Consensus protocol for management of early and late twin-twin transfusion syndrome: Delphi study

OBJECTIVE

Fetoscopic laser photocoagulation (FLP) is a well-established treatment for twin-twin transfusion syndrome (TTTS) between 16 and 26 weeks' gestation. High-quality evidence and guidelines regarding the optimal clinical management of very early (prior to 16 weeks), early (between 16 and 18 weeks) and late (after 26 weeks) TTTS are lacking. The aim of this study was to construct a structured expert-based clinical consensus for the management of early and late TTTS.

METHODS

A Delphi procedure was conducted among an international panel of experts. Participants were chosen based on their clinical expertise, affiliation and relevant publications. A four-round Delphi survey was conducted using an online platform and responses were collected anonymously. In the first round, a core group of experts was asked to answer open-ended questions regarding the indications, timing and modes of treatment for early and late TTTS. In the second and third rounds, participants were asked to grade each statement on a Likert scale (1, completely disagree; 5, completely agree) and to add any suggestions or modifications. At the end of each round, the median score for each statement was calculated. Statements with a median grade of 5 without suggestions for change were accepted as the consensus. Statements with a median grade of 3 or less were excluded from the Delphi process. Statements with a median grade of 4 were modified according to suggestions and reconsidered in the next round. In the last round, participants were asked to agree or disagree with the statements, and those with more than 70% agreement without suggestions for change were considered the consensus.

RESULTS

A total of 122 experts met the inclusion criteria and were invited to participate, of whom 53 (43.4%) agreed to take part in the study. Of those, 75.5% completed all four rounds. A consensus on the optimal management of early and late TTTS was obtained. FLP can be offered as early as 15 weeks' gestation for selected cases, and can be considered up to 28 weeks. Between 16 and 18 weeks, management should be tailored according to Doppler findings.

CONCLUSIONS

A consensus-based treatment protocol for early and late TTTS was agreed upon by a panel of experts. This protocol should be modified at the discretion of the operator, according to their experience and the specific demands of each case. This should advance the quality of future studies, guide clinical practice and improve patient care. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Non-Invasive Glucose Sensing Technologies and Products: A Comprehensive Review for Researchers and Clinicians

Diabetes Mellitus incidence and its negative outcomes have dramatically increased worldwide and are expected to further increase in the future due to a combination of environmental and social factors. Several methods of measuring glucose concentration in various body compartments have been described in the literature over the years. Continuous advances in technology open the road to novel measuring methods and innovative measurement sites. The aim of this comprehensive review is to report all the methods and products for non-invasive glucose measurement described in the literature over the past five years that have been tested on both human subjects/samples and tissue models. A literature review was performed in the MDPI database, with 243 articles reviewed and 124 included in a narrative summary. Different comparisons of techniques focused on the mechanism of action, measurement site, and machine learning application, outlining the main advantages and disadvantages described/expected so far. This review represents a comprehensive guide for clinicians and industrial designers to sum the most recent results in non-invasive glucose sensing techniques' research and production to aid the progress in this promising field.

Short-Term Effects of Dexamethasone versus Betamethasone on Ultrasonic Measures of Fetal Well-Being: Cohort from a Blinded, Randomized Trial

INTRODUCTION

Maternal corticosteroid administration for anticipated preterm birth is common; however, the corticosteroid effect on fetal ultrasound and cardiotocograph (CTG) remains contested. This study aimed to evaluate short-term ultrasound and CTG impact of (a) dexamethasone versus betamethasone (b) pooled corticosteroid effect.

METHODS

Substudy of blinded randomized trial of dexamethasone versus betamethasone (given <34 weeks). Umbilical artery (UA), middle cerebral artery (MCA), ductus venosus (DV), and uterine artery Doppler, myocardial performance index (MPI), biophysical profile (BPP), and CTG measured pre-corticosteroid then 1, 2, 4, and 7 days post-corticosteroid.

RESULTS

Of 47 fetuses (39 singleton; 4 dichorionic, diamniotic twins; and 4 monochorionic, diamniotic twins) in the February 2012-2013 period, 24 received dexamethasone and 23 betamethasone at average gestation 29.8 ± 2.9 weeks. Thirteen pregnancies (30%) had pre-corticosteroid fetal concerns (estimated weight <10th centile and/or abnormal UA/MCA Doppler). Few significant differences were seen post-corticosteroid: DV pulsatility index and right MPI initially decreased 15-20%, and average BPP decreased slightly on days 1-2. There were no major differential effects of dexamethasone versus betamethasone.

DISCUSSION/CONCLUSION

No substantive post-corticosteroid effects were seen for most ultrasound/CTG measures in fetuses with heightened preterm birth risk but predominantly normal pre-corticosteroid measures. Clinically, this suggests avoiding overreliance on individual measures for delivery decisions post-corticosteroid; equally, multiple/marked ultrasound changes suggest true pathology and not corticosteroid effect.

Multi-Parametric Fusion of 3D Power Doppler Ultrasound for Fetal Kidney Segmentation Using Fully Convolutional Neural Networks

Kidney development is key to the long-term health of the fetus. Renal volume and vascularity assessed by 3D ultrasound (3D-US) are known markers of wellbeing, however, a lack of real-time image segmentation solutions preclude these measures being used in a busy clinical environment. In this work, we aimed to automate kidney segmentation using fully convolutional neural networks (fCNNs). We used multi-parametric input fusion incorporating 3D B-Mode and power Doppler (PD) volumes, aiming to improve segmentation accuracy. Three different fusion strategies and their performance were assessed versus a single input (B-Mode) network. Early input-level fusion provided the best segmentation accuracy with an average Dice similarity coefficient (DSC) of 0.81 and Hausdorff distance (HD) of 8.96 mm, an improvement of 0.06 DSC and reduction of 1.43 mm HD compared to our baseline network. Compared to manual segmentation for all models, repeatability was assessed by intra-class correlation coefficients (ICC) indicating good to excellent reproducibility (ICC 0.93). The framework was extended to support multiple graphics processing units (GPUs) to better handle volumetric data, dense fCNN models, batch normalization and complex fusion networks. This work and available source code provides a framework to increase the parameter space of encoder-decoder style fCNNs across multiple GPUs and shows that application of multi-parametric 3D-US in fCNN training improves segmentation accuracy.

Bimanual examination for clot evacuation: a retrospective cohort study of women with postpartum haemorrhage after vaginal delivery

BACKGROUND

Bimanual clot evacuation (BCE) is a simple clinical manoeuvre that may reduce need for surgical intervention in the management of severe postpartum haemorrhage (PPH). We sought to determine whether performing BCE in cases of severe PPH after vaginal birth reduces the need for surgical intervention.

METHODS

A retrospective chart review of women who delivered vaginally with a severe PPH between January 1, 2011 and December 31, 2014 in a single tertiary women's hospital in Sydney, Australia was conducted. Severe PPH was classified as a blood loss ≥1000mls. The need for surgical management (including operating theatre uterine exploration or evacuation, intrauterine balloon tamponade, repair of significant trauma, uterine or internal iliac artery ligation, B-Lynch suture insertion or hysterectomy) was the primary outcome measure, as expressed by need for operating theatre utilisation.

RESULTS

From a cohort of 438, 149 women (34.0%) had BCE, of whom 29 (19.5%) required surgical management compared to 103 of 289 women with no BCE (35.6%); an odds ratio (OR) of 0.38 for BCE (confidence interval 0.20-0.72; p = 0.003). Early BCE (< 1 h of delivery) was associated with a further reduction in surgery (OR 0.24; confidence interval 0.08-0.70; p = 0.009) compared to late BCE (> 1 h of delivery). There was no reduction in estimated blood loss (p = 0.86) or blood transfusion (p = 0.71) with BCE.

CONCLUSION

Our study suggests BCE reduces theatre utilisation in the context of severe PPH following vaginal delivery. Prospective trials are needed to determine whether BCE should be endorsed as a treatment modality for PPH post-vaginal delivery.

Feasibility of image registration and fusion for evaluation of structure and perfusion of the entire second trimester placenta by three-dimensional power Doppler ultrasound

BACKGROUND

Placental perfusion can be evaluated by 3D power Doppler ultrasound (3D PD-US), particularly using the validated tool 3D Fractional Moving Blood Volume (3D-FMBV); however regional variability and size limitations beyond the first trimester mean that multiple 3D PD-US volumes are required to evaluate the whole organ.

PURPOSE

We assessed the feasibility of manual offline stitching of second trimester 3D PD-US volumes of the placenta to assess whole organ perfusion using 3D-FMBV.

MATERIALS AND METHODS

This was a single-centre, prospective, observational cohort study of 36 normal second trimester singleton pregnancies with anterior placentas. 3D PD-US placental volumes were manually segmented offline and stitched together by rigid registration using manually selected, pair-wise coordinates. Data acquisition and offline volume segmentation and stitching were triplicated by a single observer with Dice similarity coefficient (DSC) and Hausdorff distance used to assess consistency. Intraclass correlation coefficient (ICC) was used to assess intra-observer repeatability of 3D-FMBV and placental volume.

RESULTS

Acquisition and stitching success were 94% and 88%, respectively. Median time for acquisition, segmentation and stitching were 13 min, 40 min and 95 min, respectively. Median intra-observer DSCs were 0.94 and 0.88, and Hausdorff distances were 11.85 mm and 36.6 mm, for segmentations and stitching, respectively.

CONCLUSION

3D-ultrasound volume stitching of the placenta is technically feasible. Intra-observer repeatability was good to excellent for all measured parameters. This work demonstrates technical feasibility; further studies may provide the basis of an in-vivo assessment tool to measure the placenta in mid-to late pregnancy.

Three-dimensional US Fractional Moving Blood Volume: Validation of Renal Perfusion Quantification

Background Three-dimensional (3D) fractional moving blood volume (FMBV) derived from 3D power Doppler US has been proposed for noninvasive approximation of perfusion. However, 3D FMBV has never been applied in animals against a ground truth. Purpose To determine the correlation between 3D FMBV and the reference standard of fluorescent microspheres (FMS) for measurement of renal perfusion in a porcine model. Materials and Methods From February 2017 to September 2017, adult pigs were administered FMS before and after measurement of renal 3D FMBV at baseline (100%) and approximately 75%, 50%, and 25% flow levels by using US machines from two different vendors. The 3D power Doppler US volumes were converted and segmented, and correlations between FMS and 3D FMBV were made with simple linear regression (r2). Similarity and reproducibility of manual segmentation were determined with the Dice similarity coefficient and 3D FMBV reproducibility (intraclass correlation coefficient [ICC]). Results Thirteen pigs were studied with 33 flow measurements. Kidney volume (mean Dice similarity coefficient ± standard deviation, 0.89 ± 0.01) and renal segmentation (coefficient of variation = 12.6%; ICC = 0.86) were consistent. The 3D FMBV calculations had high reproducibility (ICC = 0.97; 95% confidence interval: 0.96, 0.98). The 3D FMBV per-pig correlation showed excellent correlation for US machines from both vendors (mean r2 = 0.96 [range, 0.92-1.0] and 0.93 [range, 0.78-1.0], respectively). The correlation between 3D FMBV and perfusion measured with microspheres was high for both US machines (r2 = 0.80 [P < .001] and 0.70 [P < .001], respectively). Conclusion The strong correlation between three-dimensional (3D) fractional moving blood volume (FMBV) and fluorescent microspheres indicates that 3D FMBV shows excellent correlation to perfusion and good reproducibility. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Morrell et al in this issue.

The impact of caseload midwifery, compared with standard care, on women's perceptions of antenatal care quality: Survey results from the M@NGO randomized controlled trial for women of any risk

BACKGROUND

The measurement and interpretation of patient experience is a distinct dimension of health care quality. The Midwives @ New Group practice Options (M@NGO) randomized control trial of caseload midwifery compared with standard care among women regardless of risk reported both clinical and cost benefits. This study reports participants' perceptions of the quality of antenatal care within caseload midwifery, compared with standard care for women of any risk within that trial.

METHODS

A trial conducted at two Australian tertiary hospitals randomly assigned participants (1:1) to caseload midwifery or standard care regardless of risk. Women were sent an 89-question survey at 6 weeks postpartum that included 12 questions relating to pregnancy care. Ten survey questions (including 7-point Likert scales) were analyzed by intention to treat and illustrated by participant quotes from two free-text open-response items.

RESULTS

From the 1748 women recruited to the trial, 58% (n = 1017) completed the 6-week survey. Of those allocated to caseload midwifery, 66% (n = 573) responded, compared with 51% (n = 444) of those allocated to standard care. The survey found women allocated to caseload midwifery perceived a higher level of quality care across every antenatal measure. Notably, those women with identified risk factors reported higher levels of emotional support (aOR 2.52 [95% CI 1.87-3.39]), quality care (2.94 [2.28-3.79]), and feeling actively involved in decision-making (3.21 [2.35-4.37]).

CONCLUSIONS

Results from the study show that in addition to the benefits to clinical care and cost demonstrated in the M@NGO trial, caseload midwifery outperforms standard care in perceived quality of pregnancy care regardless of risk.

A 9-year audit of fetal chest masses in an Australian maternal-fetal medicine cohort

Introduction

To assess fetal vs. neonatal diagnoses, pregnancy outcomes and need for surgery in babies prenatally diagnosed with congenital pulmonary airway malformation (CPAM) or bronchopulmonary sequestration (BPS).

Methods

Retrospective single-centre cohort study of fetuses with a prenatal diagnosis of CPAM or BPS between 2006 and 2014. Data collected included serial antenatal ultrasound information and neonatal/infant diagnoses and outcomes.

Results

Initial ultrasound diagnosis (n = 63) was CPAM in 51 and BPS in 12: nineteen (30%) fetuses had mediastinal shift and 2 (3%) had hydrops. All neonates with known birth outcome (n = 56) were liveborn. Final diagnosis in 52 infants (83%) with neonatal imaging and/or histopathology confirmed CPAM in 17/44 (39%) and BPS in 6/9 (67%). Of 34 prenatally suspected but unconfirmed CPAM lesions: 10 had no lesion on neonatal imaging, one no neonatal imaging performed, five confirmed BPS, 11 other lung/thoracic lesions, seven were lost to follow-up. There was one infant death. 27/63 infants (43%) had post-natal surgery. More neonates requiring neonatal respiratory support/resuscitation had surgery compared to those who did not (67% vs. 29%, P = 0.008). Patients with suspected CPAM or BPS on both initial and final ultrasound were more likely to have post-natal surgical management than when a lesion was no longer visible on final antenatal ultrasound (68% vs. 23%, P = 0.001).

Conclusions

Over 50% of antenatally suspected CPAM/BPS either regressed or had an alternate post-natal diagnosis. Perinatal outcome was good, with the majority of neonates/infants conservatively managed. Persistently visible antenatal lesion and need for neonatal respiratory support predicted ultimate surgical management.

Fetal abdominal wall defects in an Australian tertiary setting: contemporary characteristics, ultrasound accuracy, and outcome

PURPOSE

In this study, we aimed to comprehensively evaluate risk factors, ultrasound estimation of fetal weight, prenatal management, and pregnancy outcomes of gastroschisis and omphalocele at a metropolitan Australian hospital.

MATERIAL AND METHODS

This was a retrospective single-center cohort study from 2006 to 2014 at a tertiary hospital with colocated neonatal surgical facilities. Demographic, pregnancy, ultrasound, birth and neonatal data were compared between gastroschisis and omphalocele. Correlation between routine (Hadlock 1 &2) and specific (Siemer) estimated fetal weight (EFW) estimation formulae with birth weight (BW) was made for those 50 gastroschisis cases with ≥2 third trimester scans and last scan ≤2 weeks prior to birth.

RESULTS

There were 126 abdominal wall defects: 83 gastroschisis and 43 omphalocele. Consistent with international literature, the average maternal age was lower for gastroschisis and rates of smoking higher, while there were more intrauterine deaths and pregnancy terminations in omphalocele. Gastroschisis mothers were more likely living outside Sydney, had more infections in pregnancy and were followed with a larger number of antenatal visits, with a shorter period from the last visit to birth. In omphalocele pregnancies, amniocentesis was more likely performed, with more abnormal results than in gastroschisis fetuses. All EFW formulae had a good correlation between Z score for the last US and actual BW (ICC 0.693-0.815), with Hadlock 2 being the best. Siemer formula had the best correlation from first to the last scan. Gastroschisis newborns were born earlier (36.8 versus 38.2 wks p = .001), with smaller birthweight (2.52 versus 3.03 kg, p < .001), a longer request of intensive care (central line, parenteral nutrition, intubation) and second surgery, along with more multisystem complications (average 1.5 versus 0.7, p = .004) and a longer hospital stay (58.8 versus 36.8 d, p < .001).

CONCLUSION

Demographic, antenatal, and pregnancy outcome data for abdominal wall defects correlated well with the international literature. Hadlock 1-2 gave the most consistent EFW estimate, with all formulae showing good correlation.

How well do women understand and remember information in labour versus in late pregnancy? A pilot randomised study

Medical informed consent is the process by which a 'competent', non-coerced individual receives sufficient information including risks of a medical procedure and gives permission for it to occur. The capacity to give an informed consent might be impaired during labour. This study aimed to examine women's abilities to understand and remember during labour. Women were prospectively recruited at 36 weeks of gestation and randomised to undertake questionnaires which assessed their ability to understand and remember information. They were randomised to: (1) information given in labour only, written format (2) information in labour, verbal (3) information at 36 weeks plus labour, written (4) information at 36 weeks plus labour, verbal. Immediate comprehension and retention was assessed at 36 weeks, in labour, and 24-72 hours after birth. Forty-nine women completed the questionnaires regarding understanding and retention of information at 36 weeks, six intrapartum, and five postpartum (90% attrition). Women receiving information at 36 weeks and in labour versus in labour had a higher comprehension of pregnancy-related information, its retention, and total score. Women receiving information in late pregnancy and labour may comprehend and retain it better than women only receiving information during labour. Given small sample size, further research is needed to support these preliminary findings. Impact statement What is already known on this subject? The evidence regarding the capacity of labouring women to give informed consent is largely based on women's self-reported experiences or expert opinions and has mixed findings. Existing guidelines recommend that an informed consent should be given antenatally for both clinical practice and research. Studies show that obtaining an informed consent antenatally is neither feasible nor widely implemented. What do the results of this study add? A novel approach to providing empirical evidence regarding women's capacity to comprehend and retain information during labour. Our study confirms the difficulty with antenatal recruitment for intrapartum research. What are the implications of these findings for clinical practice and/further research? This raises ethical concerns regarding the current intrapartum research in which consent is largely sought at the time of the study. Emphasises the need to explore the question 'Do labouring women have the capacity to consent to research?' in order to ensure that women are protected during labour.

Automated Visualization and Quantification of Spiral Artery Blood Flow Entering the First-Trimester Placenta, Using 3-D Power Doppler Ultrasound

The goal of our research was to quantify the placental vascularity in 3-D at 11-13 + 6 wk of pregnancy at precise distances from the utero-placental interface (UPI) using 3-D power Doppler ultrasound. With this automated image analysis technique, differences in vascularity between normal and pathologic pregnancies may be observed. The algorithm was validated using a computer-generated image phantom and applied retrospectively in 143 patients. The following features from the PD data were recorded: The number of spiral artery jets into the inter-villous space, total geometric and PD area. These were automatically measured at discrete millimeter distances from the UPI. Differences in features were compared with pregnancy outcomes: Pre-eclamptic versus normal, all small-for-gestational age (SGA) to appropriate-for-gestational age (AGA) patients and AGA versus SGA in normotensives (Mann-Whitney). The Benjamini-Hochberg procedure was used (false discovery rate 10%) for multiple comparison testing. Features decreased with increasing distance from the UPI (Kruskal-Wallis test; p <0.001). At 2- 3 mm from the UPI, all features were smaller in pre-eclamptic compared with normal patients and for some in SGA compared with AGA patients (p <0.05). For AGA versus SGA in normotensive patients, no significant differences were found. Number of jets measured at 2-5 mm from the UPI did not vary because of the position of the placenta in the uterus (ANOVA; p > 0.05). This method provides a new in-vivo imaging tool for examining spiral artery development through pregnancy. Size and number of entrances of blood flow into the UPI could potentially be used to identify high-risk pregnancies and may provide a new imaging biomarker for placental insufficiency.

Fetal myocardial performance index in assessment and management of small-for-gestational-age fetus: a cohort and nested case-control study

OBJECTIVE

To assess the clinical utility of the fetal myocardial performance index (MPI) in assessment and management of the small-for-gestational-age (SGA) fetus/growth-restricted fetus (FGR).

METHODS

This was a prospective cohort study in metropolitan Australia of patients referred in the period June 2012 to March 2015 to fetal medicine services at 24-38 weeks' gestation for suspected singleton SGA/FGR (estimated fetal weight (EFW) < 10^th centile with or without abnormal umbilical artery (UA) Doppler) pregnancy. Patients had MPI assessed in addition to routine measures, and were followed through to birth. We compared MPI values against those of a local reference population and gestational age-matched controls, and assessed the correlation with perinatal outcome and other Doppler measures.

RESULTS

Fifty-two cases were included, 38 diagnosed < 32 weeks and 14 diagnosed ≥ 32 weeks. None demonstrated significantly elevated left, right or delta MPI compared with the reference population or with gestational age-matched controls at the time of first MPI evaluation. There were no consistent longitudinal patterns in MPI that would suggest its clinical utility. The mean ± SD gestational age at delivery was 34.6 ± 3.8 weeks and birth weight was 1.7 ± 0.6 kg, and the median neonatal hospital admission time was 27 days, confirming a pathological cohort. There were no significant correlations between left, right or delta-MPI and perinatal outcome, although there were significant correlations between UA, middle cerebral artery (MCA) and ductus venosus (DV) Doppler and perinatal outcome (birth weight, gestational age at birth and length of neonatal hospital stay). Exploratory subgroup comparisons (EFW < 3^rd vs 3^rd -10^th centile; early- vs late-onset; abnormal vs normal UA Doppler) found only minor differences in MPI, reaching statistical, but not clinical, significance, only in the EFW < 3^rd vs 3^rd -10^th centile comparison.

CONCLUSIONS

MPI did not demonstrate clinical utility in either triage or longitudinal follow-up of an SGA/FGR cohort presenting to fetal medicine services. Given that prior research suggesting its utility originates from single-center cohorts, while multicenter, large cohorts have suggested little utility or no additional utility if routine UA/MCA/DV Doppler is performed, publication bias may have affected previous reports. It seems unlikely that MPI has clinical utility in assessment and management of SGA/FGR fetuses. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Beat-to-beat variability of fetal myocardial performance index

OBJECTIVES

To determine whether there is beat-to-beat (BTB) variability in the fetal left myocardial performance index (MPI), as evaluated by an automated system, and whether there is a correlation between MPI and fetal heart rate (FHR).

METHODS

This was a prospective cross-sectional study of uncomplicated, morphologically normal, singleton pregnancies at 20-38 weeks' gestation. Multiple cineloops for left MPI measurement were acquired during a single examination of each fetus. Raw cineloop data were analyzed by our automated MPI system (intraclass correlation coefficient of 1.0 for any given waveform) to produce a set of MPIs. The corresponding instantaneous FHR was measured for each individual cardiac cycle for which MPI was calculated.

RESULTS

Data from 29 fetuses were analyzed; mean MPI was 0.52, mean FHR was 150 beats per min and the median number of cardiac cycles examined per fetus was 70 (interquartile range, 31-115). Marked BTB variability was noted; median coefficient of variation was 10% (range, 5.5-13.9%). FHR was weakly correlated with absolute MPI (r = 0.22; P < 0.05). BTB variation in MPI as a percentage of the mean MPI was not significantly correlated with FHR (r = 0.031; P = 0.146). When standard error of the mean of all MPI values was divided by the mean for each case, it showed that at least four cardiac cycles should be averaged to reduce MPI variability to approximately ± 5%.

CONCLUSION

There is significant BTB variability in fetal left MPI, which has an overall weak correlation with FHR. This could be a factor affecting the consistency of MPI values reported by different research groups. Variability would be reduced by averaging 4-5 cardiac cycles per fetus. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

3D fractional moving blood volume (3D-FMBV) demonstrates decreased first trimester placental vascularity in pre-eclampsia but not the term, small for gestation age baby

OBJECTIVE

To undertake an observational study to see whether first trimester placental vascularity, measured with a standardized power Doppler index: 3D-FMBV, is different in pregnancies which either develop pre-eclampsia or lead to term, normotensive small for gestational age (SGA) babies.

METHODS

Women were scanned between 11 and 13+6 weeks. The placental volume (sPlaV) was estimated using our previously validated semi-automated tool. Estimates of 3D-FMBV were generated from the raw power Doppler signal for the whole utero-placental interface, UPI (FMBV-UPI) and 5mm into the placenta (FMBV-IVS). Differences in the placental volume and FMBV for pregnancies developing pre-eclampsia and resulting in term, normotensive SGA babies were compared with term, normotensive, appropriate for gestational age (AGA), controls.

RESULTS

Results were available for 143 women. The placental volume (sPlaV) was reduced in both pre-eclampsia (p = 0.007) and term, normotensive SGA (p = 0.001) when compared with term normotensive AGA controls. 3D-FMBV estimates were significantly lower for pregnancies developing pre-eclampsia (FMBV-UPI, p = 0.03, FMBV-IVS, p = 0.01) but not for the normotensive SGA pregnancies (FMBV-UPI, p = 0.16, FMBV-IVS, p = 0.27).

CONCLUSION

Pregnancies destined to develop pre-eclampsia are more likely to have small placentas with significantly reduced vascularity at 11-13 weeks. Those pregnancies which were normotensive throughout but resulted in an SGA baby delivered at term, had significantly smaller placentas but with similar vascularity to normotensive AGA pregnancies.

Evaluation of an automated fetal myocardial performance index

OBJECTIVE

To compare automated measurements of the fetal left myocardial performance index (MPI) with manual measurements for absolute value, repeatability and waveform acceptability.

METHODS

This was a multicenter international online study using images from uncomplicated, morphologically normal singleton pregnancies (16-38 weeks' gestation). Single Doppler ultrasound cardiac cycle images of 25 cases were selected, triplicated and randomized (n = 75). Six senior observers, unaware of the repetition of images, manually calculated MPI for each waveform and the results were compared with automation. Intraobserver repeatability and interobserver reproducibility were assessed using intraclass correlation coefficients (ICCs) and 95% CI. The agreement between each observer's manual MPI measurements and corresponding automated measurements was evaluated using Bland-Altman plots and ICCs with 95% CI. The degree of variation between experts in the classification of fetal MPI waveform quality was assessed using individual cardiac cycle left MPI images previously classified by two authors as 'optimal', 'suboptimal' or 'unacceptable', with 30 images selected for each quality group. Ten images in each category were duplicated and the resulting 120 images were randomized and then classified online by five observers. The kappa statistic (κ) was used to demonstrate interobserver and intraobserver agreement and agreement of classifications by the five observers.

RESULTS

The automated measurement software returned the same value for any given image, resulting in an ICC of 1.00. Manual measurements had intraobserver repeatability ICC values ranging from 0.69 to 0.97, and the interobserver reproducibility ICC was 0.78. Comparison of automated vs manual MPI absolute measurements for each observer gave ICCs ranging from 0.77 to 0.96. Interobserver image quality classification agreement gave k = 0.69 (P < 0.001), and the intraobserver agreement was variable (κ ranging from 0.40 to 0.81).

CONCLUSIONS

Automated fetal MPI provides superior repeatability and reproducibility to manual methodology. Additionally, experts vary significantly when classifying suitability of fetal MPI waveforms. Automated MPI may facilitate clinical translation by removing human subjectivity. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Uncommon complications of monochorionic twin pregnancies: Twin reversed arterial perfusion sequence

Introduction

Twin reversed arterial perfusion (TRAP) sequence occurs when there is one non-viable twin without cardiac structures and a viable pump twin that perfuses the acardiac mass. This study aims to investigate the management and immediate neonatal outcomes for monochorionic multiple pregnancies complicated by TRAP referred to the NSW Fetal Therapy Centre (NSW FTC).

Methods

Retrospective cohort study of multiple pregnancies referred to NSW FTC between April 2006 and April 2014, reviewing data for cases of TRAP sequence (n = 19, including two triplet cases) compared to a timeframe matched sample of uncomplicated monochorionic diamniotic (MCDA) twin pregnancies managed in the unit (n = 45).

Results

Primary management of the 19 TRAP cases was expectant management in 10 (53%), radiofrequency ablation (RFA) in 6 (32%), and bipolar cord coagulation, amniodrainage and termination of pregnancy in 1 case each. 1 of 6 RFA cases had pump twin demise <1 week post-procedure. Average gestation at birth (35.1 ± 5.0 vs. 35.0 ± 2.8 weeks) and mean birthweight (2157 ± 1019 g vs. 2245 ± 537 g) were similar between TRAP pump fetuses and uncomplicated MCDA cases. Pump twin survival was 81% (twins only) compared to 98% for uncomplicated MCDA twins (P = 0.02), and in 5 of 19 (26%) TRAP pregnancies the pump fetus had a congenital anomaly.

Conclusion

Mean gestational age at birth and mean birthweight were similar for both TRAP and uncomplicated MCDA pregnancies. TRAP cases, however, had higher perinatal mortality, and high rates of congenital anomaly. The overall neonatal outcome at NSW FTC for TRAP cases is similar to reported international outcomes.

The Aortic Isthmus: A Significant yet Underexplored Watershed of the Fetal Circulation

The aortic isthmus (AoI) is a unique fetal watershed with a waveform reflecting its complex haemodynamic physiology. The systolic component represents left and right ventricular systolic ejection, and the diastolic component represents comparative downstream vascular impedance between the brachiocephalic and subdiaphragmatic fetal circulations. Several indices have been devised to quantify different components of the waveform, including the pulsatility index, resistance index, isthmic flow index, and recently the isthmic systolic index. There have been promising preliminary studies applying these indices to both cardiac (congenital) and extracardiac pathologies, including intrauterine growth restriction and twin-twin transfusion syndrome. However, the waveform's multifactorial origin has proven to be challenging, and the difficulty in separating various components of the waveform could explain that AoI evaluation does not have a clear clinical utility. Further research is underway to realise the full potential of this vessel in fetal cardiac and haemodynamically compromised pathological conditions. In this review article we outline the physiological origin of this Doppler waveform, describe in detail the various published indices, summarise the published literature to date, and finally outline potential future research and hopefully clinical applications.

Uncommon complications of monochorionic twin pregnancies: Twin anaemia-polycythaemia sequence

Introduction

Twin anaemia-polycythaemia sequence (TAPS) occurs when significant haemoglobin discordance exists between monochorionic fetuses. Most reported cases occur iatrogenically after twin-to-twin transfusion syndrome (TTTS) laser therapy; spontaneous TAPS is also reported. The purpose of this study was to investigate pregnancy management and immediate neonatal outcomes for monochorionic multiple pregnancies complicated by TAPS referred to the NSW Fetal Therapy Centre (FTC).

Methods

Retrospective cohort study of multiple pregnancies referred to NSW FTC between April 2006 and April 2014. Fourteen TAPS cases [discordant middle cerebral artery peak systolic volume (MCA-PSV) or clinician diagnosis antenatally, or Hb >20 g/dL vs. <12 g/dL post-natally] were compared to an existing TTTS database (n = 142) and uncomplicated monochorionic diamniotic (MCDA) twin pregnancies (n = 45). Outcomes measured were maternal demographics; ultrasound findings at referral; management, including whether in utero fetal therapy was performed; and pregnancy outcome, including gestation at birth, mode of birth, birthweight, fetal/neonatal complications and neonatal survival to discharge.

Results

The majority of TAPS cases were spontaneous (9/14) and occurred later in pregnancy than TTTS (median gestation at diagnosis 26.0 ± 4.9 vs. 20.4 ± 2.6 weeks, P < 0.001). However, TAPS perinatal outcome was similar to TTTS (survival of both twins 62% vs. 53%, survival of at least one twin 85% vs. 87%, overall survival 73% vs. 70%) and overall survival significantly lower than for uncomplicated MCDA pregnancies (73% vs. 98%, P < 0.001).

Conclusion

Overall mortality for TAPS was similar to that of TTTS but significantly higher compared to uncomplicated MCDA pregnancies, underscoring the potential severity of TAPS despite its later gestational onset.

Review of the correlation between blood flow velocity and polycythemia in the fetus, neonate and adult: appropriate diagnostic levels need to be determined for twin anemia-polycythemia sequence

Twin anemia-polycythemia sequence (TAPS) is recognized increasingly antenatally by the demonstration of an anemic twin and a polycythemic cotwin using the middle cerebral artery peak systolic velocity (MCA-PSV). While the MCA-PSV has been shown to correlate well with anemia in singleton fetuses, the evidence to support its use to diagnose fetal polycythemia appears to be less clear-cut. We aimed to evaluate fetal, neonatal and adult literature used to support the use of MCA-PSV for the diagnosis of polycythemia. Comprehensive literature searches were performed for ultrasound evidence of polycythemia in the human fetus, neonate and adult using key search terms. Only manuscripts in the English language with an abstract were considered for the review, performed in June 2014. Fifteen manuscripts were found for the human fetus, including 38 cases of TAPS. Nine of these defined fetal polycythemia as MCA-PSV < 0.8 multiples of the median (MoM), five used < 1.0 MoM and one used 0.8-1.0 MoM. Only two studies, involving a total of 15 cases, proposed a diagnostic level, acknowledging false-positive and -negative cases, though neither reported sensitivities or specificities. Six neonatal studies (96 neonates) demonstrated evidence of decreased cerebral velocities in polycythemia and a consequent increase with hemodilution. In the adult, five studies (57 polycythemic adults) demonstrated increased flow or velocity with hemodilution. Neither neonatal nor adult studies conclusively defined levels for screening for polycythemia. Despite widespread adoption of a cut-off of < 0.8 MoM in the published literature for the polycythemic fetus in TAPS, this is based upon minimal evidence, with unknown sensitivity and specificity. We recommend caution in excluding TAPS based purely upon the absence of a reduced MCA-PSV.

Automated cardiac time interval measurement for Modified Myocardial Performance Index calculation of right ventricle

The Modified Myocardial Performance Index (Mod-MPI) has sparked great interest as a parameter for fetal cardiac function assessment. However, measurement of this index requires expertise and its clinical application might be limited, owing to its poor repeatability. Research groups have been investigating left Mod-MPI (that is, Mod-MPI from left ventricle valve events), and an automated algorithm has been developed for left Mod-MPI calculation in our previous study. Right MPI is also important as it becomes abnormal earlier than left MPI in some pathologies; however, for use across the gestational age spectrum, it requires two-image acquisition. This paper presents an automated method to detect valve movements during atrioventricular outflow and ventricular inflow and to further calculate the time intervals required for right MPI calculation. Ninety pulsed-wave Doppler ultrasound images of the right ventricle in fetuses, forty-five showing outflow and forty-five inflow, were analyzed to automatically detect the valve clicks generated by tricuspid valve movement in inflow waves, and pulmonary valve movement in outflow waves. The morphological characteristics of waves were combined with intensity information to locate clicks. This automated method can detect valve movement events with a high positive predictive value (96.20-98.96%) and sensitivity (97.95-100.00%), using manual annotation from an expert ultrasonographer as the gold standard for evaluation.

Ultrasound (in)accuracy: it's in the formulae not in the technique - assessment of accuracy of abdominal circumference measurement in term pregnancies

Introduction: Fetal abdominal circumference (AC) is utilised in calculations for the estimation of fetal weight (EFW) and has been proposed as a method of monitoring diabetic pregnancies. We evaluated true ultrasound accuracy by comparing fetal AC biometry with neonatal anthropometry and compared this with standard ultrasound estimations of fetal weight.

Methods: A prospective observational study was performed at a tertiary referral centre. Women who were having their confinement of a term, singleton gestation either by induction of labour or elective caesarean section from 2009–2011 were approached to participate. An ultrasound was performed within 24 hours of delivery measuring the biometric parameters of AC, head circumference (HC), biparietal diameter and femur length. Following delivery the AC, HC and birthweight were measured on the neonate.

Results: Fifty‐two patients were enrolled in the study with data collected from 50. Mean AC measurement was 35.1 ± 2.1 cm and birth weight was 3596 ± 517 g. A Bland‐Altman plot was used to compare the two AC measurements with the 95% limits of agreement ranging from −2.33–4.69 cm around a mean difference of 1.2 cm. Mean percentage error was 5.0% and 6.2% for the AC and HC measurements respectively, in comparison with percentage errors of 7.0–13.8% for estimation of fetal weight (EFW) from 27 formulae.

Conclusions: Sonographic AC measurement is accurate in term pregnancies, with a percentage error less than HC or EFW. Perceptions of ultrasound inaccuracy may relate to the application of formulae rather than the ultrasound technique itself. Fetal surveillance using serial AC measurement has been proposed, in particular monitoring of diabetic pregnancies and in such a group AC may be easier and faster to obtain and more meaningful than EFW.

Importance of Pulse Repetition Frequency Adjustment for 3- and 4-Dimensional Power Doppler Quantification

OBJECTIVES

To determine the influence of the pulse repetition frequency (PRF) and wall motion filter on the 3-dimensional (3D) power Doppler vascularization-flow index (VFI) and volumetric pulsatility index (PI) obtained from spatiotemporal image correlation (STIC) data sets acquired from a common carotid artery of a healthy participant.

METHODS

We acquired 11 STIC data sets, 1 for each PRF value ranging from 0.6 to 9.0 kHz. Vascularization-flow index and volumetric PI values were determined from the 440 static 3D data sets contained in these STIC data sets. Additionally, 3 sets of radio-frequency data were acquired for offline processing of different wall motion filter values for PRF values of 0.6, 3.3, and 10 kHz.

RESULTS

We constructed VFI curves and observed 2 patterns: a flattened pattern with a low PRF and a triphasic pattern with a high PRF, correlating with the known pulsed wave Doppler profile of this vessel. Volumetric PI values were around 0 for low PRF settings and increased with increasing PRF. Analysis of the radiofrequency data showed that increasing wall motion filter values gradually filtered out the low-velocity power Doppler signals while retaining the higher-velocity ones, allowing the distinction of integrated power Doppler signal velocity throughout the cardiac cycle.

CONCLUSIONS

We conclude that the PRF and wall motion filter dramatically influence 3D power Doppler indices and the volumetric PI, and the use of PRF values in which minimum VFI values are measured during the diastolic phase in the spectral Doppler wave may validate the use of the volumetric PI.

Monitoring intrahepatic cholestasis of pregnancy using the fetal myocardial performance index: a cohort study

OBJECTIVE

To investigate use of the fetal myocardial performance index (MPI) in assessing intrahepatic cholestasis of pregnancy (ICP).

METHODS

This was a cohort study including cross-sectional and longitudinal data from 31 women with ICP recruited from June 2012 to March 2014. Fetal left, right and delta MPI (LMPI, RMPI and DMPI), and routine measures of fetal growth and wellbeing, were obtained at each ultrasound examination. Results were evaluated with respect to gestational age (GA)-adjusted reference intervals, level of maternal serum bile acid (SBA) and fetal outcome. Lower SBA (≥ 7.5 and < 40 μmol/L) and high SBA (≥ 40 μmol/L) subgroups of cases were defined for the analysis.

RESULTS

A total of 51 ultrasound examinations were performed in 33 fetuses. The mean LMPI, and means of its isovolumetric relaxation time (IRT) and isovolumetric contraction time (ICT) components were significantly higher in all subgroups of cases of ICP relative to the normal reference mean. Considering only the first examination in each case of ICP, IRT was significantly more prolonged in the high SBA group (n = 10) in comparison to the lower SBA group (n = 23) (52.7 ± 8.0 ms vs 47.3 ± 4.8 ms, P = 0.02), and both IRT (r = 0.538, P = 0.001) and LMPI (r = 0.367, P = 0.036) were significantly correlated with SBA concentration. The proportion of high SBA cases with LMPI, RMPI or DMPI > 2 SD above the GA-adjusted reference mean was not significantly greater than for the lower SBA group. On analysis of all data from those cases with more than one examination, no significant correlation was found between SBA concentration and any of the MPI variables.

CONCLUSIONS

LMPI values increase above the population GA-adjusted mean in cases of ICP, particularly amongst women with higher SBA. A significant correlation between IRT and LMPI at initial examination and increasing SBA concentration was found. A future multicenter prospective study may clarify the prognostic utility of MPI in ICP.

Pregnancy outcomes before and after institution of a specialised twins clinic: a retrospective cohort study

BACKGROUND

Although specialised clinics for multiple pregnancies are recommended by several Obstetrics and Gynaecology governing bodies, studies examining outcome before and after introduction of such clinics remain few, were performed predominantly in North America in the 1990s, and either amongst dichorionic twin pregnancies only or where chorionicity was not specified. Our objective, in the modern setting with twins of known chorionicity, was to compare maternal and neonatal outcomes of twin pregnancies before and after commencement of a consultant-led, multidisciplinary twins clinic (TC).

METHODS

Retrospective cohort study of 513 women, with birth of twins at ≥20 weeks' gestation, January 2007 to November 2011, at a metropolitan tertiary maternity hospital, Sydney, Australia. Demographic, pregnancy, and outcome data were obtained from hospital databases. Women receiving TC care (2009-2011) were compared to those receiving general antenatal clinic (ANC) care (2007-2010) and private care (2009-2011). Other models of care were excluded. Main outcome measures were total maternal inpatient stay, mode of birth, gestational age at birth, and neonatal nursery admission.

RESULTS

286 women were included in the main analyses: 84 attended ANC, 101 TC, and 101 a private obstetrician. TC women had similar demographics to ANC women and were slightly younger than private patients. TC women had lower Caesarean section rates (55% vs. 70% ANC and 76% private, p = 0.008) and fewer late preterm (34 + 0-36 + 6 weeks) births, (26%TC vs. 44% ANC and 41% private, p < 0.001). Median maternal inpatient stay was shorter in TC than ANC (7 vs. 8 days, p = 0.009) and similar to private (7 days). Nursery admission rates were higher in private patients (67% vs. 49% ANC and 47% TC, p = 0.001) and average birthweight lower (2283 g vs. 2501 g ANC and 2496 g TC, p < 0.001).

CONCLUSIONS

Within a single centre, maternal and neonatal twin pregnancy outcomes varied significantly by model of care. Introducing a specialised twins clinic in our setting decreased Caesarean section rates, late preterm birth, and inpatient stay compared to ANC.

Why such differing stances? A review of position statements on home birth from professional colleges

Despite low rates of home birth throughout most Western countries, the topic generates considerable debate. This is reflected by the differing positions on home birth adopted by professional colleges representing obstetricians and midwives. We reviewed position statements of midwifery and obstetric colleges in the UK, USA, Australia, New Zealand, and Canada to explore how the same body of research evidence leads to different positions. Aside from a joint statement from the UK we found widely differing stances, reflecting traditional midwifery perspectives of birth as a physiological process versus obstetric perspectives of potential pathology. We feel the differences in position statements are largely the end product of significant confirmatory bias.

TWEETABLE ABSTRACT

Review of organisational position on home birth suggests bias in literature interpretation.

The Fetal Modified Myocardial Performance Index: Is Automation the Future?

The fetal modified myocardial performance index (Mod-MPI) is a noninvasive, pulsed-wave Doppler-derived measure of global myocardial function. This review assesses the progress in technical refinements of its measurement and the potential for automation to be the crucial next step. The Mod-MPI is a ratio of isovolumetric to ejection time cardiac time intervals, and the potential for the left ventricular Mod-MPI as a tool to clinically assess fetal cardiac function is well-established. However, there are wide variations in published reference ranges, as (1) a standardised method of selecting cardiac time intervals used in Mod-MPI calculation has not been established; (2) cardiac time interval measurement currently requires manual, inherently subjective placement of callipers on Doppler ultrasound waveforms; and (3) ultrasound machine settings and ultrasound system type have been found to affect Mod-MPI measurement. Collectively these factors create potential for significant inter- and intraobserver measurement variability. Automated measurement of the Mod-MPI may be the next key development which propels the Mod-MPI into routine clinical use. A novel automated system of Mod-MPI measurement is briefly presented and its implications for the future of the Mod-MPI in fetal cardiology are discussed.

Is There a Measurable Difference between the Left and Right Modified Myocardial Performance Indices, and Does This Change to Reflect Unilateral Myocardial Dysfunction in Pathology?

Introduction: Fetal cardiac dysfunction may manifest itself unilaterally as right and left ventricles differing in design, function and load, measurable as differing in myocardial performance indices (MPIs). We wished to define this difference (‘delta-MPI' or DMPI), present its normal range and pilot its use in pathological pregnancy. Material and Methods: Prospective cross-sectional study of 324 normal singleton fetuses (16-38 weeks of gestation). Left and right modified MPI (LMPI and RMPI) were performed during a single examination using the ‘peak' valve click technique. Thirty-seven pathological singleton and monochorionic diamniotic twin pregnancies were compared as pilot data. Results: Modified MPIs (mean ± SD) were 0.45 ± 0.06 (LMPI) and 0.47 ± 0.09 (RMPI), being similar at 18 weeks' gestation with DMPI increasing slightly throughout pregnancy (0.02 ± 0.08). Both singleton intrauterine growth restriction (IUGR) and recipient twin-twin transfusion syndrome (TTTS) showed significantly elevated RMPI, LMPI and DMPI, most pronounced for DMPI (450 and 500% increase, respectively; p < 0.01). DMPI acquisition rates were 83.3% normal and 87.0% pathological. Discussion: We demonstrate for the first time differing intrafetal LMPI and RMPI in a large gestational cohort, with this difference increasing with gestational age. Pilot data confirm the potential for DMPI as a tool to assess unilateral myocardial function in singleton IUGR and recipient twins in TTTS, and further studies are under way to evaluate its clinical utility.

The (Pulsed-Wave) Doppler Fetal Myocardial Performance Index: Technical Challenges, Clinical Applications and Future Research

Functional cardiovascular assessment is becoming an increasingly important tool in the study of fetal pathology. The myocardial performance index (MPI) is a parameter measuring global myocardial function. Since its introduction, several studies have proposed methods to improve its reproducibility and have constructed normative reference ranges. Fetal heart evaluation using the MPI is technically challenging, requiring specific training and expertise, and a consensus has yet to be reached on the method of delineating the time periods used to calculate the index. Despite these limitations, it has been shown to be a useful and highly sensitive parameter of dysfunction in a number of fetal pathologies. Further research is warranted into the effect of pathology on MPI, parameters of unilateral cardiac strain that utilise MPI, and automation of the MPI to encourage incorporation of the MPI as a useful tool in clinical practice.

Automated fetal cardiac valve movement detection for modified myocardial performance index calculation

The Modified Myocardial Performance Index (Mod-MPI) is becoming an important index in fetal cardiac function evaluation. However, the current method for Mod-MPI calculation can be time-consuming and demonstrates poor inter-operator repeatability. This paper presents an automated method for detecting the opening and closing events of fetal cardiac valves with the aim of automating the Mod-MPI calculation. Fifty-four Doppler ultrasound images, showing blood inflow and outflow for the left ventricle, are analyzed to attempt to automatically detect the timings of a total of 905 opening and closing events for both aortic and mitral valves. Timings are found according to the morphological characteristics of waveforms as well as intensity information of images. The proposed method can detect the four valve movement events with high sensitivity (95.60-98.64%) and precision (96.85-100.00%). Results are verified by comparison with manual annotation of same images from an expert.

Long term developmental outcomes of pre-school age children following laser surgery for twin-to-twin transfusion syndrome

BACKGROUND

Laser therapy is now a well recognised treatment for twin-to-twin transfusion syndrome (TTTS). We investigated the early childhood neurodevelopmental outcome of children post laser treatment for TTTS in our centre.

METHODS

Children of women who had laser therapy for TTTS between March 2006 and June 2008 were assessed at 30-69 months of age with WPPSI-III and a general health questionnaire. Major neurodevelopmental impairment (NDI) was reported as IQ<70 or cerebral palsy (CP). Borderline cognitive impairment was defined by IQ 70-79.

RESULTS

Amongst the 37 pregnancies treated, 62 infants were discharged home and the overall foetal survival rate was 84%. A total of 50 children (84%) from 31 pregnancies were assessed. Average age at assessment was 47 months. Two children with late treatment of congenital hypothyroidism were excluded. The majority of pregnancies were Quintero Stage III (74%). There was a significant trend for worse outcome with higher Quintero stage. The average gestational age at birth was 32 weeks. The majority (39, 78%) of children were found to be neurodevelopmentally normal; 9 (18%) had borderline cognitive development; and 2 (4%) had a major NDI, including one with cerebral palsy (2%).

CONCLUSIONS

There was a modest level of neurocognitive impairment post laser therapy for TTTS, mainly borderline cognitive development, lesser so major NDI. There was a low incidence of cerebral palsy. Routine developmental and neurological follow-up of these children is recommended.

A technique for the estimation of fractional moving blood volume by using three-dimensional power Doppler US

PURPOSE

To (a) demonstrate an image-processing method that can automatically measure the power Doppler signal in a three-dimensional ( 3D three-dimensional ) ultrasonographic (US) volume by using the location of organs within the image and (b) compare 3D three-dimensional fractional moving blood volume ( FMBV fractional moving blood volume ) results with commonly used, unstandardized measures of 3D three-dimensional power Doppler by using the human placenta as the organ of interest.

MATERIALS AND METHODS

This is a retrospective study of scans obtained as part of a prospective study of imaging placental biomarkers with US, performed with ethical approval and written informed consent. One hundred forty-three consecutive female patients were examined by using an image-processing technique. Three-dimensional FMBV fractional moving blood volume was measured on the vasculature from the uteroplacental interface to a depth 5 mm into the placenta by using a normalization volume 10 mm outside the uteroplacental interface and compared against the Virtual Organ Computer-aided AnaLysis ( VOCAL Virtual Organ Computer-aided AnaLysis ; GE Healthcare, Milwaukee, Wis) vascularization flow index ( VFI vascularization flow index ). Intra- and interobserver variability was assessed in a subset of 18 volumes. Wilcoxon signed rank test and intraclass correlation coefficients were used to assess measurement repeatability.

RESULTS

The mean 3D three-dimensional FMBV fractional moving blood volume value ± standard deviation was 11.78% ± 9.30 (range, 0.012%-44.16%). Mean VFI vascularization flow index was 2.26 ± 0.96 (range, 0.15-6.06). Linear regression of VFI vascularization flow index versus FMBV fractional moving blood volume produced an R(2) value of 0.211 and was significantly different in distribution (P < .001). Intraclass correlation coefficient analysis showed higher FMBV fractional moving blood volume values than VFI vascularization flow index for intra- and interobserver variability; intraobserver values were 0.95 for FMBV fractional moving blood volume (95% confidence interval [ CI confidence interval ]: 0.90, 0.98) versus 0.899 for VFI vascularization flow index (95% CI confidence interval : 0.78, 0.96), and interobserver values were 0.93 for FMBV fractional moving blood volume (95% CI confidence interval : 0.82, 0.97) versus 0.67 for VFI vascularization flow index (95% CI confidence interval : 0.32, 0.86).

CONCLUSION

The extension of an existing two-dimensional standardized power Doppler measurement into 3D three-dimensional by using an image-processing technique was shown in an in utero placental study. Three-dimensional FMBV fractional moving blood volume and VFI vascularization flow index produced significantly different results. FMBV fractional moving blood volume performed better than VFI vascularization flow index in repeatability studies. Further studies are needed to assess accuracy against a reference standard.

Complicated multiple pregnancy referral, treatment and outcomes at the NSW Fetal Therapy Centre

Objectives: To determine the indications for referral, sonographic workload, diagnoses and outcomes of women with a multiple pregnancy referred to the New South Wales Fetal Therapy Centre (NSW FTC). Methods: Retrospective cohort study of twin and higher order multiple (HOM) pregnancies referred to the NSW FTC at the Royal Hospital for Women (RHW) Department of Maternal Fetal Medicine (MFM), Sydney from January 2007 to December 2009.

Results: There were 176 twin pregnancies (138 monochorionic diamniotic, 29 dichorionic diamniotic and nine monoamniotic), and 26 HOMs referred (23 triplet and three quadruplet pregnancies). Indications for referral were: twin to twin transfusion syndrome (TTTS) 103 women, fetal anomaly 31 women, intrauterine growth restriction (IUGR) 12 women, serial surveillance of twins or HOM 37 women, and fetal reduction of HOM (nine women). In 80.2% the pathological referral diagnosis was confirmed. The average number of ultrasounds was five (range 1–24), with 90 women (45%) receiving invasive therapy. Thirty‐five percent (71) of referrals were from outside Sydney, including eight interstate and 11 overseas referrals. Two‐thirds of out of area referrals were able to return to their referral hospital for birth: 95 women (47%) delivered at RHW.

Conclusion: TTTS was the most common reason for referral, with a high concordance between referral and initial diagnosis. RHW accepted a large number of out of area referrals, in keeping with its role as the NSW FTC. Twin and HOM pregnancy referrals represent a significant workload for the 5 department, with many women also requiring invasive therapy.

Selection of the sub-noise gain level for acquisition of VOCAL data sets: a reliability study

This study was aimed at assessing the intra-observer and inter-observer repeatability of selecting the sub-noise gain (SNG) level when acquiring placental volumes with 3-D power Doppler for analysis using virtual organ computer-aided analysis (VOCAL). Sixty women with uncomplicated singleton pregnancies between 20 and 38 wk of gestation were recruited. Two women were excluded for flash artifact noted during image analysis. Two blinded observers independently adjusted gain to their perceived SNG level before acquiring a static 3-D volume of the placenta at the cord insertion; observers alternated after each acquisition until each had acquired two volumes. A single observer operated the probe at all times. During offline analysis, SNG levels were recorded and VOCAL indices were calculated. SNG exhibited excellent intra-observer and inter-observer reliability. Intra-observer intra-class correlation coefficients (95% confidence intervals) were 0.98 (0.97-0.99) and 0.98 (0.98-0.99) for observers 1 and 2, respectively. The inter-observer intra-class correlation coefficient was 0.96 (0.93-0.98). Despite its perceived inherent subjectivity, the excellent intra-class correlation coefficients obtained in this study support SNG as a promising tool for future research using 3-D power Doppler.

Randomised controlled trials and clinical maternity care: moving on from intention-to-treat and other simplistic analyses of efficacy

BACKGROUND

The obstetrical literature is dominated by Randomised Controlled Trials (RCTs), with the vast majority being analysed using an intention-to-treat (ITT) approach. Whilst this approach may reflect well the consequence of assignment to therapy and hence the 'trialists'perspective', it may fail to address the consequence of actually receiving therapy (the patient's perspective).

DISCUSSION

This review questions the ubiquitous adherence to the ITT approach, and gives examples of where this may have misled the maternity care professions. It gives an overview of techniques to overcome potential deficiencies in result presentation, using method effectiveness models such as 'Per Protocol' (PP) or 'As-Treated' (AT) that may give more accurate clinical meaning to the presentation of obstetrical results. It then proceeds to cover the added benefits, considerations and potential pitfalls of the use of Instrumental Variable (IV) models in order to better reflect the clinical context.

SUMMARY

While ITT may achieve statistical purity, it frequently fails to address the true clinical or patient's perspective. Though more complex and potentially beset by problems of their own, alternative methods of result presentation may better serve the latter aim. Each of the other methods may rely on untestable assumptions and therefore it is wisest that study results are presented in multiple formats to allow for informed reader evaluation.

Inapplicability of fractional moving blood volume technique to standardize Virtual Organ Computer-aided AnaLysis indices for quantified three-dimensional power Doppler

OBJECTIVE

To determine whether the technique of fractional moving blood volume (FMBV) is applicable to Virtual Organ Computer-aided AnaLysis II (VOCAL II™)-based indices to quantify three-dimensional power Doppler ultrasound (3D-PDU) by investigating the effect of gain level on the indices measured at a possible reference point for standardization.

METHODS

Ten women with singleton pregnancy between 33+3 and 37+5 weeks' gestation were recruited. The optimal position for 3D acquisition of cord insertion into the placenta was identified and static 3D-PDU volumes were acquired using consistent machine configurations. Without moving the probe or the participant changing position, successive 3D volumes were stored at -3, -5, -7 and -9 dB and at the individualized sub-noise gain (SNG) level. Volumes were excluded if flash artifact was present, in which case all five volumes were reacquired. Using 4D View software, the cord insertion was magnified and the smallest sphere possible was used to measure vascularization index (VI), flow index (FI) and vascularization flow index (VFI). The associations between VOCAL indices and gain level were assessed using Pearson's correlation coefficient.

RESULTS

VOCAL indices for cord insertion correlated poorly with gain level, whether fundamental or relative to SNG level (R(2) = 0.07 and 0.04, respectively). VI was consistently 100% and mean FI and VFI were 99.5 (SD, 0.57), with all values > 97 irrespective of gain level.

CONCLUSIONS

Whilst previous work has shown that gain correlates well with placental tissue VOCAL indices, the correlation between gain level and VOCAL indices in an area of 100% vascularity at the cord insertion is poor. Regions of 100% vascularity appear to be artificially assigned a value approaching 100% for all VOCAL indices irrespective of gain level. This precludes using the technique of VOCAL indices from large vessels to standardize power Doppler measurements and the FMBV index is therefore not applicable to image analysis using VOCAL.

Collaboration in maternity care is achievable and practical

BACKGROUND

Enhancing collaboration has been highlighted as a marker for future success in maternity care, although this suggestion comes with little methodological guidance. This study assessed the efficacy of a collaborative partnership between obstetric doctors and midwives providing Midwifery Group Practice (MGP) care.

METHODS

A retrospective analysis was undertaken with notes from weekly case review meetings held between the obstetricians and midwives over a 12-month period; audio recordings and a prospective analysis of 16 meetings with verbal contributions of the different professions; the number and types of cases discussed and referred, medical records kept at these meetings and a professional satisfaction questionnaire. Consistency of care was measured against the Australian National Midwifery Guidelines for Consultation and Referral.

RESULTS

Of the 337 women booked with MGP, 50% were discussed at least once. Of these, 35% were referred for consultation with an obstetrician. Women as 'Patients' were most commonly discussed, followed by educational discussions and anecdotes with equal verbal contributions from midwives and doctors. Plans for each case were recorded 97% of the time, and adhered to 90% of the time. A high level of consistency of care between similar cases (75% of the time) and with the consultation and referral guidelines (85% of the time) were achieved. Professional satisfaction with this model of care rated highly for both groups.

CONCLUSION

Inter-professional collaboration between midwifery and obstetric staff is highly attainable within this model of care. This study reinforces the effectiveness of collaboration in the MGP model of care for women of all risk levels and should encourage other maternity care providers to consider adopting this collaborative model.

Spatiotemporal image correlation-derived volumetric Doppler impedance indices from spherical samples of the placenta: intraobserver reliability and correlation with conventional umbilical artery Doppler indices

OBJECTIVE

Volumetric impedance indices derived from spatiotemporal image correlation (STIC) power Doppler ultrasound (PDU) might overcome the influence of machine settings and attenuation. We examined the feasibility of obtaining these indices from spherical samples of anterior placentas in healthy pregnancies, and assessed intraobserver reliability and correlation with conventional umbilical artery (UA) impedance indices.

METHODS

Uncomplicated singleton pregnancies with anterior placenta were included in the study. A single observer evaluated UA pulsatility index (PI), resistance index (RI) and systolic/diastolic ratio (S/D) and acquired three STIC-PDU datasets from the placenta just above the placental cord insertion. Another observer analyzed the STIC-PDU datasets using Virtual Organ Computer-aided AnaLysis (VOCAL) spherical samples from every frame to determine the vascularization index (VI) and vascularization flow index (VFI); maximum, minimum and average values were used to determine the three volumetric impedance indices (vPI, vRI, vS/D). Intraobserver reliability was examined by intraclass correlation coefficients (ICC) and association between volumetric indices from placenta, and UA Doppler indices were assessed by Pearson's correlation coefficient.

RESULTS

A total of 25 pregnant women were evaluated but five were excluded because of artifacts observed during analysis. The reliability of measurement of volumetric indices of both VI and VFI from three STIC-PDU datasets was similar, with all ICCs ≥ 0.78. Pearson's r values showed a weak and non-significant correlation between UA pulsed-wave Doppler indices and their respective volumetric indices from spherical samples of placenta (all r ≥ 0.23). VOCAL indices from specific phases of the cardiac cycle showed good repeatability (ICC ≥ 0.92).

CONCLUSION

Volumetric impedance indices determined from spherical samples of placenta are sufficiently reliable but do not correlate with UA Doppler indices in healthy pregnancies.