Placenta Accreta

Increasing evidence suggests a relationship between in vitro fertilization-embryo transfer (IVF-ET) and placenta accreta spectrum (PAS). Some studies have reported a lower rate of antenatal diagnosis of PAS after IVF-ET compared to PAS with spontaneous conception. This study aimed to review the diagnostic accuracy of PAS after IVF-ET and to explore the relationship between IVF-ET pregnancy and PAS. According to the PRISMA guidelines, a comprehensive systematic review of the literature was conducted through August 31, 2020 to determine the effects of IVF-ET on PAS. In addition, a meta-analysis was conducted to explore the relationship between IVF-ET pregnancy and PAS. Twelve original studies (2011-2020) met the inclusion criteria. Among these, 190,139 IVF-ET pregnancies and 248,534 spontaneous conceptions met the inclusion criteria. In the comparator analysis between PAS after IVF-ET and PAS with spontaneous conception (n = 2), the antenatal diagnosis of PAS after IVF-ET was significantly lower than that of PAS with spontaneous conception (22.2% versus 94.7%, P < 0.01; < 12.9% versus 46.9%, P < 0.01). The risk of PAS was significantly higher in women who conceived with IVF-ET than in those with spontaneous conception (odds ratio [OR]: 5.03, 95% confidence interval [CI]: 3.34-7.56, P < 0.01). In the sensitivity analysis accounting for the type of IVF-ET, frozen ET was associated with an increased risk of PAS (OR: 4.60, 95%CI: 3.42-6.18, P < 0.01) compared to fresh ET. Notably, frozen ET with hormone replacement cycle was significantly associated with the prevalence of PAS compared to frozen ET with normal ovulatory cycle (OR: 5.76, 95%CI 3.12-10.64, P < 0.01). IVF-ET is associated with PAS, and PAS after IVF-ET was associated with a lower rate of antenatal diagnosis. Therefore, clinicians can pay more attention to the presence of PAS during antenatal evaluation in women with IVF-ET, especially in frozen ET with hormone replacement cycle.

Placenta accreta spectrum (PAS) is a high-risk obstetrical condition associated with significant morbidity and mortality. Current clinical screening modalities for PAS are not always conclusive. Here, we report a nanostructure-embedded microchip that efficiently enriches both single and clustered circulating trophoblasts (cTBs) from maternal blood for detecting PAS. We discover a uniquely high prevalence of cTB-clusters in PAS and subsequently optimize the device to preserve the intactness of these clusters. Our feasibility study on the enumeration of cTBs and cTB-clusters from 168 pregnant women demonstrates excellent diagnostic performance for distinguishing PAS from non-PAS. A logistic regression model is constructed using a training cohort and then cross-validated and tested using an independent cohort. The combined cTB assay achieves an Area Under ROC Curve of 0.942 (throughout gestation) and 0.924 (early gestation) for distinguishing PAS from non-PAS. Our assay holds the potential to improve current diagnostic modalities for the early detection of PAS.

ImportancePlacenta previa is widely acknowledged as a risk factor for placenta accreta spectrum (PAS) disorders, which are severe maternal complications; however, data are limited regarding whether placenta previa is associated with a higher risk of worse maternal outcomes among patients with PAS disorders.ObjectiveTo examine the association between placenta previa and the risk of severe maternal morbidities (SMMs) and higher resource use among patients with PAS disorders.Design, setting, and participantsThis retrospective cohort study extracted records of 3793 patients with PAS diagnosis and delivery indicators between October 1, 2015, and December 31, 2019, from the US National Inpatient Sample database.ExposuresPlacenta previa.Main outcomes and measuresData on 21 Centers for Disease Control and Prevention-defined SMMs and 25 study-defined surgical morbidities associated with PAS were extracted. Six surgical procedures (cystoscopy, intra-arterial balloon occlusion, cesarean delivery, hysterectomy, cystectomy, and oophorectomy), hospital length of stay, and inpatient costs were compared. Multivariable Poisson regression models built in the generalized estimating equation framework were used.ResultsAmong 3793 patients with PAS (median [IQR] age at admission, 33 [29-37] years), 621 women (16.4%) were Black, 765 (20.2%) were Hispanic, 1779 (46.9%) were White, 441 (11.6%) were of other races and/or ethnicities (47 [1.2%] were American Indian, 220 [5.8%] were Asian or Pacific Islander, and 174 [4.6%] were of multiple or other races and/or ethnicities), and 187 (4.9%) were of unknown race and ethnicity. A total of 1323 patients (34.9%) had placenta previa and 2470 patients (65.1%) did not; of those with placenta previa, 405 patients (30.6%) had invasive PAS. Patients with vs without placenta previa had a significantly higher rate and risk of any SMM (935 women [70.7%] vs 1087 women [44.0%]; P Conclusions and relevanceIn this study, placenta previa was associated with an increased risk of maternal and surgical morbidities and higher resource use among women with PAS. These findings suggest that interventions to alleviate maternal and surgical morbidities are especially needed for patients with placenta previa-complicated PAS disorders.

AimTo assess the utility of intraoperative transvaginal ultrasonography (TVUS) in evaluating the duration of blood flow in cervical hypervascularity as a real time diagnostic marker for placenta accreta spectrum (PAS) in placenta previa.MethodsThis single-center historical cohort study included patients with placenta previa with intraoperative TVUS. The primary outcome was blood flow persistence time, defined as the interval from fetal delivery to disappearance of low-velocity (≤ 2.0 cm/s) color Doppler signals in cervical hypervascularity. Two obstetricians independently reviewed surgical video recordings. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic performance of flow persistence time for predicting PAS. The AUC was calculated to assess discrimination. Optimal cutoffs were based on sensitivity and specificity. Independent predictors of PAS were identified by multivariate regression.ResultsPAS was diagnosed in 20 cases (38.5%). Flow persistence time was significantly longer in PAS cases (20.20 ± 14.31 min) than in non-PAS cases (5.69 ± 2.46 min). A cut-off of 7 min achieved 100% sensitivity and 72% specificity (AUC = 0.94), reliably excluding PAS when flow ceased within this period. A threshold of ≥ 14 min yielded 100% positive predictive value for PAS and 96% specificity for predicting hysterectomy. Flow duration remained an independent predictor in multivariable analysis (AUC = 0.95).ConclusionsIntraoperative assessment of cervical hypervascularity blood flow duration using TVUS may serve as a supportive indicator when PAS is suspected. A flow duration of < 7 min may help rule out PAS, while ≥ 14 min may suggest its presence and guide safer intraoperative management.