(BJOG. 2017;124:929–934) In the United Kingdom, all women are offered labor induction between 40 and 41 weeks gestation with goal of decreasing the risk of stillbirth. However, this risk may occur earlier in women 35 years and older so it may be beneficial to offer labor induction sooner. However, induction at an earlier gestational age might increase the risk of cesarean delivery. Therefore, a multicenter, randomized trial was performed comparing labor induction and expectant management at 39 weeks gestation in women 35 years and older. This current article reports on a cost-utility analysis that was conducted in conjunction with the clinical trial.

( BJOG 2016;123:510–517) Oral carbohydrate intake is known to improve outcomes in patients undergoing general surgery. It is also used by athletes to improve their performance. Labor also involves significant physical activity where pain and stress may have a doubling effect on basal metabolic rate. The practice of many anesthesiologists has been to withhold oral intake for women in labor due to concerns about gastric aspiration. However, in some countries oral intake of fluid and a light diet during labor are being allowed based on some recent research. Numerous randomized controlled trials (RCTs) have been performed over the years to assess if oral carbohydrate supplementation could have a positive impact on labor outcomes. This current systematic review attempted to determine this impact using an individual patient data meta-analysis.

Introduction Accurate diagnosis of disturbance in fetal size is needed to manage pregnancies and ensure optimal outcome. Conventionally ultrasound is used to estimate fetal weight (EFW) but diagnostic accuracy is poor. Methods Fetal MRI was performed on a 1.5 Tesla Philips Achieva scanner. Half Fourier Single Shot Turbo Spin-Echo (HASTE) and Balanced Fast Field Echo (bFFE) sequences of the uterine cavity were acquired. Fetal volume was measured by drawing a freehand mask around the fetus in contiguous slices using Analyse 9.0. To convert estimated fetal volume into MR_EFW the formula MR_EFW = 0.12 +1.031 × fetal_volume (1) was used. MR centiles were then calculated using the GROW customised centile calculator. The diagnostic accuracy of MRI in the detection of large (>90th centile: LGA) and small (<10th centile: SGA) for gestational age fetuses was calculated by comparison with actual birth-weight centiles. Results MRI was performed at an average gestational age of 35+0 weeks (SD ± 7 days) in 37 subjects. The average MR_EFW was 2554 (±437) g with a median MR_centile of 42.8. Mean gestational age at delivery was 39+3 weeks (±11 days) with a mean birth-weight of 3349 (±593) g and median birth-weight centile of 34.0. For LGA MRI had sensitivity: 83.3%, specificity: 96.6%, positive predictive value: 83.3% and negative predictive value: 96.6%. Corresponding values for SGA were 57.1%, 100%, 100%, 90.3%, respectively. For birth-weight <5th centile MRI had a sensitivity and specificity of 100%. Conclusion In this small study the diagnostic accuracy of MRI_EFW is superior to those quoted for USS_EFW (2, 3). References Baker PN, Johnson IR, Gowland PA, Hykin J, Harvey PR, Freeman A, et al. Fetal weight estimation by echo-planar magnetic resonance imaging. Lancet. 1994;343(8898):644–5 Chauhan SP, Cole J, Sanderson M, Magann EF, Scardo JA. Suspicion of intrauterine growth restriction: Use of abdominal circumference alone or estimated fetal weight below 10%. J Matern Fetal Neonatal Med. 2006;19(9):557–62 Coomarasamy A, Connock M, Thornton J, Khan KS. Accuracy of ultrasound biometry in the prediction of macrosomia: a systematic quantitative review. BJOG. 2005;112(11):1461–6

OBJECTIVES:To assess the reliability of magnetic resonance imaging (MRI) to measure fetal fat volume in utero, and to study fetal growth in women with and without diabetes in view of the increased prevalence of macrosomia in the former. METHODS:We studied 26 pregnant women, 14 with pre-gestational diabetes and 12 non-diabetic controls. Fetal assessment took place at 24 weeks' gestation and again at 34 weeks by standard ultrasound biometry followed by MRI at 1.5 T. Fetal fat volume was determined from T1-weighted water-suppressed images using a semi-automated approach based on pixel intensity and taking into account partial volume effects. Fetal volume was also determined from the MRI images. Fetal weight was calculated using published fat and lean tissue densities. RESULTS:There was little fetal fat at 24 weeks' gestation, but at 34 weeks the fetal fat content was considerably higher in the women with diabetes, with a mean fat content of 1090 ± 417 cm(3) compared with 541 ± 348 cm(3) in the controls (P = 0.006). Measurements of fetal fat volume showed low intra- and interobserver variability at 34 weeks, with intraclass correlation coefficients consistently above 0.99. Birth-weight centile correlated with fetal fat volume (R(2)  = 0.496, P < 0.001), percentage of fetal fat (R(2)  = 0.362, P = 0.008) and calculated fetal weight (R(2)  = 0.492, P < 0.001) at 34 weeks. CONCLUSIONS:MRI appears to be a promising tool for the determination of fetal fat, body composition and weight in utero during the third trimester of pregnancy.

AIMS:The reason for the fivefold increased risk of stillbirth in women with diabetes is not known. Further understanding of the underlying mechanisms may facilitate identification of pregnancies at increased risk. We have compared post-mortem reports in matched pairs of stillbirths in women with and without diabetes.METHODS:Post-mortem reports were provided by the Centre for Maternal and Child Enquiries. Stillbirths as a result of lethal congenital and genetic abnormalities were excluded. Whole body, placenta and organ weights and histo-pathological findings in cases and controls were compared and also related to published reference values.RESULTS:We analysed post-mortem reports on 23 matched pairs of stillbirths from 2009 to 2010. Mean placental weight in women with diabetes was 75 g less than in control subjects (95% CI -143 to -7 g; P = 0.032). In maternal diabetes, the thymus was often small and showed a 'starry sky' pattern on histology in 11 of 20 cases compared with four of 22 controls (P = 0.03). This histological finding was associated with a particularly low mean placental weight z-score -2.1 (1.1) standard deviations below a reference population corrected for gestational age.CONCLUSIONS:In over half of the stillbirths occurring in women with diabetes, there was a 'starry sky' appearance in the fetal thymus on histology, this being associated with a small placenta. These findings are consistent with a critical subacute metabolic disturbance being a prominent cause of the increased risk of stillbirth in pregnancies complicated by maternal diabetes.

OBJECTIVES:In maternal diabetes the placenta is large with abnormal vascular development and increased villous volume. We used a novel stereological 3D power Doppler ultrasound technique to investigate differences in-vivo in the placental fractional volume of power Doppler signal (FrVol-PD) between women with and without diabetes. METHODS:We recruited 17 pregnant women with pre-gestational diabetes and 20 controls, all with anterior placentae. Each subject had ultrasound scans (Voluson 730 Expert) every 4 weeks between 12 and 32 weeks gestation. 3D power Doppler data were acquired and the placenta manually outlined using VOCAL (4D View). Power Doppler signal within the resultant volume was counted in a 3D manner adapting the random but systematic techniques used in stereology. RESULTS:Subjects were of similar age, BMI and parity. From 16 weeks the mean (SD) placental FrVol-PD was higher in the non-diabetic than in the diabetic group: 16 weeks - 0.125 (0.03) versus 0.108 (0.03), 20 weeks - 0.144 (0.05) versus 0.104 (0.03), 24 weeks - 0.145 (0.05) versus 0.128 (0.03), 28 weeks - 0.159 (0.05) versus 0.133 (0.02) and 32 weeks - 0.154 (0.03) versus 0.123 (0.04). These differences were significant between control and diabetic subjects [F(1,35) = 4.737, p = 0.036] and across gestation [F(3,140) = 8.294, p < 0.001]. CONCLUSION:Using a novel stereological-based ultrasound technique we have demonstrated the reliability of this application in the placenta. This technique shows promise for non-invasive assessment of placental function: further studies are required to identify if structural changes in a diabetic placenta are accompanied by altered function, manifest as reduced perfusion demonstrable in-vivo.

Objective Maternal diabetes substantially increases the risk of late IUD. A greater understanding of the underlying mechanism might allow identification of pregnancies at increased risk. We have studied post-mortem reports to investigate differences between IUD of fetuses from women with and without diabetes. Methods From the Centre for Maternal and Child Enquiries (CMACE), we obtained post mortem reports of cases of perinatal death in women with and without diabetes. Case pairs were matched for gestational age, birth weight, maternal BMI, deprivation index and ethnicity. We excluded cases/controls with multiple birth, lethal congenital abnormality, and neonatal death. Results Data are presented on 24 pairs; gestational ages ranged from 173 to 280 days and birth weights from 150 to 4650g. In women with diabetes, the mean placental weight was significantly less than in controls (328g vs 399g; p=0.034; 95% confidence interval -135 to -6g) and the gestational age corrected placental weight was 0.81 (SEM 0.41) standard deviations below population reference values (P=0.05). Brain and spleen weights were significantly lower in the infants of diabetic mothers (brain: mean 235 (SEM 25)g vs 274 (27)g; p=0.032; spleen: 3.5 (0.7)g vs 5.5 (1.1)g; p=0.04). There was a trend for the thymus and liver to be lighter and the heart heavier in the fetuses of diabetic mothers. Conclusion In pregnancies in women with diabetes which end in late IUD, the placenta, brain and spleen are lighter than in controls and we postulate placental and organ growth may identify diabetic women at risk of IU.

Introduction Optimal placental blood flow is essential for adequate materno-fetal nutrient exchange and a successful gestation. In maternal diabetes the placenta is often large with abnormal vascular development. To date, it has not been possible to study placental blood flow in detail, but MRI potentially provides such a technique. Aims To compare blood flow within the placenta in diabetic and control pregnancies using MRI. Methods Six women with diabetes and six controls had MRI scans at 24–26 weeks. A 1.5 T Philips Achieva MRI scanner was used. The IVIM sequence was respiratory gated, standard diffusion pulsed spin echo sequence acquired with five transverse slices encompassing the placenta at 12 b values, repeated five times. Analysis was performed to calculate the fractional moving blood volume (f, range 0–1) in each voxel of the entire placenta. Results The mean value of f in the two groups was similar; control (0.37) and diabetic (0.34). The women with diabetes had wider distributions of f with a lower mode (0.26 vs 0.32, p=0.04) and a borderline increased fraction of voxels with very high perfusion (f >0.8) at 4.1% vs 2.5% in controls (p=0.06). Conclusions We have for the first time antenatally demonstrated a difference in the distribution of placental blood flow in women with diabetes using MRI. It is possible that the high velocity blood flow observed in some intervillous spaces is of pathological significance. MRI provides a potentially valuable tool for the investigation of placental blood flow.

To assess the inter-observer reliability of fetal head biometry using archived 3D volumes and the impact of gestational age and presence of brain anomalies on examiners' performance. Seventy nine 3D volume datasets of fetal head were examined. 27 were normal, 52 had abnormalities. Offline analysis was done by 3 fetal medicine experts (E1, E2 &E2), all blinded to history and patient details. Measurements of the biparietal diameter (BPD), head circumference (HC), lateral ventricle (Vp), and transcerebellar diameter (TCD) were compared between examiners and to 2D measurements. Comparisons were made at 2 gestational age groups (⩽ 22 and > 22 weeks) and in presence and absence of anomalies. The intra-class co-efficient showed a high level of measurement agreement between 3D examiners and 2D with values greater than 0.9 throughout. Bias was evident between 3D examiners. E2 produced smaller measurements. The mean percentage difference between this examiner and the other two in BPD, HC, Vp, and TCD measurements was significant, of 1.6%, 1%, 4.9%, and 1.8% respectively. E1 measured statistically larger for HC and TCD with a mean difference of 0.9% and 2.2%. E3 measured significantly larger for only BPD. The presence of ultrasound anomalies was of no influence on the 3D examiners' performance except for E3 who showed bias in BPD measurements only in cases with brain anomalies. Unlike other examiners, bias of E2 was only seen at gestational age group ⩽ 22 wk. Despite this bias the actual mean difference between examiners was small and unlikely to be of any clinical significance. Measurements by E2 were 2 mm less for HC and 1 mm less for other parameters. Offline measurement of fetal head biometry using 3D volume dataset is reliable. In our study presence of brain anomalies was unlikely to influence the reproducibility of measurements. Gestational age seemed to be of an impact on examiners' bias. Among experts this bias may be of no clinical significance.

Optimal placental blood flow is essential for materno-fetal nutrient exchange. Aberrant placental perfusion is associated with growth restriction and pre-eclampsia. Placental vascularity varies from the placental centre to periphery, as histologically, increased spiral artery remodelling is evident in the centre. This has not been demonstrated in vivo with any imaging technique. MRI permits a larger field of view than ultrasound and has the ability to acquire the whole placenta in a single acquisition. We hypothesised that MRI can be used to objectively quantify placental blood flow. MRI (1.5 T Philips Achieva) was performed at 24–26 weeks and at 34–36 weeks in 5 women. A respiratory-gated, standard diffusion, pulsed-spin echo sequence was used to acquire 5 transverse slices including the whole placenta and repeated 5 times. A region of interest was drawn around the whole placenta and the fractional moving blood volume (f) was calculated using the IVIM equation in Matlab. The central slice was defined independently by 2 observers. A single observer traced all 5 slices of each placenta. The intra-observer ICC of whole placental measurements for both observers, independent of gestation, was > 0.9. Intra-observer limits of agreement for measurements made by observer 1 ranged at ± 17% and observer 2 at ± 18%. Inter-observer ICC for the whole placental measurement, regardless of gestation was > 0.86. Limits of agreement were wider and ranged from − 50% to 60%. The mean f of peripheral slices, independent of gestation, was 0.044 compared to 0.069 for central slices. The ratio of f between the central and peripheral slices increased from 1 : 1 at 24–26 weeks to 1.7 : 1.0 at 34–36 weeks although this change was not significant (P = 0.23). MRI can be used to reliably acquire and quantify the fractional moving blood volume within the placenta. Placental blood flow appears to be higher in the centre of the placenta than at the periphery. MRI has the ability to identify differences in placental perfusion and could be used to quantify pathophysiological processes.

In maternal diabetes the placenta is large with abnormal vascular development and increased villous volume. The aim of this study was to use a novel stereological 3D power Doppler ultrasound technique to investigate differences in-vivo in the fractional volume of placental blood vessels (FrVolBV) between women with and without diabetes. 20 normal women and 17 with pre-gestational diabetes, with anterior placentae were recruited. Subjects were matched for age, BMI and parity. Each subject had scans every 4 weeks between 20 and 32 weeks gestation using a Voluson 730 Expert scanner. The VOCAL tool within 4D View (GE Medical Systems) was used to outline the placenta. The power Doppler signal within this volume was counted in a three-dimensional manner adapting the random but systematic techniques used in stereology. The mean (SD) placental FrVolBV was higher in the non-diabetic than in the diabetic group at each gestation; 0.144 (0.05) versus 0.104 (0.03) at 20 weeks, 0.145 (0.05) versus 0.128 (0.03) at 24 weeks, 0.159 (0.05) versus 0.133 (0.02) at 28 weeks and 0.154 (0.03) versus 0.123 (0.04) at 32 weeks. There was a significant difference in FrVolBV between normal and diabetic subjects [F(1.31) = 5.396, P = 0.027] and across gestation [F(3.93) = 3.633, P = 0.016]. Placental FrVolBV is reduced in women with diabetes from 20 weeks gestation using this novel stereological technique. This contrasts with the known increase in volume of the villous vasculature determined histologically. Structural changes in the large and apparently vascular placenta are therefore accompanied by altered function, with reduced perfusion demonstrable in-vivo.

In maternal diabetes the placenta is large with abnormal vascular development and increased villous volume. A prospective, longitudinal observational study of 3D power Doppler vascular indices was performed to investigate differences in-vivo in placental vascularity between women with and without diabetes. 28 normal women and 20 with pre-gestational diabetes, were recruited. Each subject had 3 scans between 12 and 20 weeks gestation using a Voluson 730 Expert scanner. The VOCAL tool within 4D View (GE Medical Systems) was used to outline the placenta in the A plane using the 9° rotation step. To compensate for depth attenuation the 3D vascular indices were standardised against the FI at the centre of a nearby vessel. Subjects were matched for age, BMI and parity. Mean FI.fmbv was 52.07 ( ± 6.0), 50.48 ( ± 5.1) and 53.83 ( ± 4.6) at 12, 16 and 20 weeks respectively. ANOVA demonstrated a significant difference across gestation for the FI.fmbv [F(1.86, 83.82) = 6.37; P = 0.003] and between groups (P = 0.001). There was no difference across gestation or between groups (VI.fmbv, P = 0.29; VFI.fmbv P = 0.48) for the other two standardised 3D vascular indices. The FI.fmbv was significantly higher in subjects with microalbuminuria but not related to retinopathy, hypertension, diabetes type or duration. Standardised placental FI (FI.fmbv) is increased in women with diabetes between 12 and 20 weeks gestation. Structural changes in the large and apparently vascular placenta are therefore accompanied by altered function, with increased signal intensity but not markers of vessel numbers demonstrable in-vivo.

Aim To assess accuracy and interobserver reproducibility of the offline analysis of the 3D volume datasets in the diagnosis of fetal brain abnormalities. Methods Seventy-nine 3D volume datasets were acquired at the time of scanning for women attending a tertiary centre. They included 52 cases with brain abnormalities and 27 normal cases without any brain abnormalities. Postnatal MRI or postmortem examination confirmed the final diagnosis in all cases with brain anomalies. Offline analysis of the 79 unidentified 3D volume datasets was carried out by three fetal medicine experts (E1, E2 and E2) using 4D view software. Experts were blinded to any prior diagnosis or history. Data were collected on special designed data sheet and entered in a specialised database for analysis. Results were compared between examiners and with final definitive diagnosis. Results 87 anomalies in 52 fetuses were described in the definitive diagnosis. In 88.4% (46/52), 98.1% (51/52) and 92.3% (48/52) of cases these anomalies were correctly diagnosed by E1, E2 and E3 respectively. Cases without brain anomalies were diagnosed by the three experts with agreement of 100%. There was good agreement between 2D and each of the 3D experts; in 86.1% of cases with E1 (k=0.7), 89.9% with E2 (k=0.79) and 88.6% of cases with E3 (k=0.76). Conclusion Offline analysis of 3D datasets is operator dependant. However, it is a reliable method that can be used to help in the assessment of brain anomalies and it could be a useful adjunct to real time 2D ultrasound.

OBJECTIVEThe primary objective was to determine the proportion of babies who acquired passive immunity to A/H1N1v, born to mothers who accepted vaccination as part of the national vaccination programme while pregnant (during the second and/or third trimesters) against the novel A/H1N1v influenza virus (exposed group) compared with unvaccinated (unexposed) mothers.DESIGNAn observational study at three sites in the UK. The purpose was to determine if mothers immunised against A/H1N1v during the pandemic vaccination period transferred that immunity to their child in utero.SETTINGThree sites in the UK [Queen's Medical Centre, Nottingham; City Hospital, Nottingham (both forming University Hospitals Nottingham), and Leicester Royal Infirmary (part of University Hospitals Leicester)].PARTICIPANTSAll pregnant women in the second and third trimester presenting at the NHS hospitals above to deliver were eligible to participate in the study. Women were included regardless of age, social class, ethnicity, gravida and parity status, past and current medical history (including current medications), ethnicity, mode of delivery and pregnancy outcome (live/stillbirth).INTERVENTIONSAt enrolment, participants provided written consent and completed a questionnaire. At parturition, venous cord blood was obtained for serological antibody analysis. Serological analysis was undertaken by the Respiratory Virus Unit (RVU), Health Protection Agency (HPA) Centre for Infections, London.MAIN OUTCOME MEASURESThe primary end point in the study was the serological results of the cord blood samples for immunity to A/H1N1v. Regarding a suitable threshold for the determination of a serological response consistent with clinical protection, this issue is somewhat complex for pandemic influenza. The European Medicines Agency (EMEA) Committee for Human Medicinal Products (CHMP) judges that a haemagglutination inhibition (HI) titre of 1 : 40 is an acceptable threshold. However, this level was set in the context of licensing plain trivalent seasonal vaccine, where a titre of 1 : 40 is but one of several related immunogenicity criteria, and supported by paired sera capable of demonstrating a fourfold rise in antibody titre in response to vaccination. The current study mainly investigated the effects of an AS03-adjuvanted monovalent vaccine, and it was not possible to obtain paired sera where the initial sample was taken before vaccination (in vaccinated subjects). Of possibly greater relevance is the fact that it has been established from the study of early outbreaks of pandemic influenza in secondary schools in the UK (HPA, unpublished observations) that an HI antibody titre of 1 : 32 seems to be the threshold for a humoral response to 'wild-type' A/H1N1v infection. On that basis, a threshold of 1 : 32 is at least as appropriate as one of 1 : 40, especially in unvaccinated individuals. Given the difficulties that would accrue by applying thresholds of 1 : 32 in unvaccinated patients and 1 : 40 in vaccinated patients, we have therefore applied a threshold of 1 : 32 and 1 : 40, to increase the robustness of our findings. Differences arising are described. A microneutralisation (MN) titre of 1 : 40 may be also used, although it is not part of the CHMP criteria for vaccine licensure. Nonetheless, we utilised this analysis as a secondary end point, based on a conservative threshold of 1 : 60.RESULTSReverse cumulative distribution percentage curves for haemagglutinin dilution and MN titres demonstrate background immunity in babies of unvaccinated mothers of 25%-30%. Humoral immunity in babies of vaccinated mothers was present in 80% of the group. The difference in positive immunity between the babies of unvaccinated and vaccinated mothers was statistically significant (chi-squared test, p < 0.001).CONCLUSIONSOur findings reveal a highly significant difference in HI titres between babies born to mothers vaccinated with pandemic-specific vaccine against A/H1N1v during the 2009-10 pandemic period. The subjects recruited were comparable from a baseline perspective and thus do not represent different groups that otherwise could have introduced bias into the study. Continued circulation of 2009 A/H1N1-like viruses is uncertain, but is possible as seasonal influenza in years to come. It is possible that future seasonal waves may display increased virulence. Given the adverse outcomes experienced for a small proportion of pregnant women during the influenza pandemic of 2009-10, this study provides useful evidence to support vaccination in pregnancy to protect both the mother and baby.FUNDINGThe National Institute for Health Research Health Technology Assessment programme.

Aim To assess interobserver reproducibility of the offline measurement of fetal head biometry of the 3D volume datasets and to compare them with measurement taken during the real time 2D scan. Methods 79 3D volume datasets of fetal head were obtained at the time of the scan. 27 were normal, 52 had abnormalities. Offline analysis of them were carried out by three independent fetal medicine experts (E1, E2 and E2) using 4D view software. Measurements of the biparietal diameter (BPD), head circumference (HC), posterior horn of the lateral ventricle (Vp) and transcerebellar diameter (TCD) were compared between examiners and to 2D measurements recorded in patient record. All examiners were blinded to history and patient details. Results The intraclass co-efficient for data analysis demonstrated a high level of measurement reproducibility between 2D and 3D E1, 3D E2 and 3D E3 with values greater than 0.9 throughout. Bland–Altman plots showed good levels of agreement between 2D and all three 3D observers. The mean percentage differences for the prespecified parameters are 0.3%, 0.7%, 1% and 1.1% for BPD, HC, Vp and TCD respectively. Conclusion Offline measurement of fetal head biometry using 3D volume dataset is a reliable and reproducible method and correlates well with real time 2D ultrasound. Further work is required to assess the potential use of offline 3D volume dataset analysis as a teaching aid in the measurement of fetal biometry and to examine brain abnormalities.

3D power Doppler angiography (3DPDA) allows quantification of blood flow within the placenta. This study investigated the reproducibility of 3DPDA data analysis at varying gestations. We hypothesised a high level of agreement for measurements of the same dataset on two occasions by the same observer. Women were scanned at 12, 16 and 20 weeks gestations with a Voluson 730 Expert. 3DPDA sweeps of the entire placenta were captured and analysed using the VOCAL software and 9 degree rotation. Each image was analysed by a single observer twice in the B and C plane. Intraobserver reliability was assessed by two-way mixed intraclass correlation coefficients (ICCs) and Bland–Altman plots were used to estimate the level of agreement between the measurements. 52 low risk women were scanned a between one and three times at 12, 16 and 20 weeks gestation, resulting in 30 subjects at each gestation and 90 datasets in total. The ICC for data analysis suggests a high level of intraobserver agreement at each gestation. Reliability was less in the C plane, for each index at all gestations, which subjectively related to poorer image quality. Reliability was higher for measurements in the B plane and confirmed by narrow limits of agreement between observations. This study demonstrates that, for a single observer, repeated measurements of placental 3D power Doppler data produce similar and reliable results. OC16.04: Table

3D power Doppler angiography (3DPDA) allows quantification of blood flow within a volume. This study investigated the reproducibility of acquisition of 3DPD data from the whole placenta. We hypothesised a high level of agreement for measurements of 2 different datasets of the same placenta acquired and measured by one observer. Subjects were scanned at 12, 16 and 20 weeks gestation with a Voluson 730 Expert. 3DPDA sweeps of the entire placenta were captured and analysed using VOCAL and 9 degrees of rotation. Each image was analysed by one observer twice in the B plane. Reliability of measurements was assessed by two-way mixed intraclass correlation coefficients (ICCs) and Bland–Altman plots estimated the level of agreement between the measurements. 52 low-risk women were recruited. 3DPDA data were available in 30 subjects at each gestation resulting in 90 datasets in total. Mean ICCs for image acquisition were 0.952(0.903–0.977), 0.895 (0.791–0.948) and 0.950 (0.899–0.976) for VI, FI and VFI at 12 weeks suggesting good intraobserver reliability. At 16 (0.802, 0.703 and 0.776) and 20 weeks (0.826, 0.832 and 0.843) values remained high but were lower than at 12 weeks. Bland–Altman plots confirmed a high level of agreement between measurements at all gestations. This study suggests that, for a single observer, 3DPDA can be used to reliably acquire and measure the vasculature of the placenta during the up to 20 weeks. Supporting information can be found in the online version of this abstract. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

3D power Doppler angiography (3DPDA) allows quantification of blood flow within the placenta. The aim of this study was to investigate the interobserver reproducibility of quantitative 3DPDA as a tool to assess placental vascularity. Subjects were scanned at 12, 16 and 20 weeks gestations with a Voluson 730 Expert. 3DPD data were acquired from the whole placenta and analysed using VOCAL and 9 degree rotation steps. Each image was analysed by three observers who made two measurements in the transverse (B) plane. Interobserver reliability was assessed by two-way mixed intraclass correlation coefficients (ICCs) and Bland–Altman plots estimated the level of agreement between the observers. 52 low risk women were scanned at varying gestations resulting in 30 subjects at each gestation and 90 datasets in total. The ICC for data analysis demonstrated a high level of measurement reliability at each gestation: ICC 0.871, 0.968 and 0.980 for VI; 0.911, 0.924 and 0.958 for FI; 0.981, 0.959 and 0.977 for VFI at 12, 16 and 20 weeks gestation. Bland–Altman plots showed a progressive reduction in the agreement between the observers with increasing gestation. This study demonstrates that 3DPDA data can be measured by different observers to produce a quantitative analysis of whole placental vasculature. Measurements become less reliable as gestation advances. Supporting information can be found in the online version of this abstract. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

A. M. Al-Radaideh, V. Kareem, C. Costigan, N. Jones, T. Paus, G. Bugg, and P. A. Gowland Sir Peter Mansfield Magnetic Resonance Centre, The University Of Nottingham, Nottingham, United Kingdom, Brain and Body Centre, The University Of Nottingham, Nottingham, United Kingdom, The University Of Nottingham, Nottingham, United Kingdom, Brain and Body Centre, The University of Nottingham, Nottingham, United Kingdom