Accuracy of Antenatal Ultrasound in Predicting Large for Gestational Age Babies: Population Based Cohort Study.

BACKGROUND: Pregnancies with large for gestational age fetuses are at increased risk of adverse maternal and neonatal outcomes. There is uncertainty about how to manage birth in such pregnancies. Current guidelines recommend a discussion with women of the pros and cons of options including expectant management, induction of labour and caesarean birth. For women to be able to make an informed decision about birth, antenatal detection of large for gestational age is essential. OBJECTIVE: To investigate the ability of antenatal ultrasound scans to predict large for gestational age at birth. STUDY DESIGN: In this retrospective cohort study, we analysed data from a routinely collected database from the West Midlands, United Kingdom. We included pregnancies that had an antenatal ultrasound estimated fetal weight between 35+0 and 38+0 weeks gestation for any indication, as well as a subgroup where the reason for scan was that the fetus was suspected to be big. Large for gestational age was defined as >90th customized GROW centile, for estimated fetal weight as well as for neonatal weight. We also tested performance of an uncustomized standard, with Hadlock fetal weight >90th centile and neonatal weight >4kg. We calculated diagnostic characteristics for the whole population as well as groups with different maternal body mass indices. RESULTS: The study cohort consisted of 26,527 pregnancies which on average had a scan at 256 days gestation and delivered 20 days later at a median of 276 days (interquartile range 15). In total 2241 (8.4%) of neonates were large for gestational age by customized centiles, of which 1459 (65.1%) had a scan estimated fetal weight >90th centile, with a false positive rate of 8.6% and a positive predictive value of 41.0%. In the subgroup of 912 (3.4%) pregnancies scanned for a suspected large fetus, 293 (32.1%) babies were large for gestational age at birth, giving a positive predictive value of 50.3%, with sensitivity of 77.1% and false positive rate 36.0%. When comparing subgroups from low (<18.5kg/m2) to high body mass index (>30kg/m2), sensitivity increased from 55.6 to 67.8%, false positive rate from 5.2 to 11.5% and positive predictive value from 32.1 to 42.3%. A total of 2585 (9.7%) babies were macrosomic (birthweight >4kg), and of these 1058 (40.9%) were large for gestational age (>90th centile) antenatally by Hadlock's growth standard, with a false positive rate of 4.9% and a positive predictive value 41.0%. Analysis within subgroups showed better performance by customized compared to uncustomized standards for low body mass index (<18.5; diagnostic odds ratio 23.0 vs 6.4) and high body mass index (>30; diagnostic odds ration 16.2 vs 8.8). CONCLUSION: Late third trimester ultrasound estimation of fetal weight for any indication has good ability to identify and predict large for gestational age at birth, and improves with the use of a customised standard. Detection rate is better when ultrasound is performed for a suspected large fetus, however at the risk of higher false positive diagnosis. Our results provide information for women and clinicians to aid antenatal decision making about birth of a fetus suspected of being large for gestational age.

Lessons learned from bovine subclinical endometritis: A systematic review exploring its potential relevance to chronic endometritis in women.

Chronic endometritis (CE) in humans is asymptomatic inflammation of the endometrium, associated with poor reproductive outcomes. Similarly asymptomatic endometrial inflammation in cows, termed subclinical endometritis (SCE), is associated with adverse reproductive outcomes. While the pathophysiology and treatment options for CE in humans remains poorly defined, the financial implications of SCE in dairy cows mean it has been intensively researched. We performed a systematic review with an emergent theme thematic analysis of studies of SCE in cows, to determine potential areas of interest in human CE research. A literature search for studies of subclinical endometritis in cows published between 1990 and November 2021 was performed across Embase, Medline, Scopus and CINAHL. Studies of symptomatic or clinical endometritis were excluded. Thematic analysis across two broad themes were explored: diagnostic methods and pathophysiology of SCE. In total, 44 bovine studies were included. 12 studies reported on diagnostic methodology. The primary emergent theme was the use of cytology for the diagnosis of SCE. This method has a lower sensitivity than histopathology but is less invasive and more specific than alternative techniques of ultrasound, vaginoscopy, or metabolic markers. The subthemes related to pathophysiology were identified as type of endometritis, metabolic stress, artificial insemination, infective causes, and altered cellular pathways. Despite the lack of symptoms, cellular pathways of inflammation including NFkB, MAPK, and inflammasomes were found to be activated. The key themes related to the diagnosis and pathophysiology of SCE in cows identified in this systematic review highlight potential areas for future research into human CE.

Multivariable prediction models for fetal macrosomia and large for gestational age: A systematic review.

BACKGROUND: The identification of large for gestational age (LGA) and macrosomic fetuses is essential for counselling and managing these pregnancies. OBJECTIVES: To systematically review the literature for multivariable prediction models for LGA and macrosomia, assessing the performance, quality and applicability of the included model in clinical practice. SEARCH STRATEGY: MEDLINE, EMBASE and Cochrane Library were searched until June 2022. SELECTION CRITERIA: We included observational and experimental studies reporting the development and/or validation of any multivariable prediction model for fetal macrosomia and/or LGA. We excluded studies that used a single variable or did not evaluate model performance. DATA COLLECTION AND ANALYSIS: Data were extracted using the Checklist for critical appraisal and data extraction for systematic reviews of prediction modelling studies checklist. The model performance measures discrimination, calibration and validation were extracted. The quality and completion of reporting within each study was assessed by its adherence to the TRIPOD (Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis) checklist. The risk of bias and applicability were measured using PROBAST (Prediction model Risk Of Bias Assessment Tool). MAIN RESULTS: A total of 8442 citations were identified, with 58 included in the analysis: 32/58 (55.2%) developed, 21/58 (36.2%) developed and internally validated and 2/58 (3.4%) developed and externally validated a model. Only three studies externally validated pre-existing models. Macrosomia and LGA were differentially defined by many studies. In total, 111 multivariable prediction models were developed using 112 different variables. Model discrimination was wide ranging area under the receiver operating characteristics curve (AUROC 0.56-0.96) and few studies reported calibration (11/58, 19.0%). Only 5/58 (8.6%) studies had a low risk of bias. CONCLUSIONS: There are currently no multivariable prediction models for macrosomia/LGA that are ready for clinical implementation.

Fetal loss and long-term maternal morbidity and mortality: A systematic review and meta-analysis.

BACKGROUND: Evidence suggests common pathways between pregnancy losses and subsequent long-term maternal morbidity, rendering pregnancy complications an early chronic disease marker. There is a plethora of studies exploring associations between miscarriage and stillbirth with long-term adverse maternal health; however, these data are inconclusive. METHODS AND FINDINGS: We systematically searched MEDLINE, EMBASE, AMED, BNI, CINAHL, and the Cochrane Library with relevant keywords and MeSH terms from inception to June 2023 (no language restrictions). We included studies exploring associations between stillbirth or miscarriage and incidence of cardiovascular, malignancy, mental health, other morbidities, and all-cause mortality in women without previous pregnancy loss. Studies reporting short-term morbidity (within a year of loss), case reports, letters, and animal studies were excluded. Study selection and data extraction were performed by 2 independent reviewers. Risk of bias was assessed using the Newcastle Ottawa Scale (NOS) and publication bias with funnel plots. Subgroup analysis explored the effect of recurrent losses on adverse outcomes. Statistical analysis was performed using an inverse variance random effects model and results are reported as risk ratios (RRs) with 95% confidence intervals (CIs) and prediction intervals (PIs) by combining the most adjusted RR, odds ratios (ORs) and hazard ratios (HRs) under the rare outcome assumption. We included 56 observational studies, including 45 in meta-analysis. There were 1,119,815 women who experienced pregnancy loss of whom 951,258 had a miscarriage and 168,557 stillbirth, compared with 11,965,574 women without previous loss. Women with a history of stillbirth had a greater risk of ischaemic heart disease (IHD) RR 1.56, 95% CI [1.30, 1.88]; p < 0.001, 95% PI [0.49 to 5.15]), cerebrovascular (RR 1.71, 95% CI [1.44, 2.03], p < 0.001, 95% PI [1.92, 2.42]), and any circulatory/cardiovascular disease (RR 1.86, 95% CI [1.01, 3.45], p = 0.05, 95% PI [0.74, 4.10]) compared with women without pregnancy loss. There was no evidence of increased risk of cardiovascular disease (IHD: RR 1.11, 95% CI [0.98, 1.27], 95% PI [0.46, 2.76] or cerebrovascular: RR 1.01, 95% CI [0.85, 1.21]) in women experiencing a miscarriage. Only women with a previous stillbirth were more likely to develop type 2 diabetes mellitus (T2DM) (RR: 1.16, 95% CI [1.07 to 2.26]; p < 0.001, 95% PI [1.05, 1.35]). Women with a stillbirth history had an increased risk of developing renal morbidities (RR 1.97, 95% CI [1.51, 2.57], p < 0.001, 95% [1.06, 4.72]) compared with controls. Women with a history of stillbirth had lower risk of breast cancer (RR: 0.80, 95% CI [0.67, 0.96], p-0.02, 95% PI [0.72, 0.93]). There was no evidence of altered risk of other malignancies in women experiencing pregnancy loss compared to controls. There was no evidence of long-term mental illness risk in women with previous pregnancy losses (stillbirth: RR 1.90, 95% CI [0.93, 3.88], 95% PI [0.34, 9.51], miscarriage: RR 1.78, 95% CI [0.88, 3.63], 95% PI [1.13, 4.16]). The main limitations include the potential for confounding due to use of aggregated data with variable degrees of adjustment. CONCLUSIONS: Our results suggest that women with a history of stillbirth have a greater risk of future cardiovascular disease, T2DM, and renal morbidities. Women experiencing miscarriages, single or multiple, do not seem to have an altered risk.

The endometrial microbiota and early pregnancy loss.

The human endometrium is a dynamic entity that plays a pivotal role in mediating the complex interplay between the mother and developing embryo. Endometrial disruption can lead to pregnancy loss, impacting both maternal physical and psychological health. Recent research suggests that the endometrial microbiota may play a role in this, although the exact mechanisms are still being explored, aided by recent technological advancements and our growing understanding of host immune responses. Suboptimal or dysbiotic vaginal microbiota, characterized by increased microbial diversity and reduced Lactobacillus dominance, has been associated with various adverse reproductive events, including miscarriage. However, the mechanisms linking the lower reproductive tract microbiota with pregnancy loss remain unclear. Recent observational studies implicate a potential microbial continuum between the vaginal and endometrial niche in patients with pregnancy loss; however, transcervical sampling of the low biomass endometrium is highly prone to cross-contamination, which is often not controlled for. In this review, we explore emerging evidence supporting the theory that a dysbiotic endometrial microbiota may modulate key inflammatory pathways required for successful embryo implantation and pregnancy development. We also highlight that a greater understanding of the endometrial microbiota, its relationship with the local endometrial microenvironment, and potential interventions remain a focus for future research.

Routine use of cell salvage during cesarean section: A practice evaluation.

INTRODUCTION: Intraoperative cell salvage is a well-documented alternative to donor blood transfusion given the scarcity of donor blood pools and the incumbent risk of allogenic blood transfusion. Its use in obstetrics has been limited by concern over fetal alloimmunization due to the risk of fetomaternal hemorrhage. However, there are a paucity of studies reporting on outcome. The aim of this study was to report on a four-year experience of routine use of intraoperative cell salvage and the impact on subsequent pregnancy outcomes. MATERIAL AND METHODS: This was a tertiary center retrospective service evaluation cohort study and included all women undergoing cesarean section between December 2014 and November 2018 in a tertiary obstetric unit, identifying women who had reinfusion of intraoperative cell salvage. Data regarding index pregnancy as well as subsequent pregnancies at the hospital were extracted from hospital electronic records. Subsequent pregnancy outcome and maternal antibody status in that pregnancy were collected up until November 2022. RESULTS: During the study period, 6656 cesarean sections were performed, with 436 (6.6%) receiving reinfusion of salvaged blood. The mean volume of reinfused blood was 396 mL. A total of 49 (0.7%) women received donor blood transfusion. Of those who received reinfusion of salvaged blood, 79 (18.1%) women had subsequent pregnancies over the eight-year follow-up period. There was one case (0.23%) of fetal cell alloimmunization demonstrated by the presence of anti-D antibodies on the subsequent pregnancy booking bloods. CONCLUSIONS: Routine intraoperative cell salvage may be used to reduce the need for blood transfusion during cesarean section. The risk of fetal cell alloimmunization in a future pregnancy following reinfusion of intraoperative cell salvage is one in 436. Given an apparent small risk of fetal cell alloimmunization, further work is required to establish the safety profile of intraoperative cell salvage in pregnancy.

Preconceptual administration of doxycycline in women with recurrent miscarriage and chronic endometritis: protocol for the Chronic Endometritis and Recurrent Miscarriage (CERM) trial, a multicentre, double-blind, placebo-controlled, adaptive randomised trial with an embedded translational substudy.

INTRODUCTION: Recurrent miscarriage is a common condition with a substantial associated morbidity. A hypothesised cause of recurrent miscarriage is chronic endometritis (CE). The aetiology of CE remains uncertain. An association between CE and recurrent miscarriage has been shown. This study will aim to determine if preconceptual administration of doxycycline, in women with recurrent miscarriages, and CE, reduces first trimester miscarriages, increasing live births. METHODS AND ANALYSIS: Chronic Endometritis and Recurrent Miscarriage is a multicentre, double-blind adaptive trial with an embedded translational substudy. Women with a history of two or more consecutive first trimester losses with evidence of CE on endometrial biopsy (defined as ≥5 CD138 positive cells per 10 mm2) will be randomised to oral doxycycline or placebo for 14 days. A subset will be recruited to a mechanistic substudy in which microbial swabs and preintervention/postintervention endometrial samples will be collected. Up to 3062 women recruited from 29 National Health Service (NHS) hospital sites across the UK are expected to be screened with up to 1500 women randomised in a 1:1 ratio. Women with a negative endometrial biopsy (defined as <5 CD138 positive cells per 10 mm2) will also be followed up to test validity of the tool. The primary outcome is live births plus pregnancies ≥24 + 0 weeks gestation at the end of the trial, in the first or subsequent pregnancy. Secondary clinical outcomes will also be assessed. Exploratory outcomes will assess the effect of doxycycline treatment on the endometrial microbiota, the differentiation capacity of the endometrium and the senescent profile of the endometrium with CE. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the NHS Research Ethics Committee Northwest-Haydock (19/NW/0462). Written informed consent will be gained from all participants. The results will be published in an open-access peer-reviewed journal and reported in the National Institute for Health and Care Research journals library. TRIAL REGISTRATION NUMBER: ISRCTN23947730.

Lived experience of recurrent miscarriage: women and their partners' experience of subsequent pregnancy and support within an NHS specialist clinic - a qualitative study.

OBJECTIVE: This study aims to describe the lived experiences of couples with a history of recurrent miscarriage in subsequent pregnancies and their perception of clinic support and cytogenetic investigations. DESIGN: A qualitative interview study with a phenomenological approach. Semistructured interviews were conducted using video conferencing software. Two researchers coded the transcripts and developed themes. SETTING: A National Health Service (NHS) hospital in central England between May 2021 and July 2021, during the COVID-19 pandemic. PARTICIPANTS: Patients attending a specialist recurrent miscarriage clinic and their partners. This clinic accepts referrals from all over the UK for couples who have suffered two or more miscarriages. RESULTS: Seventeen participants were interviewed: 14 women and 3 male partners. Six main themes were identified from the data. Three related to the women's lived experience of recurrent miscarriage (emotions in pregnancy, confidence in their bodies, expectations and coping strategies) and three related to the clinical support offered by the NHS service (impact of early pregnancy scanning, effect of the COVID-19 pandemic and cytogenetic investigations). CONCLUSIONS: Pregnancy following recurrent miscarriage is extremely difficult. Recurrent miscarriage specialist services can provide couples with support and access to early pregnancy scanning, which can make the first trimester of pregnancy manageable. Partners should not be excluded from the clinic as it can result in a feeling of disconnect. Cytogenetic testing of pregnancy tissue can offer couples with recurrent miscarriage closure after pregnancy loss and is a desired investigation.

The role of small extracellular vesicle-miRNAs in endometriosis.

Endometriosis is defined by the presence of extrauterine endometrial-like tissue, which can cause pain and infertility in 10% of reproductive-age women. To date, the pathogenesis is poorly understood resulting in significant diagnostic delays and poor therapeutic outcomes in many women. Small extracellular vesicles (sEVs) (<200 nm) are cell-derived vesicles containing molecules that can influence gene expression and behaviour in target cells. One such cargo are microRNAs (miRNAs), which are short, non-coding RNAs mostly 19-25 nucleotides in length that regulate post-transcriptional gene expression. This mini-review focuses on the role of sEV-miRNAs, which are conceivably better biomarkers for endometriosis than free miRNAs, which reflect the true pathophysiological state in the body, as sEV-encapsulated miRNAs are protected from degradation compared to free miRNA and provide direct cell-to-cell communication via sEV surface proteins. sEV-miRNAs have been implicated in the immunomodulation of macrophages, the proliferation, migration and invasion of endometrial cells, and angiogenesis, all hallmarks of endometriosis. The diagnostic potential of sEV-miRNA was investigated in one study that reported the sensitivity and specificity of two sEV-miRNAs (hsa-miR-22-3p and hsa-miR-320a-3p) in distinguishing endometriosis from non-endometriosis cases. Only three studies have explored the therapeutic potential of sEV-miRNAs in vivo in mice-two looked into the role of sEV-hsa-miR-214-3p in decreasing fibrosis, and one investigated sEV-hsa-miR-30c-5p in suppressing the invasive and migratory potential of endometriotic lesions. While early results are encouraging, studies need to further address the potential influence of factors such as the menstrual cycle as well as the location and extent of endometriotic lesions on miRNA expression in sEVs. Given these findings, and extrapolating from other conditions such as cancer, diabetes, and pre-eclampsia, sEV-miRNAs could present an attractive and urgently needed future diagnostic and therapeutic target for millions of women suffering from endometriosis. However, research in this area is hampered by lack of adherence to the International Society for Extracellular Vesicles 2018 guideline in separating and characterising sEVs, as well as the World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonisation Project protocols.

Fertility preservation, its effectiveness and its impact on disease status in pre-menopausal women with breast cancer: A systematic review and meta-analysis.

INTRODUCTION: Preservation of reproductive function is a key concern for many premenopausal women with breast cancer, given the known gonadotoxic effects of treatments. The present systematic review aimed to investigate the effectiveness and safety of fertility preservation strategies in pre-menopausal women with breast cancer. METHODS: Primary research assessing fertility preservation strategies of any type was identified. Markers of preservation of fertility including return of menstrual function, clinical pregnancy rates and live birth rates were selected as main outcome measures. An additional analysis of safety data was also performed. RESULTS: Fertility preservation interventions were overall associated with higher fertility outcomes: with a pooled odds ratio 4.14 (95% CI 3.59-4.77) for any kind of fertility preservation intervention. This was seen both for return of menstruation and for clinical pregnancy rate, but not for live birth rates. Fertility preservation was associated with a reduced rate of disease recurrence (OR 0.63 (95% CI 0.49-0.81)), while there was no significant difference in disease free survival (OR 0.88 (95% CI 0.74-1.05)) or in overall survival (OR 0.9 (95% CI 0.74-1.10)) between the fertility preservation group and those who had not undergone fertility preservation. CONCLUSION: Fertility preservation is both effective in preserving reproductive function, and safe with regard to disease recurrence, disease free survival and overall survival in premenopausal women with breast cancer.

Heparin for women with recurrent miscarriage and inherited thrombophilia (ALIFE2): an international open-label, randomised controlled trial.

BACKGROUND: Anticoagulant therapy might reduce the number of miscarriages and adverse pregnancy outcomes in women with recurrent pregnancy loss and inherited thrombophilia. We aimed to assess use of low-molecular-weight heparin (LMWH) versus standard care in this population. METHODS: The ALIFE2 trial was an international open-label, randomised controlled trial undertaken in hospitals in the UK (n=26), the Netherlands (n=10), the USA (n=2), Belgium (n=1), and Slovenia (n=1). Women aged 18-42 years who had two or more pregnancy losses and confirmed inherited thrombophilia, and who were trying to conceive or were already pregnant (≤7 weeks' gestation), were eligible for inclusion. Women were randomly assigned (1:1) to use low-dose LMWH or not (alongside standard care in both groups) once they had a positive urine pregnancy test. LMWH was started at or before 7 weeks' gestation and continued until the end of pregnancy. The primary outcome measure was livebirth rate, assessed in all women with available data. Safety outcomes included bleeding episodes, thrombocytopenia, and skin reactions, and were assessed in all randomly assigned women who reported a safety event. The trial was registered within the Dutch Trial Register (NTR3361) and EudraCT (UK: 2015-002357-35). FINDINGS: Between Aug 1, 2012, and Jan 30, 2021, 10 625 women were assessed for eligibility, 428 were registered, and 326 conceived and were randomly assigned (164 to LMWH and 162 to standard care). 116 (72%) of 162 women with primary outcome data in the LMWH group and 112 (71%) of 158 in the standard care group had livebirths (adjusted odds ratio 1·08, 95% CI 0·65 to 1·78; absolute risk difference, 0·7%, 95% CI -9·2% to 10·6%). 39 (24%) of 164 women in the LMWH group and 37 (23%) of 162 women in the standard care group reported adverse events. INTERPRETATION: LMWH did not result in higher livebirth rates in women who had two or more pregnancy losses and confirmed inherited thrombophilia. We do not advise use of LMWH in women with recurrent pregnancy loss and inherited thrombophilia, and we advise against screening for inherited thrombophilia in women with recurrent pregnancy loss. FUNDING: National Institute for Health and Care Research and the Netherlands Organization for Health Research and Development.

A core outcome set for trials in miscarriage management and prevention: An international consensus development study.

OBJECTIVE: To develop core outcome sets (COS) for miscarriage management and prevention. DESIGN: Modified Delphi survey combined with a consensus development meeting. SETTING: International. POPULATION: Stakeholder groups included healthcare providers, international experts, researchers, charities and couples with lived experience of miscarriage from 15 countries: 129 stakeholders for miscarriage management and 437 for miscarriage prevention. METHODS: Modified Delphi method and modified nominal group technique. RESULTS: The final COS for miscarriage management comprises six outcomes: efficacy of treatment, heavy vaginal bleeding, pelvic infection, maternal death, treatment or procedure-related complications, and patient satisfaction. The final COS for miscarriage prevention comprises 12 outcomes: pregnancy loss <24 weeks' gestation, live birth, gestation at birth, pre-term birth, congenital abnormalities, fetal growth restriction, maternal (antenatal) complications, compliance with intervention, patient satisfaction, maternal hospitalisation, neonatal or infant hospitalisation, and neonatal or infant death. Other outcomes identified as important were mental health-related outcomes, future fertility and health economic outcomes. CONCLUSIONS: This study has developed two core outcome sets, through robust methodology, that should be implemented across future randomised trials and systematic reviews in miscarriage management and prevention. This work will help to standardise outcome selection, collection and reporting, and improve the quality and safety of future studies in miscarriage.

ESHRE guideline: recurrent pregnancy loss: an update in 2022.

STUDY QUESTION: What are the updates for the recommended management of women with recurrent pregnancy loss (RPL) based on the best available evidence in the literature from 2017 to 2022? SUMMARY ANSWER: The guideline development group (GDG) updated 11 existing recommendations on investigations and treatments for RPL, and how care should be organized, and added one new recommendation on adenomyosis investigation in women with RPL. WHAT IS KNOWN ALREADY: A previous ESHRE guideline on RPL was published in 2017 and needs to be updated. STUDY DESIGN SIZE DURATION: The guideline was developed and updated according to the structured methodology for development and update of ESHRE guidelines. The literature searches were updated, and assessments of relevant new evidence were performed. Relevant papers published between 31 March 2017 and 28 February 2022 and written in English were included. Cumulative live birth rate, live birth rate, and pregnancy loss rate (or miscarriage rate) were considered the critical outcomes. PARTICIPANTS/MATERIALS SETTING METHODS: Based on the collected evidence, recommendations were updated and discussed until consensus was reached within the GDG. A stakeholder review was organized after the updated draft was finalized. The final version was approved by the GDG and the ESHRE Executive Committee. MAIN RESULTS AND THE ROLE OF CHANCE: The new version of the guideline provides 39 recommendations on risk factors, prevention, and investigation in couples with RPL, and 38 recommendations on treatments. These includes 62 evidence-based recommendations-of which 33 were formulated as strong recommendations and 29 as conditional-and 15 good practice points. Of the evidence-based recommendations, 12 (19.4%) were supported by moderate-quality evidence. The remaining recommendations were supported by low (34 recommendations; 54.8%), or very low-quality evidence (16 recommendations; 25.8%). Owing to the lack of evidence-based investigations and treatments in RPL care, the guideline also clearly mentions those investigations and treatments that should not be used for couples with RPL. LIMITATIONS REASONS FOR CAUTION: The guidelines have been updated; however, several investigations and treatments currently offered to couples with RPL have not been well studied; for most of these investigations and treatments, a recommendation against using the intervention or treatment was formulated based on insufficient evidence. Future studies may require these recommendations to be revised. WIDER IMPLICATIONS OF THE FINDINGS: The guideline provides clinicians with clear advice on best practice in RPL, based on the best and most recent evidence available. In addition, a list of research recommendations is provided to stimulate further studies in RPL. Still, the absence of a unified definition of RPL is one of the most critical consequences of the limited scientific evidence in the field. STUDY FUNDING/COMPETING INTERESTS: The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the dissemination of the guideline. The guideline group members did not receive payment.O.B.C. reports being a member of the executive board of the European Society for Reproductive Immunology and has received payment for honoraria for giving lectures about RPL in Australia in 2020. M.G. reports unconditional research and educational grant received by the Centre for Reproductive Medicine, Amsterdam UMC from Guerbet, Merck and Ferring, not related to the presented work. S.L. reports position funding from EXAMENLAB Ltd. and ownership interest by stock or partnership of EXAMENLAB Ltd (CEO). S.Q. reports being a deputy director of Tommy's National centre for miscarriage research, with payment received by the institution for research, staff time, and consumables for research. H.S.N. reports grants with payment to institution from Freya Biosciences ApS, Ferring Pharmaceuticals, BioInnovation Institute, the Danish ministry of Education, Novo Nordic Foundation, Augustinus Fonden, Oda og Hans Svenningsens Fond, Demant Fonden, Ole Kirks Fond, and Independent Research Fund Denmark and speakers' fees for lectures from Ferring Pharmaceuticals, Merck A/S, Astra Zeneca, IBSA Nordic and Cook Medical. She also reports to be an unpaid founder and chairman of a maternity foundation. M.-L.v.d.H. received small honoraria for lectures on RPL care. The other authors have no conflicts of interest to declare. DISCLAIMER: This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained.Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgment to each individual presentation, nor variations based on locality and facility type.ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose. (Full disclaimer available at www.eshre.eu/guidelines.).

The impact of maternal obesity on in vivo uterine contractile activity during parturition in the rat.

Maternal obesity is associated with increased risk of prolonged and dysfunctional labor and emergency caesarean section. To elucidate the mechanisms behind the associated uterine dystocia, a translational animal model is required. Our previous work identified that exposure to a high-fat, high-cholesterol (HFHC) diet to induce obesity down-regulates uterine contractile associated protein expression and causes asynchronous contractions ex vivo. This study aims to investigate the impact of maternal obesity on uterine contractile function in vivo using intrauterine telemetry surgery. Virgin female Wistar rats were fed either a control (CON, n = 6) or HFHC (n = 6) diet for 6 weeks prior to conception, and throughout pregnancy. On Day 9 of gestation, a pressure-sensitive catheter was surgically implanted aseptically within the gravid uterus. Following 5 days recovery, intrauterine pressure (IUP) was recorded continuously until delivery of the 5th pup (Day 22). HFHC induced obesity led to a significant 1.5-fold increase in IUP (p = 0.026) and fivefold increase in frequency of contractions (p = 0.013) relative to CON. Determination of the time of labor onset identified that HFHC rats IUP (p = 0.046) increased significantly 8 h prior to 5th pup delivery, which contrasts to CON with no significant increase. Myometrial contractile frequency in HFHC rats significantly increased 12 h prior to delivery of the 5th pup (p = 0.023) compared to only 3 h in CON, providing evidence that labor in HFHC rats was prolonged by 9 h. In conclusion, we have established a translational rat model that will allow us to unravel the mechanism behind uterine dystocia associated with maternal obesity.

Ethnic group and reason for assisted reproductive technology failure: analysis of the Human Fertilisation and Embryology Authority registry data from 2017 to 2018.

OBJECTIVE: To understand how the risk of different assisted reproductive technology (ART) failure types varies by ethnic group and explore the role of mediation by maternal age and suspected etiology. DESIGN: An observational study of 48,750 women who undertook treatment with ART in the United Kingdom between January 2017 and December 2018. SETTING: The Human Fertilisation and Embryology Authority national ART registry of the United Kingdom. PATIENT(S): Women who commenced a first cycle of ART for the purpose of primary fresh embryo transfer using their own oocytes were included. INTERVENTION(S): Maternal ethnic group. MAIN OUTCOME MEASURE(S): The ART failure types were modeled on the maternal ethnic group using the Poisson regression to produce relative risks (RRs) with 95% confidence intervals. The potential indirect effects of maternal age and etiology of subfertility were estimated, and the RRs with 95% confidence intervals were produced. RESULT(S): Black women were at greater risk of treatment failure with respect to live birth than women who were white: cycle cancellation, RR of 2.15 (1.78-2.62); failed fertilization, RR of 2.36 (1.90-2.93); unintended freeze-all, RR of 1.71 (1.43-2.05); failed implantation, RR of 1.23 (1.12-1.34); and pregnancy loss, RR of 1.38 (1.15-1.64). Women who were Asian were at moderately increased risk: RRs of 1.31 (1.17-1.47), 1.60 (1.42-1.80), 1.25 (1.14-1.38), 1.11 (1.07-1.16), and 1.13 (1.03-1.23), across the same outcomes, respectively. Inequality may have been reduced had women of all ethnicities initiated treatment at the same age. CONCLUSION(S): Black women were at greatest risk of all failure types, and women who were Asian were at intermediate risk compared with women who were white. Some of the risks among women who were black may be mediated by maternal age.

Induction of labour for predicted macrosomia: study protocol for the 'Big Baby' randomised controlled trial.

INTRODUCTION: Large-for-gestational age (LGA) fetuses have an increased risk of shoulder dystocia. This can lead to adverse neonatal outcomes and death. Early induction of labour in women with a fetus suspected to be macrosomic may mitigate the risk of shoulder dystocia. The Big Baby Trial aims to find if induction of labour at 38+0-38+4 weeks' gestation, in pregnancies with suspected LGA fetuses, reduces the incidence of shoulder dystocia. METHODS AND ANALYSIS: The Big Baby Trial is a multicentre, prospective, individually randomised controlled trial of induction of labour at 38+0 to 38+4 weeks' gestation vs standard care as per each hospital trust (median gestation of delivery 39+4) among women whose fetuses have an estimated fetal weight >90th customised centile according to ultrasound scan at 35+0 to 38+0 weeks' gestation. There is a parallel cohort study for women who decline randomisation because they opt for induction, expectant management or caesarean section. Up to 4000 women will be recruited and randomised to induction of labour or to standard care. The primary outcome is the incidence of shoulder dystocia; assessed by an independent expert group, blind to treatment allocation, from delivery records. Secondary outcomes include birth trauma, fractures, haemorrhage, caesarean section rate and length of inpatient stay. The main trial is ongoing, following an internal pilot study. A qualitative reporting, health economic evaluation and parallel process evaluation are included. ETHICS AND DISSEMINATION: The study received a favourable opinion from the South West-Cornwall and Plymouth Health Research Authority on 23/03/2018 (IRAS project ID 229163). Study results will be reported in the National Institute for Health Research journal library and published in an open access peer-reviewed journal. We will plan dissemination events for key stakeholders. TRIAL REGISTRATION NUMBER: ISRCTN18229892.

Predictive Models for Estimating the Probability of Successful Vaginal Birth After Cesarean Delivery: A Systematic Review.

OBJECTIVE: To systematically review all studies that developed or validated a vaginal birth after cesarean (VBAC) prediction model. DATA SOURCES: MEDLINE, EMBASE, CINAHL, Cochrane Library, and ClinicalTrials.gov were searched from inception until February 2022. METHODS OF STUDY SELECTION: We included observational studies that developed or validated a multivariable VBAC prediction model in women with a singleton pregnancy and one previous lower segment cesarean delivery. A total of 3,758 articles were identified and screened. TABULATION, INTEGRATION, AND RESULTS: For 57 included studies, data were extracted in duplicate using a CHARMS (Critical Appraisal and Data Extraction for Systematic Review of Prediction Modelling Studies) checklist-based tool and included participants' characteristics, sample size, predictors, timing of application, and performance. PROBAST (Prediction model Risk of Bias Assessment Tool) and TRIPOD (Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis) were used to assess risk of bias and transparency of reporting. Several studies developed or validated more than one model. There were 38 unique prediction models, 42 external validations of 10 existing prediction models, and six modifications of existing models. Of the 38 unique models, only 19 (19/38, 50%) were internally validated in the initial study. No studies externally validated their model in the initial study. Age, previous vaginal birth, and previous cesarean delivery for labor dystocia were the commonest predictors. The area under the curve in included studies ranged from 0.61 to 0.95. Models used close to delivery generally outperformed those used earlier in pregnancy. Most studies demonstrated a high risk of bias (45/57, 79%), the remainder were unclear (7/57, 12%) and low (5/57, 9%). Median TRIPOD checklist adherence was 70% (range 32-93%). CONCLUSION: Several prediction models for VBAC success exist, but many lack external validation and are at high risk of bias. Models used close to delivery outperformed those used earlier in pregnancy; however, their generalizability and applicability remain unclear. High-quality external validation and effect studies are required to guide clinical use. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42020190930.

Electronic Patient Reported Outcomes for Miscarriage Research in Tommy's Net.

The Tommy's National Centre for Miscarriage Research aims to support the diagnosis and treatment for couples suffering from recurrent miscarriage. Tommy's Net is an electronic data gathering tool, collecting miscarriage data and links with hospital Clinical Information System databases. The gathering of patient reported data is an important aspect, especially as data relating to pregnancy and miscarriage events are often left unreported. METHODS: Both traditional paper-based and electronic patient reported outcome (ePRO) solutions have been explored to improve response rates, minimize data redundancy and reduce burden on staff. Popular ePRO survey solutions have been compared, including REDCap, SurveyMonkey, Qualtrics and LimeSurvey. RESULTS: LimeSurvey was selected as the most appropriate solution as it provided self-hosting capability, SMS integration and ease of use. CONCLUSION: We have implemented a LimeSurvey based ePRO system for collection of baseline and follow-up data for participants on the Tommy's study.