Ultrasound and magnetic resonance imaging in the diagnosis of clinically significant placenta accreta spectrum disorders

Objectives We aimed to assess the performance of ultrasound (US) and magnetic resonance imaging (MRI) signs for antenatal detection of placenta accreta spectrum (PAS) disorders in women with placenta previa (placental edge ≤2 cm from the internal uterine orifice, ≥260/7 weeks’ gestation) with and without a history of previous Caesarean section. Methods Single center prospective observational study. US suspicion of PAS was raised in the presence of obliteration of the hypoechoic space between uterus and placenta, interruption of the hyperechoic uterine-bladder interface and/or turbulent placental lacunae on color Doppler. All MRI studies were blindly evaluated by a single operator. PAS was defined as clinically significant when histopathological diagnosis was associated with at least one of: intrauterine balloon placement, compressive uterine sutures, peripartum hysterectomy, uterine or hypogastric artery ligature, uterine artery embolization. Results A total of 39 women were included: 7/39 had clinically significant PAS. There were 6/18 cases of PAS with anterior placenta: hypoechoic space interruption and placental lacunae were the most sensitive sonographic signs (83%), while abnormal hyperechoic interface was the most specific (83%). On MRI, focal myometrial interruption and T2 intraplacental dark bands showed the best sensitivity (83%), bladder tenting had the best specificity (100%). 1/21 women with posterior placenta had PAS. There was substantial agreement between US and MRI in patients with anterior placenta (κ=0.78). Conclusions US and MRI agreement in antenatal diagnosis of clinically significant PAS was maximal in high-risk women. Placental lacunae on ultrasound scan and T2 intraplacental hypointense bands on MRI should trigger the suspicion of PAS.

An Ultrasound Scoring Model for the Prediction of Intrapartum Morbidly Adherent Placenta and Maternal Morbidity: A Cross-Sectional Study

Objective To design an ultrasound scoring model for the prediction of the intrapartum morbidly adherent placenta (MAP) and maternal morbidity. Patients and Methods 114 females with singleton pregnancies ≥ 28 weeks of gestation referred for suspicion of MAP were included. All patients underwent examination by two-dimensional ultrasound with the color Doppler setting. Five signs were evaluated: the retroplacental echolucent space, placental lacunae, the hyperechoic uterine-bladder interface, retroplacental myometrium thickness, and subplacental, uterine serosa-bladder wall, intraplacental and bladder wall vascularity. We designed a score ranging from 0 – 8.5 points, including the five signs according to their odds ratios and evaluated its prediction for MAP and maternal morbidity. Results Using multivariate logistic regression, all ultrasound signs were significant dependent predictors for both MAP and maternal morbidity (myometrium thickness < 1 mm followed by lacunae ≥ 4 and lost retroplacental echolucent space). The only independent predictors for MAP were myometrium thickness < 1 mm and lacunae ≥ 4, while myometrium thickness < 1 mm and lost retroplacental echolucent space were predictive for maternal morbidity. The score showed a perfect agreement with MAP and a good one for maternal morbidity. Conclusion Application of the score we designed can improve the ultrasound diagnosis of MAP and the maternal outcome.

Maternal Morbidity in Women with Placenta Previa Managed with Prediction of Morbidly Adherent Placenta by Ultrasonography

Objective. To determine maternal morbidity in women with placenta previa managed with prediction of morbidly adherent placenta (MAP) by ultrasonography. Methods. A retrospective cohort study was undertaken comprising forty-one women who had placenta previa with or without risk factors for MAP. Women who had all three findings (bladder line interruption, placental lacunae, and absence of the retroplacental clear zone) were regarded as high suspicion for MAP and underwent cesarean section followed by hysterectomy. We attempted placental removal for women having two findings or less. Results. Among 28 women with risk, nine with high suspicion underwent hysterectomy and were diagnosed with MAP. Three of 19 women with two findings or less eventually underwent hysterectomy and were diagnosed with MAP. The sensitivity and positive predictive value for the detection of MAP were 64% and 100%. The pathological severity of MAP was significantly correlated with the cumulative number of findings. There were no cases of MAP among 13 women without risk. There was no difference of blood loss between women with high suspicion and those without risk (2186±1438 ml versus 1656±848 ml, resp.; p=0.34). Conclusion. Management with prediction of MAP by ultrasonography is useful for obtaining permissible morbidity.