVF outcome.

Estimating rates of multiple gestation pregnancies: sample size calculation from the assessment of multiple intrauterine gestations from ovarian stimulation (AMIGOS) trial.

Infertility afflicts 15% of couples who wish to conceive. Despite intensive evaluation of both male and female partners, the etiology may remain unknown leading to a diagnosis of unexplained infertility. For such couples, treatment often entails ovulation induction (OI) with fertility medications coupled with intrauterine insemination. Complications of this therapy include ovarian hyperstimulation syndrome and creation of multiple gestation pregnancies, which can be complicated by preterm labor and delivery, and the associated neonatal morbidity and expense of care for preterm infants. The Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS) study is designed to assess whether OI in couples with unexplained infertility with an aromatase inhibitor produces mono-follicular development in most cycles, thereby reducing multiple gestations while maintaining a comparable pregnancy success rate to that achieved by OI with either gonadotropins or clomiphene citrate. These results will provide future guidance of therapy for couples with unexplained infertility, and if comparable pregnancy rates are achieved with a substantial reduction in multiple gestations, the public health benefit will be considerable.

Increasing burden of institutional review in multicenter clinical trials of infertility: the Reproductive Medicine Network experience with the Pregnancy in Polycystic Ovary Syndrome (PPCOS) I and II studies.

UNLABELLED: Many clinical investigators think that the burden of Institutional Review Board (IRB) requirements has been consistently increasing over recent years, although there are few objective data describing these trends. Over a period of 7 years, the Reproductive Medicine Network observed a significant increase in the size and requirements of IRB submissions and significant variability of IRB performance in reviewing multicenter trials. These additional regulatory and administrative demands represent substantial burdens to researchers and to the IRBs themselves. It is timely to consider whether these changes better protect the interests and safety of human research participants. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT00068861 and NCT00719186.

In vitro fertilization outcomes in Hispanics versus non-Hispanic whites.

The in vitro fertilization (IVF) outcomes, including clinical intrauterine gestation rate and live birth rate, between Hispanic and non-Hispanic white women were compared, and there were no differences. Hispanics were more likely to have a diagnosis of tubal factor infertility, whereas non-Hispanic white women were more likely to have endometriosis as their infertility diagnosis.

Health outcomes after stopping conjugated equine estrogens among postmenopausal women with prior hysterectomy: a randomized controlled trial.

CONTEXT: The Women's Health Initiative Estrogen-Alone Trial was stopped early after a mean of 7.1 years of follow-up because of an increased risk of stroke and little likelihood of altering the balance of risk to benefit by the planned trial termination date. Postintervention health outcomes have not been reported. OBJECTIVE: To examine health outcomes associated with randomization to treatment with conjugated equine estrogens (CEE) among women with prior hysterectomy after a mean of 10.7 years of follow-up through August 2009. DESIGN, SETTING, AND PARTICIPANTS: The intervention phase was a double-blind, placebo-controlled, randomized clinical trial of 0.625 mg/d of CEE compared with placebo in 10,739 US postmenopausal women aged 50 to 79 years with prior hysterectomy. Follow-up continued after the planned trial completion date among 7645 surviving participants (78%) who provided written consent. MAIN OUTCOME MEASURES: The primary outcomes were coronary heart disease (CHD) and invasive breast cancer. A global index of risks and benefits included these primary outcomes plus stroke, pulmonary embolism, colorectal cancer, hip fracture, and death. RESULTS: The postintervention risk (annualized rate) for CHD among women assigned to CEE was 0.64% compared with 0.67% in the placebo group (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.75-1.25), 0.26% vs 0.34%, respectively, for breast cancer (HR, 0.75; 95% CI, 0.51-1.09), and 1.47% vs 1.48%, respectively, for total mortality (HR, 1.00; 95% CI, 0.84-1.18). The risk of stroke was no longer elevated during the postintervention follow-up period and was 0.36% among women receiving CEE compared with 0.41% in the placebo group (HR, 0.89; 95% CI, 0.64-1.24), the risk of deep vein thrombosis was lower at 0.17% vs 0.27%, respectively (HR, 0.63; 95% CI, 0.41-0.98), and the risk of hip fracture did not differ significantly and was 0.36% vs 0.28%, respectively (HR, 1.27; 95% CI, 0.88-1.82). Over the entire follow-up, lower breast cancer incidence in the CEE group persisted and was 0.27% compared with 0.35% in the placebo group (HR, 0.77; 95% CI, 0.62-0.95). Health outcomes were more favorable for younger compared with older women for CHD (P = .05 for interaction), total myocardial infarction (P = .007 for interaction), colorectal cancer (P = .04 for interaction), total mortality (P = .04 for interaction), and global index of chronic diseases (P = .009 for interaction). CONCLUSIONS: Among postmenopausal women with prior hysterectomy followed up for 10.7 years, CEE use for a median of 5.9 years was not associated with an increased or decreased risk of CHD, deep vein thrombosis, stroke, hip fracture, colorectal cancer, or total mortality. A decreased risk of breast cancer persisted. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00000611.

Vasomotor symptoms and cardiovascular events in postmenopausal women.

OBJECTIVE: Emerging evidence suggests that women with menopausal vasomotor symptoms (VMS) have increased cardiovascular disease (CVD) risk as measured by surrogate markers. We investigated the relationships between VMS and clinical CVD events and all-cause mortality in the Women's Health Initiative Observational Study (WHI-OS). METHODS: We compared the risk of incident CVD events and all-cause mortality between four groups of women (total N = 60,027): (1) no VMS at menopause onset and no VMS at WHI-OS enrollment (no VMS [referent group]), (2) VMS at menopause onset but not at WHI-OS enrollment (early VMS), (3) VMS at both menopause onset and WHI-OS enrollment (persistent VMS [early and late]), and (4) VMS at WHI-OS enrollment but not at menopause onset (late VMS). RESULTS: For women with early VMS (n = 24,753), compared with no VMS (n = 18,799), hazard ratios (95% CIs) in fully adjusted models were as follows: major coronary heart disease (CHD), 0.94 (0.84-1.06); stroke, 0.83 (0.72-0.96); total CVD, 0.89 (0.81-0.97); and all-cause mortality, 0.92 (0.85-0.99). For women with persistent VMS (n = 15,084), there was no significant association with clinical events. For women with late VMS (n = 1,391), compared with no VMS, hazard ratios (95% CIs) were as follows: major CHD, 1.32 (1.01-1.71); stroke, 1.14 (0.82-1.59); total CVD, 1.23 (1.00-1.52); and all-cause mortality, 1.29 (1.08-1.54). CONCLUSIONS: Early VMS were not associated with increased CVD risk. Rather, early VMS were associated with decreased risk of stroke, total CVD events, and all-cause mortality. Late VMS were associated with increased CHD risk and all-cause mortality. The predictive value of VMS for clinical CVD events may vary with the onset of VMS at different stages of menopause. Further research examining the mechanisms underlying these associations is needed. Future studies will also be necessary to investigate whether VMS that develop for the first time in the later postmenopausal years represent a pathophysiologic process distinct from the classic perimenopausal VMS.

Derivation and characterization of novel nonhuman primate embryonic stem cell lines from in vitro-fertilized baboon preimplantation embryos.

The development of nonhuman primate (NHP) embryonic stem cell (ESC) models holds great promise for cell-mediated treatment of debilitating diseases and to address numerous unanswered questions regarding the therapeutic efficacy of ESCs while supplanting ethical considerations involved with human studies. Here we report successful establishment and characterization of 3 novel baboon (Papio cynocephalus) ESC lines from the inner cell mass of intracytoplasmic sperm injection-derived blastocysts. Embryos were cultured in an improved baboon embryo in vitro culture protocol. The inner cell mass of blastocyst was laser-dissected and plated on mouse embryonic fibroblast feeder cell monolayer in the NHP ESC culture medium. Three cell lines with characteristic ESC morphology have been cultured through an extended period (>14 months), with 2 male cell lines (UT-1 and -2) and 1 female cell line (UT-3) displaying normal baboon karyotypes. Reverse transcription-polymerase chain reaction analysis confirmed that all 3 lines express primate ESC pluripotency markers, including OCT-4, NANOG, SOX-2, TERT, TDGF, LEFTYA, and REX-1. All 3 lines demonstrated positive immunocytochemical staining for OCT-4, stage-specific embryonic antigen-3, stage-specific embryonic antigen-4, TRA-1-60, and TRA-1-81. Baboon ESCs injected into NOD/SCID mice formed teratomas with all 3 germ layers. In addition, embryoid body-like spherical structures were derived and initial outgrowth was observed when embedded into extracellular matrix Matrigel. The ESC lines established in this NHP model have the potential to extend our knowledge in the fields of developmental biology, regenerative medicine, and future applications, including preclinical safety assessment of in vivo stem cell therapy.

Ovarian stimulation, in vitro fertilization, and effects of culture conditions on baboon preimplantation embryo development.

OBJECTIVE: To evaluate the effects of ovarian stimulation and intracytoplasmic sperm injection (ICSI)-induced fertilization and efficacy of various culture systems on in vitro development of baboon embryos. DESIGN: In vitro study, animal model. SETTING: Research laboratory. ANIMAL(S): Baboons in laboratory animal research facility. INTERVENTION(S): Baboons received FSH (75 IU daily) for 7 to 8 days and FSH/LH (75/75 IU daily) for 3 days, followed by hCG (2,000 IU). Oocytes were retrieved laparoscopically 36 hours after hCG. Intracytoplasmic sperm injection was performed on metaphase II (MII) oocytes. Fertilized embryos were placed into different culture conditions and feeder cell coculture. Embryo development was observed through the most advanced stages, including blastocyst formation. MAIN OUTCOME MEASURE(S): Oocytes retrieved, fertilization rates, multicell embryo rates, and blastocyst rates. RESULT(S): Baboon oocytes (n = 1,924, from 49 cycles) were retrieved. Significant heterogeneity was seen in ovarian response to exogenous gonadotropins and subsequent oocyte maturation. The percentage of MII oocytes showed no significant difference among individual female baboons and stimulation cycles. Nearly two thirds of MII oocytes were successfully fertilized with ICSI. Blastocyst rates varied significantly among embryos in different treatments. Coculture with feeder cells in P1/Blast, Quinn's Advantage, and Sydney IVF media generated better blastocyst rates. CONCLUSION(S): We tested multiple media and feeder cell combinations to optimize culture conditions in baboon embryo culture and obtained a high blastocyst rate similar to those reported for rhesus monkey embryos cultured in vitro, but still lower than with assisted reproductive technologies in women.