MRI prognosticators for adverse maternal and neonatal clinical outcome in patients at high risk for placenta accreta spectrum (PAS) disorders

Abstract

Background Placenta accreta spectrum (PAS) disorders may be associated with significant mortality and morbidity for both mother and fetus. Purpose/Hypothesis To identify MRI risk factors for poor peripartum outcome in gravid patients at risk for PAS. Study Type Prospective. Population One hundred gravid women (mean age: 34.9 years) at third trimester, with placenta previa. Field Strength/Sequence T2‐SSTSE (single‐shot turbo spin echo), T2‐TSE, T1‐TSEFS (TSE images with fat‐suppression) at 1.5T. Assessment Fifteen MRI features considered indicative of PAS were recorded by three radiologists and were tested for any association with the following adverse peripartum maternal and neonatal events: increased operation time, profound blood loss, hysterectomy, bladder repair, ICU admission, prematurity, low birthweight, and 5‐minute APGAR score <7. Statistical Tests Kappa (K) coefficients were computed as a measure of agreement between intraoperative information/histology and MRI results as well as for interobserver agreement; chi‐square and Fisher's exact tests were used to explore the association of the MRI signs with clinical complications. A score was calculated by adding all recorded MRI signs and its predictive ability was tested using receiver operating characteristic (ROC) analysis, against all complications, separately; odds ratios (ORs) for optimal cutoffs were determined with logistic regression analysis. Results There was excellent agreement (K >0.75, P < 0.001) between MRI and intraoperative findings for invasive placenta, bladder and parametrial involvement. Intraplacental T2 dark bands, myometrial disruption, uterine bulge, and hypervascularity at the utero‐placental interface or parametrium, showed significant association (P < 0.005) with poor clinical outcome for both mother and fetus. The MRI score showed significant predictive ability for each adverse maternal event (area under the curve [AUC]: 0.85–0.97, P < 0.001). The presence of ≥3 MRI signs was the cutoff point for a complicated delivery (OR: 19.08, 95% confidence interval [CI]: 6.05–60.13) and ≥6 MRI signs was the cutoff point for massive bleeding (OR: 90.93, 95% CI: 11.3–729.23), hysterectomy (OR: 72.5, 95% CI: 17.9–293.7), or extensive bladder repair (OR: 58.74, 95% CI: 7.35–469.32). The MRI score was not significant for predicting adverse neonatal events including preterm delivery (P = 0.558), low birthweight (P = 0.097), and 5‐minute Apgar score (P = 0.078). Data Conclusion Preoperative identification of specific MRI features may predict peripartum course in high‐risk patients for PAS. Level of Evidence: 1 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;50:602–618.

Risk Factors and Pregnancy Outcome in Women With a History of Cesarean Section Complicated by Placenta Accreta

“…This study also showed that the incidence of DIC in the PA group was higher, which may be related to the incidence of PPH and an insu cient endogenous supply of coagulation factors. In the present study, the incidence of puerperal infection and intraoperative bladder injury in the PA group was signi cantly increased (P<0.05), which is consistent with a previous report [32]. In addition, we found that the rate of hysterectomy, low birth weight, neonatal comorbidities, and time to NICU admission in the PA group were also signi cantly increased (P<0.05), which was consistent with the results of several previous investigations [23,33,34].…”

Texture analysis of dark intraplacental bands on T2WI in the evaluation of placenta accreta spectrum disorders: a feasibility study

“…It was reported that PAS disorders remained undiagnosed before delivery in half to two-thirds of cases [16,31]. Current prenatal diagnosis mainly rests on subjective interpretation of US and MRI ndings [16].US is the rst-level imaging modality to assess PAS disorders due to its convenience and lower cost [12,23]. However, it suffers from high operator-dependence and low reproducibility.…”

“…The clinical history of PAS disorders is considered as an e cient reference standard to be used in both research and clinical settings, that is, di cult manual, piecemeal removal of the placenta, absence of spontaneous placental separation 20 to 30 minutes after birth despite active management including bimanual massage of the uterus, use of oxytocin and controlled traction of the umbilical cord, retained placental fragment requiring curettage after vaginal birth and heavy bleeding from the placentation site after removal of the placenta during cesarean delivery [19,20 ]. It has good reliability and validity rates compared with other diagnostic standards, such as histopathology [5,12,21,22].…”

“…Ultrasonography (US) had a lower diagnostic accuracy in detecting PAS disorders than MRI, which had a sensitivity 66%, speci city 71% and accuracy 68% [9,10]. Even though US is the frontline imaging modality for the evaluation of PAS disorders [11], MRI is used as a problem-solving tool for equivocal sonographic ndings or suspicion of posterior/lateral placental extension [12][13][14]. No matter what kind of imaging modality is used, prenatal diagnosis of PAS disorders remains subjective, with accuracy depending on the experience of the operator, which has been limited by the lack of training programs similar to that existing for the screening of fetal congenital defects [15,16].…”

Magnetic Resonance Imaging of Placenta Accreta Spectrum: A Step-by-Step Approach

“…During image interpretation, none of these MRI features are assessed in isolation, and the more the features that are identified, the greater the concern. Bourgioti et al (28) correlated specific MR features with clinical outcomes; and found that the presence of ≥ 3 MRI signs correlated with a complicated delivery, while ≥ 6 MRI signs were associated with massive bleeding, a hysterectomy, or extensive bladder repair.…”