Erratum: Pluripotent state transitions coordinate morphogenesis in mouse and human embryos.

This corrects the article DOI: 10.1038/nature24675.

Pluripotent state transitions coordinate morphogenesis in mouse and human embryos.

The foundations of mammalian development lie in a cluster of embryonic epiblast stem cells. In response to extracellular matrix signalling, these cells undergo epithelialization and create an apical surface in contact with a cavity, a fundamental event for all subsequent development. Concomitantly, epiblast cells transit through distinct pluripotent states, before lineage commitment at gastrulation. These pluripotent states have been characterized at the molecular level, but their biological importance remains unclear. Here we show that exit from an unrestricted naive pluripotent state is required for epiblast epithelialization and generation of the pro-amniotic cavity in mouse embryos. Embryonic stem cells locked in the naive state are able to initiate polarization but fail to undergo lumenogenesis. Mechanistically, exit from naive pluripotency activates an Oct4-governed transcriptional program that results in expression of glycosylated sialomucin proteins and the vesicle tethering and fusion events of lumenogenesis. Similarly, exit of epiblasts from naive pluripotency in cultured human post-implantation embryos triggers amniotic cavity formation and developmental progression. Our results add tissue-level architecture as a new criterion for the characterization of different pluripotent states, and show the relevance of transitions between these states during development of the mammalian embryo.

Physiological, hyaluronan-selected intracytoplasmic sperm injection for infertility treatment (HABSelect): a parallel, two-group, randomised trial.

BACKGROUND: Sperm selection strategies aimed at improving success rates of intracytoplasmic sperm injection (ICSI) include binding to hyaluronic acid (herein termed hyaluronan). Hyaluronan-selected sperm have reduced levels of DNA damage and aneuploidy. Use of hyaluronan-based sperm selection for ICSI (so-called physiological ICSI [PICSI]) is reported to reduce the proportion of pregnancies that end in miscarriage. However, the effect of PICSI on livebirth rates is uncertain. We aimed to investigate the efficacy of PICSI versus standard ICSI for improving livebirth rates among couples undergoing fertility treatment. METHODS: This parallel, two-group, randomised trial included couples undergoing an ICSI procedure with fresh embryo transfer at 16 assisted conception units in the UK. Eligible women (aged 18-43 years) had a body-mass index of 19-35 kg/m2 and a follicle-stimulating hormone (FSH) concentration of 3·0-20·0 mIU/mL or, if no FSH measurement was available, an anti-müllerian hormone concentration of at least 1·5 pmol/L. Eligible men (aged 18-55 years) had not had a vasovasostomy or been treated for cancer in the 24 months before recruitment and were able, after at least 3 days of sexual abstinence, to produce freshly ejaculated sperm for the treatment cycle. Couples were randomly assigned (1:1) with an online system to receive either PICSI or a standard ICSI procedure. The primary outcome was full-term (≥37 weeks' gestational age) livebirth, which was assessed in all eligible couples who completed follow-up. This trial is registered, number ISRCTN99214271. FINDINGS: Between Feb 1, 2014, and Aug 31, 2016, 2772 couples were randomly assigned to receive PICSI (n=1387) or ICSI (n=1385), of whom 2752 (1381 in the PICSI group and 1371 in the ICSI group) were included in the primary analysis. The term livebirth rate did not differ significantly between PICSI (27·4% [379/1381]) and ICSI (25·2% [346/1371]) groups (odds ratio 1·12, 95% CI 0·95-1·34; p=0·18). There were 56 serious adverse events in total, including 31 in the PICSI group and 25 in the ICSI group; most were congenital abnormalities and none were attributed to treatment. INTERPRETATION: Compared with ICSI, PICSI does not significantly improve term livebirth rates. The wider use of PICSI, therefore, is not recommended at present. FUNDING: National Institute for Health Research Efficacy and Mechanism Evaluation Programme.

The impact of adenomyosis on the outcome of IVF-embryo transfer.

Our study examined the impact of adenomyosis on the chance of clinical pregnancy after IVF and embryo transfer (IVF-ET). This was a prospective multicentre study from April 2013 to October 2015. We included 375 women with history of infertility who attended for a 3D scan prior to IVF-ET. A total of 150/375 (40.0%, 95% confidence interval [CI] 35.2-45.0) women had clinical pregnancy. Women with any feature of adenomyosis had a lower clinical pregnancy rate (21/72 [29.2%, 95% CI 18.6-39.6] versus 129/303 [42.6%, 95% CI 37.1-48.2], P = 0.044, relative risk (RR) 0.68 [95% CI 0.47-1.00]). Logistic regression selected an adenomyosis score of 4 or higher as an independent predictor of clinical pregnancy (odds ratio [OR] 0.35 [95% CI 0.15-0.82]). Estimated probability of clinical pregnancy decreased from 42.7% (95% CI 37.1-48.3) for women with no adenomyosis features to 22.9% (95% CI 13.4-32.6) for those with four and 13.0% (95% CI 2.2-23.9) for those with all seven. Women with adenomyosis have lower clinical pregnancy rate after IVF-ET. Condition severity expressed as a number of morphological features on ultrasound scan increases the magnitude of the effect.

Live birth and perinatal outcomes following stimulated and unstimulated IVF: analysis of over two decades of a nationwide data.

STUDY QUESTION: Does ovarian stimulation affect perinatal outcomes of preterm birth (PTB) and low birth weight (LBW) following IVF treatment. SUMMARY ANSWER: Despite no significant differences in the risks of PTB and LBW between stimulated and unstimulated IVF in the present study, the study cannot exclude the effect of ovarian stimulation on the perinatal outcomes following IVF. WHAT IS ALREADY KNOWN: Pregnancies resulting from assisted reproductive treatments (ART) are associated with a higher risk of pregnancy complications compared to spontaneously conceived pregnancies attributed to the underlying infertility and the in vitro fertilization techniques. It is of interest to determine the effect size of ovarian stimulation use in achieving a live birth and whether ovarian stimulation that is routinely used in IVF, affects perinatal outcomes of birth weight and gestational age at delivery compared to unstimulated IVF. STUDY DESIGN, SIZE, DURATION: Anonymous data were obtained from the Human Fertilisation and Embryology Authority (HFEA), the statutory regulator of ART in the UK. The HFEA has collected data prospectively on all ART performed in the UK since 1991. Data from 1991 to 2011 comprising a total of 591 003 fresh IVF ± ICSI cycles involving 584 835 stimulated IVF cycles and 6168 unstimulated IVF cycles were analyzed. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data on all women undergoing either stimulated or unstimulated fresh IVF ± ICSI cycles during the period from 1991 to 2011 were analyzed to compare live birth rates, singleton live birth rates, perinatal outcomes of PTB, early PTB (<32 weeks), LBW and very LBW (<1500 grams) among singleton live births. Adjusted logistic regression was performed for each perinatal outcome for confounding factors: female age, period of treatment, cause of infertility, number of previous IVF cycles and previous live birth. MAIN RESULTS AND THE ROLE OF CHANCE: Analysis of the large nationwide data demonstrated 3.5 times (95% confidence interval (CI): 3.1-3.9) as many unstimulated IVF cycles being required to achieve one live birth compared to stimulated IVF and 2.9 times (95% CI: 2.6-3.2) as many unstimulated IVF cycles being required to achieve one singleton live birth compared to stimulated IVF. There was no significant difference in the unadjusted odds for PTB (odds ratio (OR) 1.27, 95% CI: 0.80-2.00) and LBW (OR 1.48, 95% CI: 0.90-2.42) between stimulated and unstimulated IVF cycles. There was no significant difference in the risk of the adverse perinatal outcomes after adjusting for potential confounders; PTB (adjusted odds ratio (aOR) 1.43, 95% CI: 0.91-2.26) and LBW (aOR 1.58, 95% CI: 0.96-2.58). LIMITATIONS, REASONS FOR CAUTION: Although the analysis was adjusted for a number of important confounders, the dataset had no information on smoking, body mass index (BMI) and the medical history of women during pregnancy to allow adjustment. Anonymized nature of the dataset did not make it permissible to analyse one cycle per woman. Given the smaller number of perinatal events with unstimulated IVF, a larger study is needed to investigate further. WIDER IMPLICATIONS OF THE FINDINGS: Analysis of this large dataset demonstrates that ovarian stimulation has a vital role in maximizing efficacy of IVF. Although there were no significant differences for PTB and LBW following stimulated compared to unstimulated IVF, the CIs were wide enough to include possible clinically important effects. STUDY FUNDING/COMPETING INTERESTS: No funding was obtained. There are no competing interests to declare.

Cassandra's prophecy and the trend of delaying childbearing: is there a simple answer to this complex problem?

There is a trend to later childbearing, but is the solution offered by Jane Everywoman appropriate or proportionate? Her case is, as she says herself, not necessarily representative and in describing it in such painful detail, might she alarm many women unnecessarily?

Treatment algorithms for high responders: What we can learn from randomized controlled trials, real-world data and models.

A high ovarian response to conventional ovarian stimulation (OS) is characterized by an increased number of follicles and/or oocytes compared with a normal response (10-15 oocytes retrieved). According to current definitions, a high response can be diagnosed before oocyte pick-up when >18-20 follicles ≥11-12 mm are observed on the day of ovulation triggering; high response can be diagnosed after oocyte pick-up when >18-20 oocytes have been retrieved. Women with a high response are also at high risk of early ovarian hyper-stimulation syndrome (OHSS)/or late OHSS after fresh embryo transfers. Women at risk of high response can be diagnosed before stimulation based on several indices, including ovarian reserve markers (anti-Müllerian hormone [AMH] and antral follicle count [AFC], with cutoff values indicative of a high response in patients with PCOS of >3.4 ng/mL for AMH and >24 for AFC). Owing to the high proportion of high responders who are at the risk of developing OHSS (up to 30%), this educational article provides a framework for the identification and management of patients who fall into this category. The risk of high response can be greatly reduced through appropriate management, such as individualized choice of the gonadotropin starting dose, dose adjustment based on hormonal and ultrasound monitoring during OS, the choice of down-regulation protocol and ovulation trigger, and the choice between fresh or elective frozen embryo transfer. Appropriate management strategies still need to be defined for women who are predicted to have a high response and those who have an unexpected high response after starting treatment.

Local endometrial injury and IVF outcome: a systematic review and meta-analysis.

A systematic review was conducted of the influence of local endometrial injury (LEI) on the outcome of the subsequent IVF cycle. MEDLINE, EMBASE, the Cochrane Library, National Research Register, ISI Conference Proceedings, ISRCTN Register and Meta-register were searched for randomized controlled trials to October 2011. The review included all trials comparing the outcome of IVF treatment in patients who had LEI in the cycle preceding their IVF treatment with controls in which endometrial injury was not performed. The main outcome measures were clinical pregnancy and live birth rates. In total, 901 participants were included in two randomized (n=193) and six non-randomized controlled studies (n=708). The quality of the studies was variable. Meta-analysis showed that clinical pregnancy rate was significantly improved after LEI in both the randomized (relative risk, RR, 2.63, 95% CI 1.39-4.96, P=0.003) and non-randomized studies (RR 1.95, 95% CI 1.61-2.35, P<0.00001). The improvement did not reach statistical significance in the one randomized study which reported the live birth rate (RR 2.29, 95% CI 0.86-6.11). Robust randomized trials comparing a standardized protocol of LEI before IVF treatment with no intervention in a well-defined patient population are needed.

The search for a practice model to reduce miscarriage after assisted reproduction.

The analysis of 52,874 clinical pregnancies recorded on the Australian and New Zealand Assisted Reproduction Database (ANZARD) between 2004 and 2008 showed that maternal age and obstetrics history are closely related to the risk of miscarriage, and that the transfer of fresh embryos is associated with fewer miscarriages than transfer of frozen-thawed embryos. It also suggested a higher miscarriage rate is associated with the transfer of thawed blastocysts compared with transfer of thawed cleavage-stage embryos or the blastocysts that ensued from them. Therefore, the authors proposed a practice model of transferring fresh blastocysts and freezing of cleavage-stage embryos to reduce the miscarriage rate after assisted reproduction. This model may have practical limitation and would need validation in a randomized trial. Retrospective analysis of large national databases is useful in identifying trends and generating hypothesis, but evaluation of these hypotheses in randomized trials remains necessary for objective validation.

Reducing multiple pregnancies after assisted reproduction treatment: Québec says 'Yes, we can!'.

Multiple pregnancy (MP) is widely recognized as the single biggest risk to children born as a result of assisted reproduction treatment. There is an emerging trend in Europe and Canada to promote single-embryo transfer (SET). In this issue, Gleicher argues that twin pregnancies should not be seen as an unfavourable outcome of assisted reproduction treatment. He argues that SET policies 'make no sense' since they will aggravate already unsatisfactory population growth in some countries. He also argues that governmental intervention to impose SET policies, despite proving successful in reducing MP, are inappropriate. The overwhelming evidence in the literature indicates that his opinion is not supported by credible data. Views should be based on solid data rather than personal judgement. Governmental interventions to reduce twin pregnancies, as demonstrated previously in Belgium and now in Québec, have been successful. The risks of twin pregnancies are real and borne by women and children, not their doctors. Doctors managing infertile couples are no longer entitled to take risks with the health of the next generation.

Effect of androgen supplementation or modulation on ovarian stimulation outcome in poor responders: a meta-analysis.

Many trials have evaluated the use of androgen supplements and androgen-modulating agents to improve outcome of poor responders undergoing IVF treatment. This study conducted a systematic review and meta-analysis of controlled trials of androgen adjuvants (testosterone, dehydroepiandrostereone) and the androgen-modulating agent (letrozole) in poor responders undergoing IVF treatment. Searches were conducted on MEDLINE, EMBASE, Cochrane Library, ISRCTN Register and ISI proceedings. All randomized and non-randomized controlled trials were included. Study selection, quality appraisal and data extraction were performed independently and in duplicate. The main outcome measure was clinical pregnancy rate. The secondary outcome measures were dose and duration of gonadotrophin use, cycles cancelled before oocyte retrieval, oocytes retrieved and ongoing pregnancy rates. A total of 2481 cycles in women considered as poor responders undergoing IVF/intracytoplasmic sperm injection (ICSI) treatment were included in nine controlled trials. Meta-analyses of these studies did not show any significant difference in the number of oocytes retrieved and ongoing pregnancy/live-birth rates with androgen supplementation or modulation compared with the control groups. There is currently insufficient evidence from the few randomized controlled trials to support the use of androgen supplementation or modulation to improve live birth outcome in poor responders undergoing IVF/ICSI treatment.

The influence of delayed blastocyst formation on the outcome of frozen-thawed blastocyst transfer: a systematic review and meta-analysis.

BACKGROUND: There are conflicting results on whether the rate of blastocyst development before freezing influences the outcome of frozen-thawed blastocyst transfers. METHODS: We conducted a systematic review and meta-analysis of controlled studies to compare pregnancy outcomes following transfer of thawed blastocysts that were frozen either on Day 5 or Day 6 following fertilization in vitro. Searches were conducted on MEDLINE, EMBASE, Cochrane Library and Web of Science. Study selection and data extraction were conducted independently by two reviewers. The Newcastle-Ottawa Quality Assessment Scale was used for quality assessment. RESULTS: We identified 15 controlled studies comprising 2502 frozen-thawed transfers involving blastocysts that were either frozen on Day 5 or Day 6. Meta-analysis of these studies showed significantly higher clinical pregnancy rate [relative risk (RR) = 1.14, 95% confidence interval (CI): 1.03-1.26, P = 0.01] and ongoing pregnancy/live birth rate (RR = 1.15, 95% CI: 1.01-1.30, P = 0.03) with Day 5 compared with Day 6 frozen-thawed blastocyst transfers. Sensitivity analysis of those studies where blastocysts frozen on Day 5 or Day 6 were at the same stage of development showed no significant difference in the clinical pregnancy rate (RR = 1.07, 95% CI: 0.87-1.33, P = 0.51) and ongoing pregnancy/live birth rate (RR = 1.08, 95% CI: 0.92-1.27, P = 0.36). CONCLUSION: Slower developing blastocysts cryopreserved on Day 6 but at the same stage of development as those developing to the blastocyst stage on Day 5 have similar clinical pregnancy and ongoing pregnancy/live birth rates following frozen-thawed blastocyst transfers.

Funding and public reporting strategies for reducing multiple pregnancy from fertility treatments.

The health of children born through assisted reproductive technologies (ART) is particularly vulnerable to policy decisions and market forces that play out before they are even conceived. ART treatment is costly, and public and third-party funding varies significantly between and within countries, leading to considerable variation in consumer affordability globally. These relative cost differences affect not only who can afford to access ART treatment, but also how ART is practiced in terms of embryo transfer practices, with less affordable treatment creating a financial incentive to transfer more than one embryo to maximize the pregnancy rates in fewer cycles. One mechanism for reducing the burden of excessive multiple pregnancies is to link insurance coverage to the number of embryos that can be transferred; another is to combine supportive funding with patient and clinician education and public reporting that emphasizes a "complete" ART cycle (all embryo transfers associated with an egg retrieval) and penalizes multiple embryo transfers. Improving funding for fertility services in a way that respects clinician and patient autonomy and allows patients to undertake a sufficient number of cycles to minimize moral hazard improves outcomes for mothers and babies while reducing the long-term economic burden associated with fertility treatments.

Age-specific serum FSH concentrations and their correlation with the outcome of ovarian stimulation for IVF.

The aim of this study was to investigate whether age-specific FSH concentration can be a predictor of the outcome of ovarian stimulation in women undergoing IVF, with various basal FSH (bFSH) concentrations but within the normal range, i.e. < or = 9.5 lU/l. A total of 1373 women undergoing their first NF cycle over a 5-year period were included in this retrospective cohort study. Patients were grouped according to age, and within each age range, patients were grouped into bFSH quartiles. The primary outcome measure was oocyte yield, and secondary outcome measures included number of normally fertilized oocytes (2PN), number of embryos transferred and frozen, as well as implantation, biochemical, and clinical pregnancy rates. In all study groups (25-29; 30-34 and 35-39 years), women with low bFSH concentrations had significantly more oocytes retrieved (P = 0.003; P < 0.0001 and P = 0.0001 respectively), and more normally fertilized 2PN embryos (P = 0.03; P < 0.0001 and P = 0.001 respectively) than those of the same age with 'high' normal bFSH concentrations. Although there was no significant difference in the secondary outcome measures, these were generally more favourable in patients with 'low' age-specific bFSH concentrations. The findings of this study suggest that age-specific FSH testing can serve as a good predictor of the oocyte yield in women with normal bFSH concentrations undergoing IVF.

The impact of acupuncture on assisted reproductive technology outcome.

PURPOSE OF REVIEW: To evaluate the impact of acupuncture on the outcome of in-vitro fertilization treatment using data from published randomized studies. The main outcome measure of interest is the clinical pregnancy rate. RECENT FINDINGS: Fourteen relevant trials including 2870 women were examined. Significant clinical and statistical heterogeneity were encountered among the studies. Five trials (n = 877) evaluated in-vitro fertilization outcome when acupuncture was performed around the time of oocyte retrieval and found no difference in the clinical pregnancy rate between the two groups [relative risk (RR) = 1.06, 95% confidence interval (CI) 0.82-1.37, P = 0.65]. Likewise, nine trials (n = 1993) reported in-vitro fertilization outcome when acupuncture was performed around the time of embryo transfer and showed no significant difference in the clinical pregnancy rate (RR = 1.16, 95% CI 0.92-1.48, P = 0.22). SUMMARY: Currently available literature does not provide sufficient evidence that adjuvant acupuncture, whether performed at the time of oocyte retrieval or embryo transfer, improves in-vitro fertilization outcome. On the basis of this evidence, acupuncture should not be recommended during in-vitro fertilization to increase its success rate.

Infertility information on the World Wide Web: a cross-sectional survey of quality of infertility information on the internet in the UK.

BACKGROUND: The internet is a frequently used source of information for infertile couples. Previous studies suggested that the quality of health information on the internet is poor. The aim of this study was to assess the quality of websites providing information on infertility and its management in the UK. Differences between website types and affiliations were assessed. METHODS: A Google search for the keyword 'infertility' was performed and 107 relevant websites were identified and categorized by type. Websites were assessed for credibility, accuracy and ease of navigation using predefined criteria. RESULTS: The total scores for all types of websites were low, particularly in the accuracy category. Websites affiliated to the UK National Health Service (NHS) scored higher than those affiliated to private fertility clinics and other clinics providing non-conventional fertility treatment. Specifically, NHS websites were more likely to report success rates (92.9% versus 60% and 0%, P < or = 0.05) and display information about their sources of funding (85.7% versus 15% and 14.8%, P < or = 0.0001). CONCLUSIONS: Internet resources available to infertile patients are variable. Differences in the quality of infertility information exist between the different types of websites.

Antral follicle count at down-regulation and prediction of poor ovarian response.

The aim of this study was to assess the accuracy of antral follicle count (AFC) performed after pituitary down-regulation (dAFC) in predicting poor ovarian response and the influence of using different thresholds of follicle size and count on its accuracy. Using three definitions of follicle size, three dAFC were determined for every patient in a consecutive cohort of 148 IVF cycles. The performance of the dAFC in predicting poor ovarian response (as expressed by area under the curve; AUC) for follicle size definitions of 2-5, 2-8, 2-10 mm, was not significantly different (AUC 0.80, 0.80, 0.79, respectively). Multilevel likelihood ratio for dAFC thresholds of 20 were 5.43 (95% confidence interval 0.81-36.6), 3.06 (1.54-6.06), 1.63 (0.74-3.62) and 0.37 (0.19-0.75) with post-test probabilities of poor ovarian response of 50%, 36%, 23% and 6%, respectively, for a pretest probability of 15.5% for poor ovarian response. The single most important predictor of ovarian response was dAFC. The highest predictive performance was obtained in a model combining age and body mass index and dAFC (AUC = 0.82) showing only marginal improvement over dAFC alone. In conclusion, the performance of dAFC is the same regardless of the definition used for the size of antral follicles.

Outpatient hysteroscopy and subsequent IVF cycle outcome: a systematic review and meta-analysis.

A systematic review of studies evaluating the influence of outpatient (office) hysteroscopy on the outcome of the subsequent IVF cycle was conducted. MEDLINE, EMBASE, the Cochrane Library, National Research Register, ISI Conference Proceedings, ISRCTN Register and Meta-register were searched for randomized controlled trials (up to July 2007). All trials comparing the outcome of IVF treatment performed in patients who had outpatient hysteroscopy in the cycle preceding their IVF treatment with a control group in which hysteroscopy was not performed were included. Study selection, quality appraisal and data extraction were performed independently and in duplicate. Study authors were contacted for additional information. The main outcome measure was pregnancy rate. In total, 1691 participants were included in two randomized (n = 941) and three non-randomized controlled studies (n = 750). The quality of the studies was variable. Meta-analyses of the results of five studies showed evidence of benefit from outpatient hysteroscopy in improving the pregnancy rate in the subsequent IVF cycle (pooled relative risk = 1.75, 95% CI 1.51-2.03). The evidence from randomized trials was consistent with that from non-randomized controlled studies. Future robust randomized trials comparing outpatient hysteroscopy or mini-hysteroscopy with no intervention before IVF treatment would be a useful addition to further guide clinical practice.