The Soleymani and Collins Obstetric morbidity score (SaCOMS): A quantitative tool for measuring maternal morbidity from complex obstetric surgery such as placenta accreta spectrum (PAS).

It is currently very difficult to compare different management strategies for complex obstetric surgery, such as hysterectomy for severe Placenta Accreta Spectrum (PAS), as there is no widely accepted consensus for the classification of maternal surgical morbidity. Many studies focus on the amount of blood products transfused or admission to intensive care units (ICU). However, these are dependent on local policies and available resources. It also gives an incomplete representation of the entire 'patient journey' after they leave the operating room. Subsequent repeat procedures for lower urinary track damage is arguably worse from the woman's perspective than a short stay on an intensive care unit (ICU) for observation. We suggest a version of the Clavien-Dindo morbidity classification specific to obstetrics. Then employ it to build a quantitative morbidity score which aims to reflect the whole 'patient experience' including the post-operative pathway. We then demonstrate the utility of this system in a cohort of women with Placenta Accreta Spectrum (PAS). The Clavien-Dindo classification was modified to reflect obstetric procedures and a quantitative morbidity measure, the Soleymani and Collins Obstetric Morbidity Score (SaCOMS), was developed based on this. Both were then validated using a survey-based consultation of a panel of experts in PAS and retrospectively applied to a cohort of 54 women who underwent caesarean hysterectomy for PAS. Clinicians with expertise in PAS believe that the Modified Obstetric Clavien-Dindo classification system and the novel SaCOMS tool can improve assessment of maternal morbidity, and better reflect the 'patient experience'. Application of the classification system to a single-centre PAS cohort suggested that surgery by gynecologic-oncology surgeons may be associated with decreased incidence and cumulative morbidity outcomes for women with PAS, especially those with the most severe presentation. This study presents a clinically useful obstetric-specific classification system for surgical morbidity. SaCOMS also provides a quantitative reflection of the full patient- journey experienced as a result of surgical complications enabling a more patient-centered representation of morbidity.

Accuracy of sonographic lower segment thickness and prediction of vaginal birth after caesarean in a resourced-limited setting; Prospective study.

OBJECTIVES: To assess the accuracy of ultrasound measurement of the lower uterine segment (LUS) thickness against findings at laparotomy, and to investigate its correlation with the success rate of vaginal birth after one previous caesarean delivery (CD) in a resource-limited setting. DESIGN: Prospective study. SETTING: Obstetrics and Gynaecology department in a tertiary hospital in Ghana. POPULATION: Women with one previous CD undergoing either a trial of labour (TOLAC) or elective CD. METHODS: Myometrial lower uterine segment thickness (mLUS) and full lower uterine segment thickness (fLUS) were measured with transvaginal ultrasound (TVUS). The women were managed according to local protocols with the clinicians blinded to the ultrasound measurements. The LUS was measured intraoperatively for comparison with ultrasound measurements. MAIN OUTCOME MEASURES: Lower uterine segment findings at laparotomy, successful vaginal birth. RESULTS: A total of 311 pregnant women with one previous CD were enrolled; 147 women underwent elective CD and 164 women underwent a TOLAC. Of the women that underwent TOLAC, 96 (58.5%) women had a successful vaginal birth. The mLUS was comparable to the intraoperative measurement in the elective CD group with LUS thickness <5 mm (bias of 0.01, 95% CI -0.10 to 0.12 mm) whereas fLUS overestimated LUS <5 mm (bias of 0.93, 95% CI 0.80-1.06 mm). Successful vaginal birth rate correlated with increasing mLUS values (odds ratio 1.30, 95% CI 1.03-1.64). Twelve cases of uterine defect were recorded. LUS measurement ≤2.0 mm was associated with an increased risk of uterine defects with a sensitivity of 91.7% (95% CI 61.5-99.8%) and specificity of 81.8% (95% CI 75.8-86.8%). CONCLUSION: Accurate TVUS measurement of the LUS is technically feasible in a resource-limited setting. This approach could help in making safer decisions on mode of birth in limited-resource settings.

Differentiating placenta accreta spectrum from scar dehiscence with underlying, non-adherent placenta: A systematic review of scoring systems and primary data analysis.

INTRODUCTION: Accurate discrimination between placenta accreta spectrum (PAS) and scar dehiscence with underlying non-adherent placenta is challenging both on prenatal ultrasound and intraoperatively. This can lead to overdiagnosis of PAS and unnecessarily aggressive management of scar dehiscence which increases the risk of morbidity. Several scoring systems have been published which combine clinical and ultrasound information to help diagnose PAS in women at high risk. This research aims to provide insights into the reliability and utility of existing accreta scoring systems in differentiating these two closely related but different conditions to contribute to improved clinical decision making and patient outcomes. MATERIAL AND METHODS: A literature search was performed in four electronic databases. The references of relevant articles were also assessed. The articles were then evaluated according to the predefined inclusion criteria. Primary data for testing each scoring system were obtained retrospectively from two hospitals with specialized PAS services. Each scoring system was used to evaluate the predicted outcome of each case. RESULTS: The literature review yielded 15 articles. Of these, eight did not have a clearly described diagnostic criteria for accreta, hence were excluded. Of the remaining seven studies, one was excluded due to unorthodox diagnostic criteria and two were excluded as they differed from the other systems hindering comparison. Four scoring systems were therefore tested with the primary data. All the scoring systems demonstrated higher scores for high-grade PAS compared to scar dehiscence (p < 0.001) with an excellent Area Under the receiver operator characteristic Curve ranging from 0.82 (95% CI 0.71-0.92) to 0.87 (95% CI 0.79-0.96) in differentiating between these two conditions. However, no statistically significant differences were noted between the low-grade PAS and scar dehiscence on all scoring systems. CONCLUSIONS: Most published scoring systems have no clearly defined diagnostic criteria. Scoring systems can differentiate between scar dehiscence with underlying non-adherent placenta from high-grade PAS with excellent diagnostic accuracy, but not for low-grade PAS. Hence, relying solely on these scoring systems may lead to errors in estimating the risk or extent of the condition which hinders preoperative planning.

Three-dimensional volume rendering ultrasound for assessing placenta accreta spectrum severity and discriminating it from simple scar dehiscence.

BACKGROUND: Prenatal ultrasound discrimination between placenta accreta spectrum and scar dehiscence with underlying nonadherent placenta is challenging both prenatally and intraoperatively, which often leads to overtreatment. In addition, accurate prenatal prediction of surgical difficulty and morbidity in placenta accreta spectrum is difficult, which precludes appropriate multidisciplinary planning. The advent of advanced 3-dimensional volume rendering and contrast enhancement techniques in modern ultrasound systems provides a comprehensive prenatal assessment, revealing details that are not discernible in traditional 2-dimensional imaging. OBJECTIVE: This study aimed to evaluate the use of 3-dimensional volume rendering ultrasound techniques in determining the severity of placenta accreta spectrum and distinguishing between placenta accreta spectrum and scar dehiscence with underlying nonadherent placenta. STUDY DESIGN: A prospective, cohort study was conducted between July 2022 and July 2023 in the fetal medicine unit of Dr Soetomo Academic General Hospital, Surabaya, Indonesia. All pregnant individuals with anterior low-lying placenta or placenta previa with a previous caesarean section who were referred with suspicion of placenta accreta spectrum were consented and screened using the standardised 2-dimensional and Doppler ultrasound imaging. Additional 3-dimensional volumes were obtained from the sagittal section of the uterus with a filled urinary bladder. These were analyzed by rotating the region of interest to be perpendicular to the uterovesical interface. The primary outcomes were the clinical and histologic severity in the cases of placenta accreta spectrum and correct diagnosis of dehiscence with nonadherent placenta underneath. The strength of association between ultrasound and clinical outcomes was determined. Multivariate logistic regression analyses and diagnostic testing of accuracy were used to analyze the data. RESULTS: A total of 70 patients (56 with placenta accreta spectrum and 14 with scar dehiscence) were included in the analysis. Multivariate logistic regression of all 2-dimensional and 3-dimensional signs revealed the 3-dimensional loss of clear zone (P<.001) and the presence of bridging vessels on 2-dimensional Doppler ultrasound (P=.027) as excellent predictors in differentiating scar dehiscence and placenta accreta spectrum. The 3-dimensional loss of clear zone demonstrated a high diagnostic accuracy with an area under the curve of 0.911 (95% confidence interval, 0.819-1.002), with a sensitivity of 89.3% (95% confidence interval, 78.1-95.97%) and specificity of 92.9% (95% confidence interval, 66.1-99.8%). The presence of bridging vessels on 2-dimensional Doppler demonstrated an area under the curve of 0.848 (95% confidence interval, 0.714-0.982) with a sensitivity of 91.1% (95% confidence interval, 80.4-97.0%) and specificity of 78.6% (95% confidence interval, 49.2-95.3%). A subgroup analysis among the placenta accreta spectrum group revealed that the presence of a 3-dimensional disrupted bladder serosa with obliteration of the vesicouterine space was associated with vesicouterine adherence (P<.001). CONCLUSION: Three-dimensional volume rendering ultrasound is a promising tool for effective discrimination between scar dehiscence with underlying nonadherent placenta and placenta accreta spectrum. It also shows potential in predicting the clinical severity with urinary bladder involvement in cases of placenta accreta spectrum.

3D Single Vessel Fractional Moving Blood Volume (3D-svFMBV): Fully Automated Tissue Perfusion Estimation Using Ultrasound.

Power Doppler ultrasound (PD-US) is the ideal modality to assess tissue perfusion as it is cheap, patient-friendly and does not require ionizing radiation. However, meaningful inter-patient comparison only occurs if differences in tissue-attenuation are corrected for. This can be done by standardizing the PD-US signal to a blood vessel assumed to have 100% vascularity. The original method to do this is called fractional moving blood volume (FMBV). We describe a novel, fully-automated method combining image processing, numerical modelling, and deep learning to estimate three-dimensional single vessel fractional moving blood volume (3D-svFMBV). We map the PD signals to a characteristic intensity profile within a single large vessel to define the standardization value at the high shear vessel margins. This removes the need for mathematical correction for background signal which can introduce error. The 3D-svFMBV was first tested on synthetic images generated using the characteristics of uterine artery and physiological ultrasound noise levels, demonstrating prediction of standardization value close to the theoretical ideal. Clinical utility was explored using 143 first-trimester placental ultrasound volumes. More biologically plausible perfusion estimates were obtained, showing improved prediction of pre-eclampsia compared with those generated with the semi-automated original 3D-FMBV technique. The proposed 3D-svFMBV method overcomes the limitations of the original technique to provide accurate and robust placental perfusion estimation. This not only has the potential to provide an early pregnancy screening tool but may also be used to assess perfusion of different organs and tumors.

Absence of abnormal vascular changes on prenatal imaging aids in differentiating simple uterine scar dehiscence from placenta accreta spectrum: a case series.

Accurate prenatal discrimination between a simple, non-adherent uterine scar dehiscence with an underlying placenta and the severe end of the placenta accreta spectrum is problematic as the two can appear similar on prenatal imaging. This may lead to the false diagnosis of placenta accreta spectrum resulting obstetric anxiety, overtreatment and potential iatrogenic morbidity. Despite potential similarities in the etiology, the manifestation and management of these two conditions is very different. The prenatal sonographic features of seven confirmed cases of simple uterine scar dehiscence with an underlying placenta previa were examined. The common sonographic features found for scar dehiscence was a thinned myometrium (<1 mm) overlying a generally homogenous placenta and a placental bulge. There was absence of lacunae and features of hypervascularity including bridging vessels. Our findings suggest accurate discrimination between a simple scar dehiscence with the placenta underlying it and placenta accreta spectrum can be made on prenatal ultrasound if the placenta is carefully examined for the vascular features unique to PAS.

Ultrasound discrimination between placenta accreta spectrum and urinary bladder varices.

Distinguishing between urinary bladder varices and retroplacental neovascularization in placenta accreta spectrum in high-risk patients with placental previa is a diagnostic challenge since they have similar appearances on prenatal ultrasound. Placenta accreta spectrum is associated with massive obstetric haemorrhage while the presence of urinary bladder varices in pregnancy poses a lower surgical risk. Since the clinical implications and management approach for both conditions are entirely different, false positive diagnoses have iatrogenic consequences. In this article, we share our experiences in differentiating these two phenomena on prenatal ultrasound supported by ultrasound and intraoperative images.

Kasr Alainy simplified uterine preserving surgery for conservative management of placenta accreta spectrum (PAS): A modified surgical approach.

OBJECTIVE: The incidence of placenta accreta spectrum (PAS) is rising rapidly due to the global surge in Caesarean delivery. It is associated with significant maternal morbidity and mortality. It is usually managed with Caesarean hysterectomy. However, uterine preserving surgeries can have advantages over Caesarean hysterectomy and intentional placental retention techniques. STUDY DESIGN: We present a modified technique of uterine preserving surgery that uses a safe approach for placental bed surgical devascularization. This is followed by resection of the invaded uterine segment and uterine wall reconstruction. RESULTS: The technique was used in the management of 20 patients with antenatally suspected PAS that were confirmed at laparotomy. It was successful in preserving the uterus in 18/20 (90 %) women. The mean intraoperative blood loss in was 1305 CC (SD: +361.6) with a mean operative time of 123 min (SD: ±38.7). There was only one urinary bladder injury and no other maternal morbidity. CONCLUSION: Our surgical technique is safe and may be useful for conservative surgical management of PAS, particularly in low- and middle-income countries, where access to complex resources, such as interventional radiology, is limited.

A simple guide to ultrasound screening for placenta accreta spectrum for improving detection and optimizing management in resource limited settings.

Placenta accreta spectrum is a pregnancy complication associated with severe morbidity and maternal mortality especially when not suspected antenatally and appropriate management instigated. Women in resource-limited settings are more likely to face adverse outcomes due to logistic, technical, and resource inadequacies. Accurate prenatal imaging is an important step in ensuring good outcomes because it allows adequate preparation and an appropriate management approach. This article provides a simple three-step approach aimed at guiding clinicians and sonographers with minimal experience in placental accreta spectrum through risk stratification and basic prenatal screening for this condition both with and without Doppler ultrasound.

A Risk-Prediction Model for Placenta Accreta Spectrum Severity From Standardized Ultrasound Markers.

We aimed to generate a model to predict the risk of a woman having normal, abnormally adherent (AAP) or abnormally invasive placentation (AIP) based on the presence of recently codified ultrasound (US) markers and disease definitions of placenta accreta spectrum (PAS). We recruited women with anterior low-lying placenta or placenta previa and a history of previous caesarean delivery to a prospective cohort study. US markers of abnormal placentation were recorded on a standardized pro forma. The presence and International Federation of Gynecology and Obstetrics grade of PAS was evaluated clinically and histologically at delivery. Markers demonstrating a predictive relationship to PAS were incorporated into a logistic regression model. A total of 106 women were included, of whom 42 (40%) were normal, 24 (23%) had AAP and 40 (38%) had AIP. A model including just four key variables (loss of clear zone, abnormal placental lacunae, placental bulge and bladder wall interruption) was shown to reliably predict presence and severity of PAS, with an optimism-corrected C-index of 0.901. A simple model incorporating four US markers can predict likelihood and severity of PAS with high accuracy. This is the first time this has been demonstrated using the recently codified definitions of the US signs and disease definitions. Further work will see our model applied prospectively to a large patient cohort, ideally through a smartphone-based application, for external validation.

Placenta accreta spectrum - variations in clinical practice and maternal morbidity between the UK and France: a population-based comparative study.

OBJECTIVE: To compare the management and outcomes of women with placenta accreta spectrum (PAS) in France and the UK. DESIGN: Two population-based cohorts. SETTING: All obstetrician-led hospitals in the UK and maternity hospitals in eight French regions. POPULATION: A cohort of 219 women with PAS in France and a cohort of 154 women with PAS in the UK. METHODS: The management and outcomes of women with PAS were compared between the UK and France. MAIN OUTCOME MEASURES: Median blood loss, severe postpartum haemorrhage (≥3 l), postpartum infection and damage to surrounding organs. RESULTS: The management of PAS differed between the two countries: a larger proportion of women with PAS in the UK had a caesarean hysterectomy compared with France (43% vs 26%, p < 0.001), whereas in France a larger proportion of women with PAS received a uterus-preserving approach compared with the UK (36% vs 19%, p < 0.001). The total median blood loss in the UK was 3 l (IQR 1.7-6.5 l), compared with 1 l (IQR 0.5-2.5 l) in France; more women with PAS had a severe postpartum haemorrhage (PPH) in the UK compared with women with PAS in France (58% vs 21%, p < 0.001) [Correction added on 06 May 2022, after first online publication: '24 hour' has been changed to 'total' in the preceding sentence]. There was no difference between the UK and French populations for postpartum infection or organ damage. CONCLUSIONS: The UK and France have very different approaches to managing PAS, with more women in France receiving a uterine-conserving approach and more women in the UK undergoing caesarean hysterectomy. A life-threatening haemorrhage was more common in the UK than in France, which may be the result of differential management and/or the organisation of the healthcare systems. In women with placenta accreta spectrum, severe haemorrhage was more common in the UK than in France. TWEETABLE ABSTRACT: In women with placenta accreta spectrum, severe haemorrhage was more common in the UK than in France.

When a rare condition creates a scientific society: The history of the International Society for Placenta Accreta Spectrum (IS-PAS).

Almost 10 years ago, clinicians at multiple locations all over Europe observed an increased number of antenatally undiagnosed cases of placenta accreta spectrum (PAS) resulting in significant morbidity and the occasional maternal death. Even with an improvement in antenatal imaging, the management of severe PAS remains challenging. One solution to improve understanding in rare but potentially lethal conditions is international collaboration. Consequently, a European working group was formed, which over the next few years grew into an international society, the IS-PAS. The collective goals are to develop a large shared database of cases, generate high-quality research into all aspects of PAS, and improve education of both healthcare professionals and patients. The first results of this collaboration are presented within this supplement.

The relation between maternal obesity and placenta accreta spectrum: A multinational database study.

INTRODUCTION: It has been suggested that women with obesity have increased risk of developing placenta accreta spectrum (PAS). It is unclear if this is independent of the increased risk of cesarean delivery seen with obesity itself. The aim of this study was to explore the association between maternal obesity and PAS, particularly severe PAS (percreta). MATERIAL AND METHODS: This is a cohort study based on cases recorded in the International Society for Placenta Accreta Spectrum (IS-PAS) database between April 2008 and May 2019. Multivariable logistic regression was used to explore the effect of maternal obesity on severity of PAS; this model was adjusted for other known risk factors including previous cesarean deliveries, maternal age, and placenta previa. The estimated rate of obesity in a hypothetical cohort with similar characteristics (previous cesarean delivery and same parity) was calculated and compared with the observed rate of obesity in the women of the PAS cohort (one sample test of proportions). RESULTS: Of the 386 included women with PAS, 227 (58.8%) had severe disease (percreta). In univariable analysis, maternal obesity initially appeared to be associated with increased odds of developing the most severe type of PAS, percreta (odds ratio [OR] 1.87; 95% CI 1.14-3.09); however, this association was lost after adjustment for other risk factors including previous cesarean delivery (OR 1.44; 95% CI 0.85-2.44). There was no difference in the observed rate of obesity and the rate estimated based on the risk of cesarean delivery from obesity alone (31.3% vs 36.8%, respectively; P = .07). CONCLUSIONS: Obesity does not seem to be an independent risk factor for PAS or severity for PAS. These findings are relevant for clinicians to provide accurate counseling to women with obesity regarding increased risks related to pregnancy.

The modified radical peripartum cesarean hysterectomy (Soleymani-Alazzam-Collins technique): a systematic, safe procedure for the management of severe placenta accreta spectrum.

BACKGROUND: The prevalence of placenta accreta spectrum is rising worldwide. The severe end of the spectrum where the placenta has invaded other organs is fortunately rare, however, few surgical techniques for such a complex hysterectomy have been described in the literature. OBJECTIVE: This study aimed to describe a stepwise, systematic technique for radical cesarean hysterectomy for placenta accreta spectrum to investigate outcomes for women with severe, invasive placenta accreta spectrum who were hysterectomized using this technique. STUDY DESIGN: This was a retrospective cohort study undertaken at a large UK tertiary referral center. A total of 24 cases of elective primary cesarean hysterectomy with a confirmed intrapartum diagnosis of severe percreta (Federation of Gynecology and Obstetrics grades 3b and 3c) were identified between 2011 and 2020. Among those cases, 16 had standard care (surgical technique dependent on surgeon's preference), and 8 had a radical peripartum hysterectomy using the Soleymani-Alazzam-Collins technique as described. Nonparametric testing was used because of sample size. RESULTS: The Soleymani-Alazzam-Collins technique resulted in significantly less blood loss (P=.032), more transverse incisions (P=.009), and less intensive care unit admissions (P=.046). Furthermore, there was no significant difference in theater time. CONCLUSION: The Soleymani-Alazzam-Collins technique demonstrated a significant improvement in outcomes for women with severe placenta accreta spectrum, without increasing surgical time.

Maternal and neonatal outcomes in planned versus emergency cesarean delivery for placenta accreta spectrum: A multinational database study.

INTRODUCTION: Placenta accreta spectrum (PAS) is a condition often resulting in severe maternal morbidity. Scheduled delivery by an experienced team has been shown to improve maternal outcomes; however, the benefits must be weighed against the risk of iatrogenic prematurity. The aim of this study is to investigate the rates of emergency delivery seen for antenatally suspected PAS and compare the resulting outcomes in the 15 referral centers of the International Society for PAS (IS-PAS). MATERIAL AND METHODS: Fifteen centers provided cases between 2008 and 2019. The women included were divided into two groups according to whether they had a planned or an emergency cesarean delivery. Delivery was defined as "planned" when performed at a time and date to suit the team. All the remaining cases were classified as "emergency". Maternal characteristics and neonatal outcomes were compared between the two groups according to gestation at delivery. RESULTS: In all, 356 women were included. Of these, 239 (67%) underwent a planned delivery and 117 (33%) an emergency delivery. Vaginal bleeding was the indication for emergency delivery in 41 of the 117 women (41%). There were no significant differences in terms of blood loss, transfusion rates or major maternal morbidity between planned and emergency deliveries. However, the rate of maternal intensive therapy unit admission was increased with emergency delivery (45% vs 33%, P = .02). Antepartum hemorrhage was the only independent predictor of emergency delivery (aOR: 4.3, 95% confidence interval 2.4-7.7). Emergency delivery due to vaginal bleeding was more frequent with false-positive cases (antenatally suspected but not confirmed as PAS at delivery) and the milder grades of PAS (accreta/increta). The rate of infants experiencing any major neonatal morbidity was 25% at 34+1 to 36+0  weeks and 19% at >36+0  weeks. CONCLUSIONS: Emergency delivery in centers of excellence did not increase blood loss, transfusion rates or maternal morbidity. The single greatest risk factor for emergency delivery was antenatal hemorrhage. When adequate expertise and resources are available, to defer delivery in women with no significant antenatal bleeding and no risk factors for pre-term birth until >36+0  weeks can be considered to improve fetal outcomes. Further studies are needed to investigate this fully.

Understanding the uterine artery Doppler waveform and its relationship to spiral artery remodelling.

Analysis of the uterine artery (UtA) Doppler waveform is frequently used in high-risk pregnancies to assess the likelihood of adverse pregnancy outcomes, including preeclampsia and fetal growth restriction. Whilst abnormal UtA waveforms at 18-20 weeks are associated with adverse outcomes, the underlying cause of these waveform changes remains unknown. Current evidence suggests the long-held dogma that the UtA waveform is merely a reflection of trophoblast-induced spiral artery remodelling is incorrect. Hence, the origins of the waveform changes must be reassessed. Recent data from human and animal models suggests that the arcuate arteries, placental bed arterio-venous anastomoses and, most notably, the radial arteries may be more important in determining the UtA waveform profile than previously appreciated. Furthermore, there is increasing evidence implicating the maternal cardiovascular system in the pathophysiology of the complications predicted by the waveform changes, particularly preeclampsia, and therefore its underlying association with the UtA waveform warrants further investigation.

Fully Automated 3-D Ultrasound Segmentation of the Placenta, Amniotic Fluid, and Fetus for Early Pregnancy Assessment.

Volumetric placental measurement using 3-D ultrasound has proven clinical utility in predicting adverse pregnancy outcomes. However, this metric cannot currently be employed as part of a screening test due to a lack of robust and real-time segmentation tools. We present a multiclass (MC) convolutional neural network (CNN) developed to segment the placenta, amniotic fluid, and fetus. The ground-truth data set consisted of 2093 labeled placental volumes augmented by 300 volumes with placenta, amniotic fluid, and fetus annotated. A two-pathway, hybrid (HB) model using transfer learning, a modified loss function, and exponential average weighting was developed and demonstrated the best performance for placental segmentation (PS), achieving a Dice similarity coefficient (DSC) of 0.84- and 0.38-mm average Hausdorff distances (HDAV). The use of a dual-pathway architecture improved the PS by 0.03 DSC and reduced HDAV by 0.27 mm compared with a naïve MC model. The incorporation of exponential weighting produced a further small improvement in DSC by 0.01 and a reduction of HDAV by 0.44 mm. Per volume inference using the FCNN took 7-8 s. This method should enable clinically relevant morphometric measurements (such as volume and total surface area) to be automatically generated for the placenta, amniotic fluid, and fetus. The ready availability of such metrics makes a population-based screening test for adverse pregnancy outcomes possible.

Caesarean delivery rates and analgesia effectiveness following injections of sterile water for back pain in labour: A multicentre, randomised placebo controlled trial.

BACKGROUND: About a third of women experience severe back pain during labour. Injecting small volumes of intracutaneous sterile water into the lumbar region can be used to relieve this pain, however the procedure is controversial and previous reviews call for high quality trials to establish efficacy. We evaluated the impact on birth outcomes and analgesic effects of sterile water injections. METHODS: A multicentre, double-blind trial undertaken between December 2012 and December 2017 in one British and 15 Australian maternity units. Women experiencing severe back-pain in labour were assigned (1:1) by an independently generated randomisation schedule stratified by site to injections of either sterile water or saline placebo. Participants and caregivers were blinded to group allocation. The primary outcome was caesarean delivery rate. Main secondary outcomes included at least 30% or 50% reduction in self-reported pain scores at 30, 60 and 90 minutes after treatment. Intention to treat analysis were used and the level of significance for the multiple clinical outcomes was set at p<0.001 with the Bonferroni correction applied. The study is registered with the ACTRN Registry number, ACTRN1261100022195. FINDINGS: Between December 9, 2012, and December 15, 2017, 1166 women were recruited and randomised: 587 women received sterile water injections (SWI) and 579 a saline placebo. Seven women in the SWI group and 12 in the placebo group were excluded as consent was not completed, leaving 580 and 567, respectively, included in the analysis. The proportions of caesarean delivery were 17·1% (82 of 580) in the SWI group and 14·8% (82 of 567) in the placebo (RR 1·16, 95% CI 0·88-1.51; p = 0·293). At 30 min post treatment 60·8% (330 of 543) of women in the SWI group reported a 30% reduction in self-reported pain compared to 31·4% (163 of 520) placebo (RR 1·94, 95% CI 1·68-2·24; p=<0·001) and 43·3% (235 of 534) SWI reported a 50% reduction versus 18·1% (94 of 520) placebo (RR 2·39, 95% CI 1·95-2·94; p=<0·001). The analgesic effect of SWI compared to placebo remained significant at 60 and 90 min post-treatment. There were no significant differences in other maternal or neonatal outcomes. INTERPRETATION: Compared to placebo, injections of sterile water did not reduce rates of caesarean delivery. For the main secondary outcome of pain relief the intervention did result in significantly more women reporting at least 30% and 50% reduction in pain for up to 90 min. Water injections have no effect on birth outcomes though can be an effective treatment for the relief of labour-related back pain.Funded by the National Health and Medical Research Council.