Congenital Uterine Malformation by Experts (CUME): diagnostic criteria for T-shaped uterus.

OBJECTIVES: To identify uterine measurements that are reliable and accurate to distinguish between T-shaped and normal/arcuate uterus, and define T-shaped uterus, using Congenital Uterine Malformation by Experts (CUME) methodology, which uses as reference standard the decision made most often by several independent experts. METHODS: This was a prospectively planned multirater reliability/agreement and diagnostic accuracy study, performed between November 2017 and December 2018, using a sample of 100 three-dimensional (3D) datasets of different uteri with lateral uterine cavity indentations, acquired from consecutive women between 2014 and 2016. Fifteen representative experts (five clinicians, five surgeons and five sonologists), blinded to each others' opinions, examined anonymized images of the coronal plane of each uterus and provided their independent opinion as to whether it was T-shaped or normal/arcuate; this formed the basis of the CUME reference standard, with the decision made most often (i.e. that chosen by eight or more of the 15 experts) for each uterus being considered the correct diagnosis for that uterus. Two other experienced observers, also blinded to the opinions of the other experts, then performed independently 15 sonographic measurements, using the original 3D datasets of each uterus. Agreement between the diagnoses made by the 15 experts was assessed using kappa and percent agreement. The interobserver reliability of measurements was assessed using the concordance correlation coefficient (CCC). The diagnostic test accuracy was assessed using the area under the receiver-operating-characteristics curve (AUC) and the best cut-off value was assessed by calculating Youden's index, according to the CUME reference standard. Sensitivity, specificity, negative and positive likelihood ratios (LR- and LR+) and post-test probability were calculated. RESULTS: According to the CUME reference standard, there were 20 T-shaped and 80 normal/arcuate uteri. Individual experts recognized between 5 and 35 (median, 19) T-shaped uteri on subjective judgment. The agreement among experts was 82% (kappa = 0.43). Three of the 15 sonographic measurements were identified as having good diagnostic test accuracy, according to the CUME reference standard: lateral indentation angle (AUC = 0.95), lateral internal indentation depth (AUC = 0.92) and T-angle (AUC = 0.87). Of these, T-angle had the best interobserver reproducibility (CCC = 0.87 vs 0.82 vs 0.62 for T-angle vs lateral indentation depth vs lateral indentation angle). The best cut-off values for these measurements were: lateral indentation angle ≤ 130° (sensitivity, 80%; specificity, 96%; LR+, 21.3; LR-, 0.21), lateral indentation depth ≥ 7 mm (sensitivity, 95%; specificity, 77.5%; LR+, 4.2; LR-, 0.06) and T-angle ≤ 40° (sensitivity, 80%; specificity, 87.5%; LR+, 6.4; LR-, 0.23). Most of the experts diagnosed the uterus as being T-shaped in 0% (0/56) of cases when none of these three criteria was met, in 10% (2/20) of cases when only one criterion was met, in 50% (5/10) of cases when two of the three criteria were met, and in 93% (13/14) of cases when all three criteria were met. CONCLUSIONS: The diagnosis of T-shaped uterus is not easy; the agreement among experts was only moderate and the judgement of individual experts was commonly insufficient for accurate diagnosis. The three sonographic measurements with cut-offs that we identified (lateral internal indentation depth ≥ 7 mm, lateral indentation angle ≤ 130° and T-angle ≤ 40°) had good diagnostic test accuracy and fair-to-moderate reliability and, when applied in combination, they provided high post-test probability for T-shaped uterus. In the absence of other anomalies, we suggest considering a uterus to be normal when none or only one criterion is met, borderline when two criteria are met, and T-shaped when all three criteria are met. These three CUME criteria for defining T-shaped uterus may aid in determination of its prevalence, clinical implications and best management and in the assessment of post-surgical morphologic outcome. The CUME definition of T-shaped uterus may help in the development of interventional randomized controlled trials and observational studies and in the diagnosis of uterine morphology in everyday practice, and could be adopted by guidelines on uterine anomalies to enrich their classification systems. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Septate uterus according to ESHRE/ESGE, ASRM and CUME definitions: association with infertility and miscarriage, cost and warnings for women and healthcare systems.

OBJECTIVES: To estimate the differences in frequency of diagnosis of septate uterus using three different definitions and determine whether these differences are significant in clinical practice, and to examine the association between diagnosis of septate uterus, using each of the three definitions, and infertility and/or previous miscarriage as well as the cost of allocation to surgery. METHODS: This was a secondary analysis of data from a prospective study of 261 consecutive women of reproductive age attending a private clinic focused on the diagnosis and treatment of congenital uterine malformations. Reanalysis of the datasets was performed according to three different means of defining septate uterus: following the recommendations of the American Society for Reproductive Medicine (ASRM), a 2016 update of those of the American Fertility Society from 1988 (ASRM-2016: internal fundal indentation depth ≥ 1.5 cm, angle of internal indentation < 90° and external indentation depth < 1 cm); following the recommendations of the European Society of Human Reproduction and Embryology/European Society for Gynaecological Endoscopy (ESHRE/ESGE), published in 2013 and reaffirmed in 2016 (ESHRE/ESGE-2016: internal fundal/uterine indentation depth > 50% of uterine-wall thickness and external indentation depth < 50% of uterine-wall thickness, with uterine-wall thickness measured above interostial/intercornual line); and using a definition published last year which was based on the decision made most often by a group of experts (Congenital Uterine Malformation by Experts; CUME) (CUME-2018: internal fundal indentation depth ≥ 1 cm and external fundal indentation depth < 1 cm). We compared the rate of diagnosis of septate uterus using each of these three definitions and, for each, we estimated the association between the diagnosis and infertility and/or previous miscarriage, and anticipated the costs associated with their implementation using a guesstimation method. RESULTS: Although 32.6% (85/261) of the subjects met the criteria for one of the three definitions of septate uterus, only 2.7% (7/261) of them were defined as having septate uterus according to all three definitions. We diagnosed significantly more cases of septate uterus using ESHRE/ESGE-2016 than using ASRM-2016 (31% vs 5%, relative risk (RR) = 6.7, P < 0.0001) or CUME-2018 (31% vs 12%, RR = 2.6, P < 0.0001) criteria. We also observed frequent cases that could not be classified definitively by ASRM-2016 (gray zone: neither normal/arcuate nor septate; 6.5%). There were no significant differences (P > 0.05) in the prevalence of septate uterus in women with vs those without infertility according to ASRM-2016 (5% vs 4%), ESHRE/ESGE-2016 (35% vs 28%) or CUME-2018 (11% vs 12%). Septate uterus was diagnosed significantly more frequently in women with vs those without previous miscarriage according to ASRM-2016 (11% vs 3%; P = 0.04) and CUME-2018 (22 vs 10%; P = 0.04), but not according to ESHRE/ESGE-2016 (42% vs 28%; P = 0.8) criteria. Our calculations showed that global costs to the healthcare system would be highly dependent on the criteria used in the clinical setting to define septate uterus, with the costs associated with the ESHRE/ESGE-2016 definition potentially being an extra US$ 100-200 billion over 5 years in comparison to ASRM-2016 and CUME-2018 definitions. CONCLUSIONS: The prevalence of septate uterus according to ESHRE/ESGE-2016, ASRM-2016 and CUME-2018 definitions differs considerably. An important limitation of the ASRM classification, which needs to be addressed, is the high proportion of unclassifiable cases originally named, by us, the 'gray zone'. The high rate of overdiagnosis of septate uterus according to ESHRE/ESGE-2016 may lead to unnecessary surgery and therefore unnecessary risk in these women and may impose a considerable financial burden on healthcare systems. Efforts to define clinically meaningful and universally applicable criteria for the diagnosis of septate uterus should be encouraged. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Útero septo según las definiciones de ESHRE/ESGE, ASRM y CUME: la relación con la infertilidad y el aborto espontáneo, el costo y advertencias para las mujeres y los sistemas de salud OBJETIVO: Evaluar el rendimiento de la velocidad sistólica máxima de la arteria cerebral media fetal (MCA-PSV, por sus siglas en inglés) ≥1,5 múltiplos de la mediana (MdM) para la predicción de la anemia moderada-severa en fetos sometidos a transfusión y no sometidos. MÉTODOS: Se realizó una búsqueda sistemática para identificar estudios observacionales relevantes reportados en el período 2008-2018 que evaluaron el rendimiento de la MCA-PSV, utilizando un umbral de 1,5MdM para la predicción de la anemia fetal. El diagnóstico de la anemia fetal mediante la toma de muestras de sangre fue el estándar de referencia. Se utilizaron modelos de efectos aleatorios para la elaboración de una curva jerárquica resumen de las características operativas del receptor (hSROC, por sus siglas en inglés). Se realizaron análisis de subgrupos y metarregresión, según el número de transfusiones intrauterinas previas. RESULTADOS: En el metaanálisis se incluyeron doce estudios y 696 fetos. El área bajo la curva (ABC) hSROC para la anemia moderada-severa fue del 83%. La sensibilidad y especificidad agrupadas (IC 95%) fueron del 79% (70-86%) y 73% (62-82%), respectivamente, y los cocientes de verosimilitud positivos y negativos fueron 2,94 (IC 95%: 2,13-4,00) y 0,272 (IC 95%: 0,188-0,371). Cuando solo se consideraron los fetos no sometidos a transfusión, la predicción mejoró, pues se logró un ABC del 87%, una sensibilidad del 86% (IC 95%: 75-93%) y una especificidad del 71% (IC 95%: 49-87%). Se observó una disminución en la sensibilidad de la predicción de la anemia moderada-severa mediante la MCA-PSV ≥1.5MdM (estimación, -5,5% (IC 95%: -10,7 a -0,3%), P=0,039) en función del aumento del número de transfusiones previas. CONCLUSIONES: El uso de la MCA-PSV ≥1.5MdM para la predicción de la anemia moderada-severa en fetos no sometidos a transfusión muestra una precisión moderada (86% de sensibilidad y 71% de especificidad), que disminuye con el aumento del número de transfusiones intrauterinas.

Congenital Uterine Malformation by Experts (CUME): better criteria for distinguishing between normal/arcuate and septate uterus?

OBJECTIVES: To assess the level of agreement between experts in distinguishing between septate and normal/arcuate uterus using their subjective judgment when reviewing the coronal view of the uterus from three-dimensional ultrasound. Another aim was to determine the interobserver reliability and diagnostic test accuracy of three measurements suggested by recent guidelines, using as reference standard the decision made most often by experts (Congenital Uterine Malformation by Experts (CUME)). METHODS: Images of the coronal plane of the uterus from 100 women with suspected fundal internal indentation were anonymized and provided to 15 experts (five clinicians, five surgeons and five sonologists). They were instructed to indicate whether they believed the uterus to be normal/arcuate (defined as normal uterine morphology or not clinically relevant degree of distortion caused by internal indentation) or septate (clinically relevant degree of distortion caused by internal indentation). Two other observers independently measured indentation depth, indentation angle and indentation-to-wall-thickness (I:WT) ratio. The agreement between experts was assessed using kappa, the interobserver reliability was assessed using the concordance correlation coefficient (CCC), the diagnostic test accuracy was assessed using the area under the receiver-operating characteristics curve (AUC) and the best cut-off value was assessed using Youden's index, considering as the reference standard the choice made most often by the experts (CUME). RESULTS: There was good agreement between all experts (kappa, 0.62). There were 18 septate and 82 normal/arcuate uteri according to CUME; European Society of Human Reproduction and Embryology (ESHRE)-European Society for Gynaecological Endoscopy (ESGE) criteria (I:WT ratio > 50%) defined 80 septate and 20 normal/arcuate uteri, while American Society for Reproductive Medicine (ASRM) criteria defined five septate (depth > 15 mm and angle < 90°), 82 normal/arcuate (depth < 10 mm and angle > 90°) and 13 uteri that could not be classified (referred to as the gray-zone). The agreement between ESHRE-ESGE and CUME was 38% (kappa, 0.1); the agreement between ASRM criteria and CUME for septate was 87% (kappa, 0.39), and considering both septate and gray-zone as septate, the agreement was 98% (kappa, 0.93). Among the three measurements, the interobserver reproducibility of indentation depth (CCC, 0.99; 95% CI, 0.98-0.99) was better than both indentation angle (CCC, 0.96; 95% CI, 0.94-0.97) and I:WT ratio (CCC, 0.92; 95% CI, 0.90-0.94). The diagnostic test accuracy of these three measurements using CUME as reference standard was very good, with AUC between 0.96 and 1.00. The best cut-off values for these measurements to define septate uterus were: indentation depth ≥ 10 mm, indentation angle < 140° and I:WT ratio > 110% . CONCLUSIONS: The suggested ESHRE-ESGE cut-off value overestimates the prevalence of septate uterus while that of ASRM underestimates this prevalence, leaving in the gray-zone most of the uteri that experts considered as septate. We recommend considering indentation depth ≥ 10 mm as septate, since the measurement is simple and reliable and this criterion is in agreement with expert opinion. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Clomiphene citrate and letrozole to reduce follicle-stimulating hormone consumption during ovarian stimulation: systematic review and meta-analysis.

OBJECTIVE: To assess the available evidence comparing effectiveness of ovarian stimulation (OS) using clomiphene citrate (CC) and/or letrozole (LTZ) to reduce follicle-stimulating hormone (FSH) consumption compared with standard OS. METHODS: We performed a systematic review and meta-analysis of randomized controlled trials that compared reproductive outcomes following in-vitro fertilization. We searched 11 electronic databases and hand-searched the reference lists of included studies and related reviews. We stratified the results, separating studies according to the oral agent used (CC or LTZ) and the characteristics of the included women (expected poor ovarian response or other women). When combining the results of the included studies, we assessed the relative risk (RR) for live birth, clinical pregnancy, miscarriage and cycle cancelation, the Peto odds ratio (OR) for ovarian hyperstimulation syndrome (OHSS) and mean difference (MD) for the number of oocytes retrieved and FSH consumption. RESULTS: A total of 22 studies were included in the review. Considering women with expected poor ovarian response, the available evidence suggested that using CC to reduce FSH consumption during OS provided similar rates of live birth (RR, 0.9 (95% CI, 0.6-1.2), moderate-quality evidence) and clinical pregnancy (RR, 1.0 (95% CI, 0.8-1.4), moderate-quality evidence); the use of LTZ did not cause a relevant change in the number of oocytes retrieved (MD, -0.4 (95% CI, -0.9 to 0.1), high-quality evidence). Considering the studies evaluating other women, the available evidence suggested that using CC to reduce FSH consumption during OS reduced the number of oocytes retrieved (MD, -4.6 (95% CI, -6.1 to -3.0), high-quality evidence) and risk of OHSS (Peto OR, 0.2 (95% CI, 0.1-0.3), moderate-quality evidence), while results were similar for rates of live birth (RR, 0.9 (95% CI, 0.7-1.1), moderate-quality evidence) and clinical pregnancy (RR, 1.0 (95% CI, 0.8-1.1), high-quality evidence). The quality of the evidence was low or very low for other outcomes. CONCLUSION: The use of CC to reduce FSH consumption in women with expected poor ovarian response has the advantage of providing similar reproductive outcomes with reduced costs. For the other women, the use of CC for reducing FSH consumption has the additional advantage of reducing OHSS, but also reduces the total number of oocytes retrieved. More studies are needed to evaluate the effect of LTZ for the same purpose. Future studies should focus on cumulative pregnancy per oocyte retrieval, patient dissatisfaction and agreement to repeat the cycle if not pregnant, which are important outcomes for clinical decisions. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Blastocyst vs cleavage-stage embryo transfer: systematic review and meta-analysis of reproductive outcomes.

OBJECTIVES: Blastocyst transfer in assisted reproduction techniques could be advantageous because the timing of exposure of the embryo to the uterine environment is more analogous to a natural cycle and permits embryo self-selection after activation of the embryonic genome on day 3. Conversely, the in-vitro environment is likely to be inferior to that in vivo, and in-vitro culture beyond embryonic genomic activation could potentially harm the embryo. Our objective was to identify, appraise and summarize the available evidence comparing the effectiveness of blastocyst vs cleavage-stage embryo transfer. METHODS: This was a systematic review and meta-analysis of randomized controlled trials (RCTs) comparing the transfer of blastocysts (days 5-6) with the transfer of cleavage-stage embryos (days 2-3) in women undergoing in-vitro fertilization or intracytoplasmic sperm injection. The last electronic searches were run on 1 August 2016. Abstracts and studies with a mean difference between the two study groups of > 0.5 for the number of embryos transferred were excluded. RESULTS: We screened 1187 records and assessed 33 potentially eligible studies. Twelve studies were included, comprising a total of 1200 women undergoing blastocyst transfer and 1218 undergoing cleavage-stage embryo transfer. We observed low-quality evidence of no significant difference of blastocyst transfer on live birth/ongoing pregnancy (relative risk (RR), 1.11 (95% CI, 0.92-1.35), 10 RCTs, 1940 women, I2 = 54%), clinical pregnancy (RR, 1.10 (95% CI, 0.93-1.31), 12 RCTs, 2418 women, I2 = 64%), cumulative pregnancy (RR, 0.89 (95% CI, 0.67-1.16), four RCTs, 524 women, I2 = 63%) and miscarriage (RR, 1.08 (95% CI, 0.74-1.56), 10 RCTs, 763 pregnancies, I2 = 0%). There was moderate-quality evidence of a decrease in the number of women with surplus embryos after the blastocyst-stage embryo transfer (RR, 0.78 (95% CI, 0.66-0.91)). Overall, the quality of the evidence was limited by the quality of the included studies and by unexplained inconsistency across studies. CONCLUSIONS: Current evidence shows no superiority of blastocyst compared with cleavage-stage embryo transfer in clinical practice. As the quality of the evidence for the primary outcomes is low, additional well-designed RCTs are still needed before robust conclusions can be drawn. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Obstetrical and perinatal outcomes following blastocyst transfer compared to cleavage transfer: a systematic review and meta-analysis.

STUDY QUESTION: Is blastocyst transfer safe when compared to cleavage stage embryo transfer regarding obstetric and perinatal outcomes? SUMMARY ANSWER: The clinical equipoise between blastocyst and cleavage stage embryo transfer remains as the evidence associating blastocyst transfer with some adverse perinatal outcomes is of low/very low quality. WHAT IS KNOWN ALREADY: Extended embryo culture to the blastocyst stage provides some theoretical advantages and disadvantages. While it permits embryo self-selection, it also exposes those embryos to possible harm due to the in vitro environment. Both effectiveness and safety should be weighed to permit evidence-based decisions in clinical practice. STUDY DESIGN, SIZE, DURATION: This is a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies reporting perinatal outcomes for singletons comparing the deliveries resulting from blastocyst and cleavage stage embryo transfer. Observational studies were included because the primary outcomes, perinatal mortality and birth defects, are rare and require a large number of participants (>50 000) to be properly assessed. The last electronic searches were last run on 11 March 2016. PARTICIPANTS/MATERIALS, SETTING, METHOD: There were 12 observational studies encompassing 195 325 singleton pregnancies included in the study. No RCT reported the studied outcomes. The quality of the included studies was evaluated according to the Newcastle-Ottawa Scale and the quality of the evidence was evaluated according to GRADE criteria. MAIN RESULTS AND THE ROLE OF CHANCE: Blastocyst stage transfer was associated with increased risks of preterm birth (<37 weeks), very preterm birth (<32 weeks), large for gestational age and perinatal mortality, although the latter was only identified from one study. Conversely, blastocyst stage transfer was associated with a decrease in the risks of small for gestational age and vanishing twins, although the latter was reported by only one study. LIMITATIONS, REASONS FOR CAUTION: The observational nature of the included studies and some inconsistency and imprecision in the analysis contributed to decreasing our confidence in the estimates. WIDER IMPLICATIONS OF THE FINDINGS: Due to the overall low quality of available evidence, the clinical equipoise between cleavage stage and blastocyst transfer remains. More large well-conducted studies are needed to clarify the potential risks and benefits of blastocyst transfer. As this review was initiated to support global recommendations on best practice, and in light of the challenges in lower resource settings to offer extended culture to blastocyst stage, it is critical to take into consideration these obstetric and neonatal outcomes in order to ensure any recommendation will not result in the overburdening of existing maternal and child health care systems and services. STUDY FUNDING/COMPETING INTERESTS: No external funding was either sought or obtained for this study. The authors have no competing interests to declare. PROSPERO REGISTRATION NUMBER: CRD42015023910.

GnRH agonist during luteal phase in women undergoing assisted reproductive techniques: systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To identify, evaluate and summarize the available evidence regarding the effectiveness and safety of administering a gonadotropin releasing hormone (GnRH) agonist during the luteal phase in women undergoing assisted reproductive techniques. METHODS: In this systematic review and meta-analysis, we searched for randomized controlled trials (RCTs) comparing the addition of a GnRH agonist during the luteal phase, compared with standard luteal-phase support. We searched seven electronic databases and hand-searched the reference lists of included studies and related reviews. Our primary outcome was live birth or ongoing pregnancy per randomized woman. Our secondary outcomes were clinical pregnancy per randomized woman, miscarriage per clinical pregnancy, adverse perinatal outcome and congenital malformations. RESULTS: The evidence from eight studies examining 2776 women showed a relative risk (RR) for live birth or ongoing pregnancy of 1.26 (95% CI, 1.04-1.53; I(2) = 58%). Sensitivity analysis when excluding the studies that did not report live birth and those at high risk of bias resulted in one study examining 181 women with an RR of 1.07 (95% CI, 0.73-1.58). Subgroup analysis separating the studies by single/multiple doses of GnRH agonists or by ovarian stimulation with GnRH agonist/antagonist was unable to explain the observed heterogeneity. The quality of the evidence was deemed to be very low: it was downgraded because of the limitation of the included studies, imprecision, inconsistency across the studies' results, and suspicion of publication bias. None of the included studies reported adverse perinatal outcomes or congenital malformations. CONCLUSIONS: There is evidence that adding GnRH agonist during the luteal phase improves the likelihood of ongoing pregnancy. However, this evidence is of very low quality and there is no evidence for adverse perinatal outcome and congenital malformations. We therefore believe that including this intervention in clinical practice would be premature.

High miscarriage rate in women treated with Essure® for hydrosalpinx before embryo transfer: a systematic review and meta-analysis.

OBJECTIVES: Essure® has been tested as an alternative treatment for hydrosalpinx before embryo transfer (ET) in women undergoing assisted reproduction techniques. However, the persistence of a foreign body inside the uterine cavity might have a negative impact on the outcome of pregnancy. The present systematic review aimed at identifying, appraising and summarizing the available evidence regarding the effectiveness and safety of using Essure prior to ET for women with hydrosalpinx. METHODS: We searched for studies in PubMed, Scopus, CENTRAL, Web of Science and ClinicalTrials.gov and the reference lists of eligible studies. All studies including at least 10 women with hydrosalpinx who received Essure, any other intervention or no treatment prior to ET were considered eligible. Study selection, data extraction and evaluation of the risk of bias were performed independently by two authors. Study outcomes were miscarriage per clinical pregnancy, singleton preterm birth per singleton live birth and live birth/ongoing pregnancy and clinical pregnancy per ET. The pooled results for each outcome and intervention were summarized as proportions with their respective 95% CIs, using a random-effects model. RESULTS: Our electronic search of databases was performed on 7 November 2015, and 26 studies with 43 study arms were considered eligible: eight study arms evaluating Essure; seven assessing tubal aspiration; seven appraising effects of no treatment; 12 evaluating salpingectomy; two assessing tubal division; and seven evaluating tubal occlusion. When compared with women who had no intervention, women with Essure had a higher clinical pregnancy rate per ET (36% (95% CI, 0-43%) vs 13% (95% CI, 9-17%)). When compared with women who had other interventions, women with Essure had a higher miscarriage rate per clinical pregnancy (38% (95% CI, 27-49%) vs 15% (95% CI, 10-19%)). CONCLUSIONS: The available evidence suggests that, although Essure prior to ET in women with hydrosalpinx improves the chance of achieving a clinical pregnancy compared with no intervention, it is associated with a higher rate of miscarriage when compared with the other interventions. Although this evidence is based on observational studies, we believe that salpingectomy should be the first option for women who are eligible for videolaparoscopy. However, it is still premature to make recommendations for women who are not eligible for surgery, and randomized controlled trials are needed to clarify which is the best treatment alternative in such a scenario. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Strategies for improving outcome of assisted reproduction in women with polycystic ovary syndrome: systematic review and meta-analysis.

OBJECTIVES: To identify, appraise and summarize the current evidence regarding the efficacy of strategies aimed at improving assisted reproductive techniques in women with polycystic ovary syndrome (PCOS). METHODS: A comprehensive literature search of the standard medical databases was performed. The last electronic search was run in July 2015. The primary outcome measures were live birth/ongoing pregnancy and ovarian hyperstimulation syndrome (OHSS). The secondary outcome measures were clinical pregnancy and miscarriage. RESULTS: We screened 1021 records and completely assessed 173, finally including 66 studies in the quantitative analysis. Many different interventions were assessed, however the overall quality of the studies was low. We observed moderate-quality evidence that there is no clinically relevant difference in live birth/ongoing pregnancy rates (relative risk (RR), 0.95 (95% CI, 0.84-1.08)), or clinical pregnancy (RR, 1.02 (95% CI, 0.91-1.15)) when comparing antagonist and agonist protocols for ovarian stimulation. Additionally, we found low-quality evidence that metformin improves live birth/ongoing pregnancy (RR, 1.28 (95% CI, 1.01-1.63)) and clinical pregnancy rates (RR, 1.26 (95% CI, 1.04-1.53)) when compared with placebo or no intervention. We further found low-quality evidence that there is no clinically relevant difference in live birth/ongoing pregnancy rates (RR, 1.03 (95% CI, 0.80-1.34)) and clinical pregnancy rates (RR, 0.99 (95% CI, 0.81-1.22)) when comparing human menopausal gonadotropin for inducing ovulation and artificial preparation with estradiol valerate for endometrial preparation for frozen embryo transfer (FET). Low-quality evidence suggests that mannitol compared with no intervention (RR, 0.54 (95% CI, 0.39-0.77)) and antagonist protocols compared with agonist protocols (RR, 0.63 (95% CI, 0.49-0.80)) reduce rates of OHSS. CONCLUSION: There is low- to moderate-quality evidence suggesting that antagonist protocols are preferable to agonist ones, because they reduce the incidence of OHSS without interfering with clinical pregnancy and live birth for women with PCOS. Additionally there is low-quality evidence pointing to a benefit of metformin supplementation on clinical pregnancy and live birth; and that ovulation induction and administration of estradiol seem to be equally effective for endometrial preparation before FET for women with PCOS. For all other interventions, the evidence is of very low quality, not allowing any meaningful conclusions to be drawn. Estrategias para mejorar el resultado de la reproducción asistida en mujeres con síndrome de ovario poliquístico: revisión sistemática y metaanálisis RESUMEN OBJETIVOS: Identificar, evaluar y resumir la evidencia actual sobre la eficacia de las estrategias para mejorar las técnicas de reproducción asistida en mujeres con síndrome de ovario poliquístico (SOP). MÉTODOS: Se realizó una búsqueda exhaustiva de literatura en las bases de datos médicas estándar. La última búsqueda electrónica se realizó en julio de 2015. Las medidas de resultado primarias fueron los nacimientos vivos/embarazos en curso y el síndrome de hiperestimulación ovárica (SHO). Las medidas de resultado secundarias fueron el embarazo confirmado ecográficamente y el aborto. RESULTADOS: Se cribaron 1021 registros, de los que se evaluaron por completo 173, para finalmente incluir 66 estudios en el análisis cuantitativo. Aunque se evaluaron muchas intervenciones diferentes, en general la calidad de los estudios fue baja. Se observó evidencia de calidad moderada de que no hay diferencias relevantes clínicamente en las tasas de nacimientos vivos/embarazos en curso (riesgo relativo (RR): 0,95 (IC 95%, 0,84-1,08)), o de embarazos confirmados ecográficamente (RR: 1,02 (IC 95%, 0,91-1,15)), cuando se comparan los protocolos de antagonistas y agonistas para la estimulación ovárica. Además, se encontró evidencia de baja calidad en que la metformina mejora las tasas de nacimientos vivos/embarazos en curso (RR: 1,28 (IC 95%, 1,01-1,63)) y de embarazos confirmados ecográficamente (RR: 1,26 (IC 95%, 1,04-1,53)) en comparación con un placebo o la no intervención. Se encontró también evidencia de baja calidad en que no hay diferencias relevantes clínicamente en las tasas de nacimientos vivos/embarazos en curso (RR: 1,03 (IC 95%, 0,80-1,34)) y las tasas de embarazos confirmados ecográficamente (RR: 0,99 (IC 95%, 0.81-1,22)) al comparar la gonadotropina menopáusica humana para la inducción de la ovulación y la preparación artificial con el valerato de estradiol para preparar el endometrio para la transferencia de embriones congelados (TEC). La baja calidad de la evidencia sugiere que el manitol, en comparación con la no intervención (RR: 0,54 (IC 95%, 0,39-0,77)), y los protocolos de antagonistas, en comparación con los protocolos de agonistas (RR: 0,63 (IC 95%, 0,49-0,80)), reducen las tasas de SHO. CONCLUSIÓN: Hay evidencia de calidad baja a moderada que sugiere que los protocolos de antagonistas son preferibles a los de agonistas, ya que reducen la tasa de SHO sin interferir con el embarazo confirmado ecográficamente y los nacimientos vivos en las mujeres con SOP. Además, existe evidencia de baja calidad que indica un beneficio del uso de metformina como aporte suplementario en embarazos confirmados ecográficamente y en nacimientos vivos; y que la inducción de la ovulación y la administración de estradiol parecen ser igualmente eficaces para la preparación del endometrio antes de la TEC en mujeres con SOP. Para el resto de procedimientos, la evidencia es de muy baja calidad, y por ello no permite extraer conclusiones importantes.

Dydrogesterone vs progesterone for luteal-phase support: systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: To compare the effects of dydrogesterone and progesterone for luteal-phase support (LPS) in women undergoing assisted reproductive techniques (ART). METHODS: We performed a systematic review to identify relevant randomized controlled trials (RCTs) by searching the following electronic databases: Cochrane CENTRAL, PubMed, Scopus, Web of Science, ClinicalTrials.gov, ISRCTN Registry and WHO ICTRP. RESULTS: The last search was performed in October 2015. Eight RCTs were considered eligible and were included in the review and meta-analyses. There was no relevant difference between oral dydrogesterone and vaginal progesterone for LPS with respect to rate of ongoing pregnancy (risk ratio (RR), 1.04 (95% CI, 0.92-1.18); I(2) , 0%; seven RCTs, 3134 women), clinical pregnancy (RR, 1.07 (95% CI, 0.93-1.23); I(2) , 34%; eight RCTs, 3809 women) or miscarriage (RR, 0.77 (95% CI, 0.53-1.10); I(2) , 0%; seven RCTs, 906 clinical pregnancies). Two of the three studies reporting on dissatisfaction of treatment identified lower levels of dissatisfaction among women using oral dydrogesterone than among women using vaginal progesterone (oral dydrogesterone vs vaginal progesterone capsules: 2/79 (2.5%) vs 90/351 (25.6%), respectively; oral dydrogesterone vs vaginal progesterone gel: 19/411 (4.6%) vs 74/411 (18.0%), respectively). The third study showed no difference in dissatisfaction rate (oral dydrogesterone vs vaginal progesterone capsules: 8/96 (8.3%) vs 8/114 (7.0%), respectively). CONCLUSIONS: Oral dydrogesterone seems to be as effective as vaginal progesterone for LPS in ART cycles, and appears to be better tolerated . Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

True Reproducibility of UltraSound Techniques (TRUST): systematic review of reliability studies in obstetrics and gynecology.

OBJECTIVES: To examine the quality of methods used and the accuracy of the interpretation of agreement in existing studies that examine the reliability of ultrasound measurements and judgments in obstetrics and gynecology. METHODS: A systematic search of MEDLINE was performed on 25 March 2014, looking for studies that examined the reliability of ultrasound measurements and judgments in obstetrics and gynecology with evaluation of concordance (CCC) or intraclass (ICC) correlation coefficients or kappa as a main objective. RESULTS: Seven hundred and thirty-three records were examined on the basis of their title and abstract, of which 141 full-text articles were examined completely for eligibility. We excluded 29 studies because they did not report CCC/ICC/kappa, leaving 112 studies that were included in our analysis. Two studies reported both ICC and kappa and were counted twice, therefore, the number used as the denominator in the analyses was 114. Only 16/114 (14.0%) studies were considered to be well designed (independent acquisition and blinded analysis) and to have interpreted the results properly. Most errors occurring in the studies are likely to overestimate the reliability of the method examined. CONCLUSIONS: The vast majority of published studies examined had important flaws in design, interpretation and/or reporting. Such limitations are important to identify as they might create false confidence in the existing measurements and judgments, jeopardizing clinical practice and future research. Specific guidelines aimed at improving the quality of reproducibility studies that examine ultrasound methods should be encouraged.

Ovarian hyperstimulation syndrome: pathophysiology, staging, prediction and prevention.

OBJECTIVE: To identify, appraise and summarize the current evidence regarding the pathophysiology, staging, prediction and prevention of ovarian hyperstimulation syndrome (OHSS). METHODS: Two comprehensive systematic reviews were carried out: one examined methods of predicting either high ovarian response or OHSS and the other examined interventions aimed at reducing the occurrence of OHSS. Additionally, we describe the related pathophysiology and staging criteria. RESULTS: Seven studies examining methods of predicting OHSS and eight more examining methods of predicting high ovarian response to controlled ovarian stimulation were included. Current evidence shows that the best methods of predicting high response are antral follicle count and anti-Müllerian hormone levels, and that a high ovarian response (examined by the number of large follicles, estradiol concentration or the number of retrieved oocytes) is the best method of predicting the occurrence of OHSS. Ninety-seven randomized controlled trials examining the effect of several interventions for reducing the occurrence of OHSS were included. There was high-quality evidence that replacing human chorionic gonadotropin by gonadotropin-releasing hormone agonists or recombinant luteinizing hormone, and moderate-quality evidence that antagonist protocols, dopamine agonists and mild stimulation, reduce the occurrence of OHSS. The evidence for the effect of the other interventions was of low/very low quality. Additionally, we identified and described 12 different staging criteria. CONCLUSIONS: There are useful predictive tools and several preventive interventions aimed at reducing the occurrence of OHSS. Acknowledging and understanding them are of crucial importance for planning the treatment of, and, ultimately, eliminating, OHSS while maintaining high pregnancy rates.

Ultrasound guidance during embryo transfer: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: To summarize the current evidence on the effect of using ultrasound (US) guidance during embryo transfer (ET). METHODS: In this systematic review, we included randomized controlled trials examining the effect of the use of US guidance during ET; data from studies using the same catheter type in study arms were not pooled with the results from studies that used different catheter types. RESULTS: Twenty-one studies were included in the quantitative analysis: 18 compared 'US guidance' with 'clinical touch', of which one was subsequently excluded from the quantitative meta-analysis owing to a lack of available data, three studies compared transvaginal US guidance with transabdominal US guidance, and one study compared 'hysterosonometry before ET' with US guidance. Comparison of the use of US guidance with clinical touch, in studies that used the same catheter type in the study arms, indicated a benefit of using US guidance during ET on the rates of live birth (relative risk (RR), 1.48 (95% CI, 1.16-1.87)), based on two studies involving 888 women with moderate-quality evidence, and on the rates of clinical pregnancy (RR, 1.32 (95% CI, 1.18-1.46)), based on 13 studies involving 3641 women with high-quality evidence. However, when comparing the use of US guidance with clinical touch in studies that used different catheter types, the results suggest that using US guidance during ET has no effect on the rates of reproductive outcome: live birth (RR, 0.99 (95% CI, 0.83-1.19)), based on one study involving 1649 women with moderate-quality evidence; clinical pregnancy (RR, 1.04 (95% CI, 0.89-1.21)), based on five studies involving 2949 women with moderate-quality evidence. The estimates for the rate of miscarriage and for the other identified comparisons were imprecise. CONCLUSIONS: The available evidence suggests that there is a benefit of using US guidance during ET. However, both US-guided transfer and clinical touch should be considered acceptable, as the benefit of US is not large and should be balanced against the increased cost and need to change the catheter type. More studies are required before conclusions can be drawn regarding the effect of other techniques on reproductive outcome.

Assessment of ovarian reserve by antral follicle count in ovaries with endometrioma.

OBJECTIVE: To evaluate whether the antral follicle count (AFC) is underestimated in the presence of an endometrioma. METHODS: This was a retrospective cohort study assessing all women undergoing in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) at our clinic between January 2011 and December 2012 who had both ovaries and unilateral endometrioma. The primary outcome of the study was the difference between AFC and the number of oocytes retrieved per ovary. RESULTS: Within the study period 787 women underwent IVF/ICSI at our clinic. Sixty of these women had at least one endometrioma, but 23 were excluded from the analysis as six had only one ovary and 17 had bilateral endometriomas. Therefore a total of 37 women were included in this study and analysis. Compared with the contralateral ovaries, ovaries with an endometrioma were significantly larger in volume (median, 10.3 (interquartile range (IQR), 4.7-18.9) cm(3) vs median, 3.6 (IQR, 2.7-6.5) cm(3); P < 0.001) and presented a significantly lower AFC (median, 3.0 (IQR, 1.0-6.0) vs median, 5.0 (IQR, 2.0-6.5); P = 0.001). However, the median number of oocytes retrieved was similar (P = 0.60) between ovaries with an endometrioma (2.0 (IQR, 0.5-5.0)) and the contralateral ovaries (2.0 (IQR, 0.0-4.0)). Accordingly, the median difference between AFC and number of oocytes retrieved was significantly smaller (P = 0.005) for ovaries with an endometrioma (0.0 (IQR, -1.0 to 1.5) than for those without (2.0 (IQR, 0.0-4.0)). CONCLUSIONS: Although the AFC is reduced in ovaries with an endometrioma, the number of oocytes retrieved is similar, suggesting that the AFC is underestimated in such ovaries. We believe that this is a consequence of an impaired ability to detect small follicles in the presence of an endometrioma.

Ovarian response is a better predictor of clinical pregnancy rate following embryo transfer than is thin endometrium or presence of an endometrioma.

OBJECTIVES: To examine whether endometrial thickness and the presence of endometrioma are independent predictors of clinical pregnancy rate or simply associated with poor ovarian response (POR). METHODS: This was a retrospective cohort study assessing the first cycle of all women undergoing in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) in a university hospital in Brazil between January 2011 and December 2012. Only the first cycle of each woman within the study period was considered. Women over 40 years of age and those who used clomiphene citrate during controlled ovarian stimulation (COS) or did not undergo embryo transfer were excluded from analysis. POR was defined as ≤ three oocytes retrieved and a thin endometrium was defined as endometrial thickness ≤ 7.0 mm on the day of human chorionic gonadotropin (hCG) administration. We performed a multiple regression analysis to identify which of the following parameters were independent predictors of clinical pregnancy: age, number of oocytes retrieved, endometrial thickness or the presence of endometrioma. RESULTS: Within the study period, 787 women began COS, but 270 were excluded from analysis. Among the 517 women analyzed, those who achieved pregnancy were younger and yielded more oocytes. The proportion of POR was higher in women with a thin endometrium (17/57 (29.8%) vs 80/460 (17.4%); P = 0.03) and in women with endometrioma (15/39 (38.5%) vs 82/478 (17.2%); P = 0.002). The results of regression analysis showed that only age and the number of oocytes retrieved were independent predictors of pregnancy. Additionally, we observed higher clinical pregnancy rates in women with a thin endometrium from whom ≥ seven oocytes were retrieved (11/25 (44.0%)) compared to women with normal endometrial thickness (99/241 (41.1%)). Considering only women from whom ≥ four oocytes were retrieved, we observed reasonable pregnancy rates in those with a thin endometrium (14/40 (35.0%)) and in those with endometrioma (9/24 (37.5%)). CONCLUSION: Both a thin endometrium and the presence of endometrioma are associated with POR but are not important independent predictors of clinical pregnancy. Good pregnancy rates can be observed when these conditions are present in women with a good ovarian response.

Impact of endometriosis and its staging on assisted reproduction outcome: systematic review and meta-analysis.

OBJECTIVE: To evaluate whether the presence or severity of endometriosis affects the outcome of assisted reproductive techniques (ART). METHODS: In this systematic review, all studies comparing the outcome of ART in women with and those without endometriosis, or at different stages of the disease, were considered eligible. We used either risk ratio (RR) or mean difference (MD) and their 95%CIs for comparisons. The primary outcome was live birth; the secondary outcome was clinical pregnancy. Miscarriage and the number of oocytes retrieved were examined as additional outcomes. RESULTS: We included 92 studies in the review and 78 in the meta-analysis: 20,167 women with endometriosis were compared with 121,931 women without endometriosis, and 1703 women with Stage-III/IV endometriosis were compared with 2227 women with Stage-I/II endometriosis. The following results were observed for the comparison of women with endometriosis vs women without endometriosis: live birth, RR = 0.99 (95%CI, 0.92-1.06); clinical pregnancy, RR = 0.95 (95%CI, 0.89-1.02); miscarriage, RR = 1.31 (95%CI, 1.07-1.59); number of oocytes retrieved, MD = -1.56 (95%CI, -2.05 to -1.08). The following results were observed for the comparison of women with Stage-III/IV vs Stage-I/II endometriosis: live birth, RR = 0.94 (95%CI, 0.80-1.11); clinical pregnancy, RR = 0.90 (95%CI, 0.82-1.00); miscarriage, RR = 0.99 (95%CI, 0.73-1.36); number of oocytes retrieved, MD = -1.03 (95%CI, -1.67 to -0.39). CONCLUSIONS: Women with endometriosis undergoing ART have practically the same chance of achieving clinical pregnancy and live birth as do women with other causes of infertility. No relevant difference was observed in the chance of achieving clinical pregnancy and live birth following ART when comparing Stage-III/IV with Stage-I/II endometriosis. The quality of the evidence for the additional examined outcomes was very low, not allowing meaningful conclusions to be drawn.

Ultrasound for monitoring controlled ovarian stimulation: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To evaluate the efficacy and safety of monitoring controlled ovarian stimulation (COS) using ultrasonography. METHODS: We performed a search in April 2013 for randomized controlled trials (RCTs). Studies that compared different methods for monitoring COS, including ultrasound assessment of follicles (alone or combined with hormonal assessment), in at least one group were considered eligible. RESULTS: The search retrieved 1515 records, six of which were eligible. Five studies were included that compared ultrasonography alone with ultrasonography and hormonal assessment (estradiol and/or progesterone) and one study compared 2D and 3D ultrasound monitoring. None of the included studies reported on live birth. Four of the five studies reported on clinical pregnancy (RR, 0.95; 95% CI, 0.78­1.16; n = 611); the confidence interval (CI) was somewhat wide, but allowed us to conclude that ultrasonography alone differs little from ultrasonography combined with hormonal assessment. Three studies reported on the number of oocytes retrieved (mean difference (MD), 0.8 oocytes; 95% CI, ­0.4 to 2.0; n = 474); the CI was somewhat wide and did not permit us to conclude whether ultrasonography alone is better than or similar to ultrasonography and hormonal assessment for this outcome. All five studies reported on ovarian hyperstimulation syndrome (OR, 1.02; 95% CI, 0.47­2.25; n = 725) and only one study reported on miscarriage (RR, 0.37; 95% CI, 0.07­1.79; n = 45); for these two outcomes, the CI was very wide and did not permit us to conclude whether ultrasonography alone is better, similar or less effective than ultrasonography combined with hormonal assessment. For the study comparing 2D and 3D ultrasound, the reported outcomes were clinical pregnancy (RR, 1.00; 95% CI, 0.58­1.73, n = 72) and the number of oocytes retrieved (MD, ­0.4 oocytes; 95% CI, ­3.6 to 2.9; n = 72); for both, the CI was very wide and did not permit us to conclude whether use of 3D ultrasound is better, similar or less effective than use of 2D ultrasound. CONCLUSIONS: Current evidence suggests that monitoring COS only with ultrasonography is unlikely to substantially alter the chances of achieving a clinical pregnancy and the number of oocytes retrieved is similar to that when monitoring with ultrasonography and hormonal assessment. For the other outcomes and comparisons, the available data are inconclusive. We believe that more studies evaluating the optimal procedure for monitoring COS are needed.

Time-lapse embryo imaging for improving reproductive outcomes: systematic review and meta-analysis.

OBJECTIVE: To identify, appraise and summarize the available evidence regarding the effectiveness and safety of time-lapse embryo monitoring on the main outcomes of assisted reproductive techniques. METHODS: In this systematic review and meta-analysis, we included only randomized controlled trials (RCTs) comparing time-lapse embryo imaging with standard embryo monitoring. Our primary outcomes were live births (efficacy) and congenital abnormalities (safety). The secondary outcomes were clinical pregnancy, ongoing pregnancy and miscarriage. RESULTS: Two RCTs were considered eligible, and their data were extracted and included in a meta-analysis. In both studies embryos were transferred at the blastocyst stage. No studies reported rates of live birth or congenital abnormalities. Our estimates were not sufficiently precise to identify whether time-lapse monitoring provided a small benefit, no effect or minor harm on rates of clinical pregnancy (relative risk (RR), 1.05 (95% CI, 0.80-1.38)) or ongoing pregnancy (RR, 1.05 (95% CI, 0.76-1.45)), based on two studies involving 138 women with moderate-quality evidence. Considering the available data, we were unable to determine whether the intervention poses substantial benefit, no effect or substantial harm in the risk of miscarriage (RR, 0.95 (95% CI, 0.30-2.99)), based on two studies involving 76 clinical pregnancies with low-quality evidence. CONCLUSIONS: Time-lapse embryo imaging is unlikely to have a large effect on the chance of achieving clinical and/or ongoing pregnancy when transferring embryos at the blastocyst stage. More studies are required to improve the quality of the current evidence and also to examine whether this intervention is useful when transferring embryos at the cleavage stage.

Endometrial scratching performed in the non-transfer cycle and outcome of assisted reproduction: a randomized controlled trial.

OBJECTIVES: To investigate the effect of endometrial scratching, performed during oral contraceptive pill (OCP) pretreatment, on reproductive outcome and on ultrasound markers of endometrial receptivity, and to assess the pain involved in the procedure, in unselected women undergoing assisted reproductive techniques (ART). METHODS: Women undergoing ART were randomly allocated to undergo either endometrial scratching with a pipelle de Cornier or a sham procedure, 7-14 days before starting controlled ovarian stimulation (COS). We evaluated subsequent rates of clinical pregnancy, live birth, implantation, miscarriage and multiple pregnancy. Pain during the procedure was evaluated using a 10-cm visual analog scale. Endometrial thickness and volume and three-dimensional power Doppler (3D-PD) indices (vascularization index (VI), flow index (FI) and vascularization flow index (VFI)) were assessed during COS when there was at least one follicle ≥ 17 mm in diameter. RESULTS: We included 158 women. Endometrial scratching was associated with higher rates of live birth (41.8% vs 22.8%, P = 0.01) and clinical pregnancy (49.4% vs 29.1%, P = 0.01) and higher pain score (6.42 ± 2.35 cm vs 1.82 ± 1.52 cm, P < 0.001), endometrial VI (3.71 ± 1.77 vs 2.95 ± 1.56, P < 0.01) and VFI (0.97 ± 0.51 vs 0.76 ± 0.40, P < 0.01). There was no significant effect of endometrial scratching on rate of miscarriage (15.4% vs 21.7%, P = 0.53) or multiple pregnancy (22.5% vs 25.0%, P = 0.79), or on endometrial thickness (10.12 ± 1.55 mm vs 9.98 ± 1.62 mm, P = 0.59), endometrial volume (6.18 ± 1.63 cm(3) vs 6.01 ± 1.48 cm(3) , P = 0.51) or FI (26.12 ± 2.82 vs 25.91 ± 2.72, P = 0.65). CONCLUSIONS: Endometrial scratching performed once, during OCP pretreatment 7-14 days before starting COS, increases the chance of live birth and clinical pregnancy, but might cause considerable pain.

Clomiphene combined with gonadotropins and GnRH antagonist versus conventional controlled ovarian hyperstimulation without clomiphene in women undergoing assisted reproductive techniques: systematic review and meta-analysis.

PURPOSE: To compare the effectiveness and safety of controlled ovarian hyperstimulation (COH) using clomiphene citrate associated with gonadotropin and GnRH antagonist (CC + Ant) versus conventional COH without clomiphene citrate (Non-CC) for women undergoing assisted reproductive techniques (ART). METHODS: Systematic review and meta-analysis of randomized controlled-trials comparing CC + Ant versus non-CC. The last search was performed in Apr 13 2012. The following outcomes were retrieved from included trials and compared between CC + Ant versus non-CC: live birth, clinical pregnancy, ovarian hyperstimulation syndrome (OHSS), miscarriage, multiple pregnancy, endometrial thickness, total oocytes retrieved, MII oocytes retrieved, total gonadotropin used, and duration of COH. RESULTS: Seven trials (702 participants) were included. There was no significant difference in live birth (55/182 = 30.2 % vs. 47/181 = 26.0 %, p = 0.26, CC + Ant vs. non-CC, respectively), clinical pregnancy (98/346 = 28.3 % vs. 84/356 = 23.6 %, p = 0.12), miscarriage (6/35 = 17.1 % vs. 7/32 = 21.9 %, p = 0.42), endometrial thickness, and on the number of oocytes retrieved. There was a significant reduction in OHSS (1/216 = 0.5 % vs. 9/217 = 4.1 %, p = 0.01), consumption of gonadotropins, and duration of COH. CONCLUSIONS: Compared to non-CC, CC + Ant is likely to reduce the risk of OHSS, medication costs, and the duration of COH without evidence of effect on live birth and clinical pregnancy. More trials are still needed to improve the quality of the evidence. Future studies should evaluate women with PCOS or at increased risk of OHSS, quality of life, satisfaction with the treatment, total cost per live birth, and frequency of congenital anomalies.