The worldwide incidence of placenta accreta spectrum (PAS) is rapidly increasing, following the trend of rising cesarean delivery. PAS is an heterogeneous condition associated with a high maternal morbidity and mortality rate, presenting unique challenges in its diagnosis and management. So far, the rarity of this condition, together with the absence of high quality evidence and the lack of a standardized approach in reporting PAS cases for the ultrasound, clinical, and pathologic diagnosis, represented the main challenges for a deep understanding of this condition. The study of the available management strategies of PAS has been hampered by the heterogeneity of the available epidemiological data on this condition. The aim of this review is to provide a critical view of the current available evidence on the screening, the diagnosis, and the management options for PAS disorders, with a special focus on the challenges we foresee for the near future.

Background: Prenatal diagnosis of coarctation of the aorta (CoA) is still challenging and affected by high rates of false-positive diagnoses. The aim of this study was to ascertain the strength of association and to quantify the diagnostic accuracy of different ultrasound signs in predicting CoA prenatally. Methods: Medline, Embase, CINAHL, and Cochrane databases were searched. Random-effects and hierarchical summary receiver operating characteristic model meta-analyses were used to analyze the data. Results: Seven hundred ninety-four articles were identified, and 12 (922 fetuses at risk for CoA) articles were included. Mean mitral valve diameter z score was lower ( P <0.001) and the mean tricuspid valve diameter z score was higher in fetuses with CoA than in those without CoA ( P =0.01). Mean aortic valve diameter z score was lower in fetuses with CoA than in healthy fetuses ( P ≤0.001), but the ascending aorta diameter, expressed as z score or millimeters, was similar between groups ( P =0.07 and 0.47, respectively). Mean aortic isthmus diameter z scores measured either in sagittal ( P =0.02) or in 3-vessel trachea view ( P <0.001) were lower in fetuses with CoA. Conversely, the mean pulmonary artery diameter z score, the right/left ventricular and pulmonary artery/ascending aorta diameter ratios were higher ( P <0.001, P =0.02, and P =0.02, respectively) in fetuses with CoA in comparison with controls, although aortic isthmus/arterial duct diameter ratio was lower in fetuses with CoA than in those without CoA ( P <0.001). The presence of coarctation shelf and aortic arch hypoplasia were more common in fetuses with CoA than in controls (odds ratio, 26.0; 95% confidence interval, 4.42–153; P <0.001 and odds ratio, 38.2; 95% confidence interval, 3.01–486; P =0.005), whereas persistent left superior vena cava ( P =0.85), ventricular septal defect ( P =0.12), and bicuspid aortic valve ( P =0.14) did not carry an increased risk for this anomaly. Multiparametric diagnostic models integrating different ultrasound signs for the detection of CoA were associated with an increased detection rate. Conclusions: The detection rate of CoA may improve when a multiple-criteria prediction model is adopted. Further large multicenter studies sharing the same imaging protocols are needed to develop objective models for risk assessment in these fetuses.

Objective: Placental insufficiency contributes to the risk of stillbirth. Cerebroplacental ratio (CPR) is an emerging marker of placental insufficiency. The aim of this study was to evaluate the association of third‐trimester fetal CPR, uterine artery (UtA) Doppler and estimated fetal weight (EFW) with stillbirth and perinatal death.Methods: This was a retrospective cohort study including 2812 women with a singleton pregnancy who underwent an ultrasound scan in the third trimester. EFWs were converted into centiles, and Doppler indices (UtA and CPR) were converted into multiples of the median (MoM), adjusting for gestational age. Regression analysis was performed to identify, and adjust for, potential confounders, and receiver–operating characteristics (ROC) curve analysis was used to assess the predictive value.Results: When adjusting for EFW centile and UtA mean pulsatility index (UtA‐PI) MoM, CPR‐MoM remained an independent predictor of stillbirth (odds ratio (OR) = 0.003 (95% CI, 0.00–0.11), P = 0.003) and perinatal mortality (OR = 0.001 (95% CI, 0.00–0.03), P < 0.001). UtA‐PI ≥ 1.5 MoM was significantly associated with low CPR‐MoM, even after adjusting for EFW centile (OR = 5.22 (95% CI, 3.88–7.04), P < 0.001) or small‐for‐gestational age (SGA; OR = 4.73 (95% CI, 3.49–6.41), P < 0.001). These associations remained significant, even when excluding pregnancies with SGA or including only cases in which Doppler indices were recorded at term (P < 0.01). For prediction of stillbirth, the area under the ROC curve, using a combination of these three parameters, was 0.88 (95% CI, 0.77–0.99) with a sensitivity of 66.7%, specificity of 92.1%, positive likelihood ratio (LR) of 8.46 and negative LR of 0.36.Conclusions: Third‐trimester CPR is an independent predictor of stillbirth and perinatal mortality. The role of UtA Doppler, CPR and EFW in assessing risk of adverse pregnancy outcome should be evaluated prospectively. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.