Abnormally Invasive Placenta Research Articles

Maternal and Neonatal Outcomes Following Abnormally Invasive Placenta: A Population-based Record Linkage Study

(Acta Obstet Gynecol Scand 2017;96:1373–1381) Abnormally invasive placenta (AIP), which includes placenta accreta, increta, and percreta, is associated with serious complications, especially severe postpartum hemorrhage. Several studies have reported an increased prevalence of this condition in conjunction with the increasing cesarean delivery rates in many countries. Most previous studies of AIP have focused only on maternal morbidity and have been limited by small sample sizes. The aim of this population-based Australian study was to examine both maternal and neonatal outcomes after AIP using data from a 10-year period.

Lower uterine segment placental thickness in women with abnormally invasive placenta.

Ultrasound signs of abnormal placental invasion are subjective in nature. We tested the hypothesis that placental thickness in the lower uterine segment is increased when there is abnormally invasive placenta (AIP) in women with a low-lying placenta. Retrospective analysis of data of placental thickness in women with ultrasound evidence of major placenta previa or a low-lying anterior placenta was done. The diagnosis of AIP was confirmed both intraoperatively and on histopathology for those managed by partial myometrial excision with uterine conservation or by hysterectomy. In all, 131 records were available for analysis after exclusion of 33 cases due to unsuitable images and eight cases without pregnancy outcomes. The diagnosis of AIP was confirmed in 28 (21.4%) of the 131 cases. The lower segment placental thickness was significantly higher in women with AIP (median=50.3mm, IQR: 42.7-64.3) than in those with normal placentation (median=30.9mm, IQR: 22.9-42.2, P<0.001). Logistic regression analysis showed that previous cesarean section and placental thickness on ultrasound were independent predictors for AIP. Lower uterine segment placental thickness is increased in women with AIP compared with those with noninvasive placentation. This association constitutes a pragmatic objective sign and may be of clinical value in improving prenatal detection of AIP in women with placental implantation in the lower uterine segment. Prospective studies are necessary to ascertain lower segment placental thickness as a predictor for AIP.

Influence of prenatal diagnosis of abnormally invasive placenta on maternal outcome: systematic review and meta-analysis.

To ascertain the impact of prenatal diagnosis on surgical outcome of women affected by abnormally invasive placenta (AIP). MEDLINE, EMBASE, CINAHL and Cochrane databases were searched. Observed outcomes included: gestational age at birth (weeks), amount of blood loss (L), units of red blood cells (RBC), platelets (PLT) and fresh frozen plasma (FFP) transfused, length of stay in hospital and the intensive care unit (ICU) (days), urinary tract injury and infection. Only studies reporting the occurrence of any of the explored outcomes in women with a prenatal compared with an intrapartum diagnosis of AIP were considered eligible for inclusion. Random-effect head-to-head meta-analyses were used to analyze the data. Thirteen studies were included. Women with a prenatal diagnosis of AIP had less blood loss during surgery (mean difference (MD), -0.87; 95% CI, -1.5 to -0.23), had fewer units of RBC (MD, -1.45; 95% CI, -2.9 to -0.04) and FFP (MD, -1.73; 95% CI, -3.3 to -0.2) transfused, and delivered earlier (MD, 1.33 weeks; 95% CI, -2.23 to -0.43) compared with those with an intrapartum diagnosis. The risk of admission to an ICU and length of in-hospital and in-ICU stay were not different between the groups. Prenatal diagnosis of AIP was associated with a higher risk of urinary-tract injury (odds ratio, 2.5; 95% CI, 1.3-4.6), mainly due to the higher prevalence of placenta percreta in the group with AIP diagnosed prenatally. Prenatal diagnosis of AIP is associated with reduced hemorrhagic morbidity compared with cases in which such anomalies are detected at delivery. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Diagnostic accuracy of first-trimester ultrasound in detecting abnormally invasive placenta in high-risk women with placenta previa.

To ascertain the diagnostic accuracy of ultrasound in detecting abnormally invasive placenta (AIP) during the first trimester of pregnancy (11-14 weeks' gestation) in women at risk for this condition. This was a retrospective analysis of data collected prospectively from women at risk for AIP based upon the presence of at least one prior Cesarean section (CS) and/or uterine surgery and placenta previa, who had ultrasound assessment for AIP at the time of the 11-14-week scan. The ultrasound signs explored in the present study were: loss of the clear zone, placental lacunae, bladder wall interruption and uterovesical hypervascularity. The potential of ultrasound and different ultrasound signs to predict the different types of AIP was assessed by computing summary estimates of sensitivity, specificity, diagnostic odds ratio (DOR) and positive (LR+) and negative (LR-) likelihood ratios. One hundred and eighty-eight women with placenta previa and at least one previous CS or uterine surgery were included in the study. All the explored ultrasound signs were associated significantly with the occurrence of AIP. Overall, when at least one ultrasound sign was used to make the diagnosis, ultrasound had a sensitivity of 84.3% (95% CI, 74.7-91.4%), specificity of 61.9% (95% CI, 51.9-71.2%), DOR of 8.6 (95% CI, 4.1-19.3), LR+ of 2.2 (95% CI, 1.7-2.9) and LR- of 0.3 (95% CI, 0.1-0.4) in detecting AIP. Using two ultrasound signs to label a case as positive increased the diagnostic accuracy in terms of specificity, although it did not affect sensitivity. Among the different ultrasound signs, loss of the clear zone had a sensitivity of 84.3% (95% CI, 74.7-91.4%) and a specificity of 81.9% (95% CI, 73.2-88.7%) in detecting AIP, while sensitivities for placental lacunae and bladder wall interruption were 78.3% (95% CI, 67.9-86.6%) and 75.9% (95% CI, 65.3-84.6%), respectively, and specificities were 81.0% (95% CI, 72.1-88.0%) and 99.1% (95% CI, 94.8-100.0%), respectively. The optimal combination of sensitivity and specificity was achieved when at least two imaging signs of AIP were used in the diagnostic algorithm. AIP can be detected from the first trimester of pregnancy in women at risk for this condition, and ultrasound performed between 11 and 14 weeks' gestation has an overall good diagnostic accuracy for detecting all types of AIP. However, these findings are applicable only to women with placenta previa and prior uterine scar. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Abnormally invasive placenta (AIP): pre-cesarean amnion drainage to facilitate exteriorization of the gravid uterus through a transverse skin incision.

The number of pregnant women with abnormally invasive placenta (AIP) including clinical relevant placenta increta and percreta has markedly increased with a reported incidence of as high as one in 731, By 2020 in the United States, there will be an estimated 4504 new cases of AIP and 130 AIP-associated maternal deaths annually. The preoperative diagnosis and operative management of AIP is challenging. In a planned cesarean delivery, a vertical lower abdominal skin incision is widely used in order to have enough space to perform a hysterotomy above the cranial edge of the placenta to avoid significant fetal and/or maternal hemorrhage. We have used preoperative drainage of the amniotic fluid after epidural anesthesia and immediately before a planned cesarean delivery through a transverse skin incision in five patients with AIP of the anterior uterine wall. With less uterine volume, exteriorization of the gravid uterus is easily performed through a transverse laparotomy. The combination of amnion drainage, transverse laparotomy and exteriorization of the gravid uterus facilitates identification of the exact site of placental implantation, provides adequate space for performing fundal or high anterior or even posterior uterine wall incisions and to deliver the fetus safely while minimizing the risk of placental separation and subsequent uncontrolled blood loss. Furthermore, this technique provides the chance to leave the untouched placenta in situ or to remove the placenta in toto with a uterine wall segment.

Prenatal Diagnosis of Abnormal Invasive Placenta by Ultrasound: Measurement of Highest Peak Systolic Velocity of Subplacental Blood Flow

The aim of the study described here was to identify an efficient criterion for the prenatal diagnosis of abnormal invasive placenta. We evaluated 129 women with anterior placenta previa who underwent trans-abdominal ultrasound evaluation in the third trimester. Spectral Doppler ultrasonography was performed to assess the subplacental blood flow of the anterior lower uterine segment by measuring the highest peak systolic velocity and resistive index. These patients were prospectively followed until delivery and evaluated for abnormal placental invasion. The peak systolic velocity and resistive index of patients with and without abnormal placental invasion were then compared. Postpartum examination revealed that 55 of the patients had an abnormal invasive placenta, whereas the remaining 74 did not. Patients with abnormal placental invasion had a higher peak systolic velocity of the subplacental blood flow in the lower segment of the anterior aspect of the uterus (area under receiver operating characteristic curve: 0.91; 95% confidence interval: 0.87–0.96) than did those without abnormal placental invasion. Our preliminary investigations suggest that a peak systolic velocity of 41 cm/s can be considered a cutoff point to diagnose abnormal invasive placenta, with both good sensitivity (87%) and good specificity (78%), and the higher the peak systolic velocity, the greater is the chance of abnormal placental invasion. Resistive index had no statistical significance (area under receiver operating characteristic curve, 0.56; 95% confidence interval: 0.46–0.66) in the diagnosis of abnormal invasive placenta. In conclusion, measurement of the highest peak systolic velocity of subplacental blood flow in the anterior lower uterine segment can serve as an additional marker of anterior abnormal invasive placenta.

The role of prophylactic internal iliac artery ligation in abnormally invasive placenta undergoing caesarean hysterectomy: a randomized control trial

Objective: To identify the role of bilateral internal iliac artery (IIA) ligation on reducing blood loss in abnormally invasive placenta (AIP) undergoing caesarean hysterectomy.Methods: In this parallel-randomized control trial, 57 pregnant females with ultrasound features suggestive of AIP were enrolled. They were randomized into two groups; IIA group (n = 29 cases) performed bilateral IIA ligation followed by caesarean hysterectomies, while Control group (n = 28 cases) underwent caesarean hysterectomy only. The main outcome was the difference in the estimated intraoperative blood loss between the two groups.Results: There was no significant difference between the two groups regarding the intraoperative estimated blood loss (1632 ± 804 versus 1698 ± 1251, p value .83). The operative procedure duration (minutes) (223 ± 66 versus 171 ± 41.4, p value .001) varied significantly between the two groups.Conclusions: Bilateral internal iliac artery ligation, in cases of AIP undergoing caesarean hysterectomy, is not recommended for routine practice to minimize blood loss intraoperatively.

Random placenta margin incision for control hemorrhage during cesarean delivery complicated by complete placenta previa: a prospective cohort study

Introduction: Complete placenta previa (CPP) is one of the most problematic types of abnormal placenta, which is further complicated by placenta accreta or percreta that can unexpectedly lead to catastrophic blood loss, infection, multiple complications, emergency hysterectomy, and even death. The present study aimed to assess the efficacy of random placenta margin incision in controlling intraoperative and total blood loss during cesarean section for CPP women.Methods: A prospective cohort study, including a total of 100 consecutive pregnant women with CPP, was performed at a tertiary university-affiliated medical center between March 2016 and July 2017. All of them underwent random placenta margin incision, and intraoperative and total blood loss were analyzed. Through antenatal diagnosis using color Doppler, women were further divided into abnormally invasive placenta (AIP) and non-AIP groups, and anterior and posterior placenta groups. The protocol was registered with the Clinical Trial Registry under registration number NCT02695069.Results: Mean maternal age and gestational age at delivery were 32.26 ± 5.03 years old and 36.21 ± 2.07 weeks, respectively. Total duration of the surgical procedure time was 52.50 (42.43–64.00) min. Median estimated intraoperation blood loss was 746.43 (544.44–1092.86) ml. Total blood loss was 875.00 (604.50–1196.67) ml, and 38 (38.0%) had post-partum hemorrhage. The change from baseline in the median hemoglobin level was −0.33 (6.00–13.20). No women underwent hysterectomy due to massive hemorrhage during the study period. No women had an intraoperative urinary bladder injury, postoperative wound infection, and required relaparotomy, owing to intra-abdominal bleeding. The median hospitalization time was 5.41 (4.18–7.58) d.Conclusion: The random placenta margin incision may be a potentially valuable surgical procedure to control the volumes of intraoperative and postoperative blood loss and reduce the incidence of postpartum hemorrhage among women with complete placenta previa.

Diagnostic accuracy of cystoscopy and ultrasonography in the prenatal diagnosis of abnormally invasive placenta.

The aim of this study was to compare the accuracy of cystoscopy and ultrasonography for the prenatal diagnosis of abnormally invasive placenta (AIP), including its subgroups: placenta accreta (PA), placenta increta (PI), and placenta percreta (PP).A retrospective observational study including a total of 85 pregnant women at high risk for AIP underwent prenatal cystoscopy and ultrasonography evaluations. The sensitivity (Se), specificity (Sp), positive predictive value, negative predictive value, and exact diagnosed were calculated and compared for both cystoscopy and ultrasonography. Se and Sp values of cystoscopy and ultrasonography were compared by means of the McNemar test.Of the 85 patients, there were 24 (28.2%) PA, 35 (41.2%) PI, 4 (4.7%) PP, and 22 (25.9%) nonadherent placenta. The mean maternal age and gestational age of delivery were 31.88 ± 4.42 years and 36.14 ± 1.84 weeks, respectively. No one was found to develop any complications with cystoscopy like urinary tract infection, or ureteral injury or perforations. Se in the diagnosis of AIP was 50.8% with ultrasonography and 61.9% for cystoscopy. Sp was 86.4% with cystoscopy and 72.7% for ultrasonography. In subgroups, Se with cystoscopy was 25.0%, 62.9%, and 100.0% in PA, PI, and PP, respectively, and 37.5%, 74.3%, and 100.0%, respectively, for ultrasonography; Sp remained unchanged with 86.4% for cystoscopy and 72.7% for ultrasonography. After McNemar test, no difference was found in either Se or Sp between cystoscopy and ultrasonography in AIP and its subgroups.According to the depth of invasion, the diagnostic value of cystoscopy and ultrasonography is all conspicuous increased and they have similar test validity for prenatal diagnosis of AIP and its subgroups.

Human trophoblast epithelial-mesenchymal transition in abnormally invasive placenta.

Differentiation of first trimester human placental cytotrophoblast (CTB) from an anchorage-dependent epithelial phenotype into the mesenchymal-like invasive extravillous trophoblast (EVT) is crucial in the development of the maternal-fetal interface. We showed previously that differentiation of first trimester CTB to EVT involves an epithelial-mesenchymal transition (EMT). Here we compare the epithelial-mesenchymal characteristics of CTB and EVT derived from normal third trimester placenta or placenta previa versus abnormally invasive placenta (AIP). CTB and EVT were isolated from normal term placenta or placenta previa following Caesarean section and EVT from AIP following Caesarean hysterectomy. Cell identity was validated by measurement of cytokeratin-7 and HLA-G. Comparing normal term CTB with EVT from normal term placenta or placenta previa for differential expression analysis of genes associated with the EMT showed changes in >70% of the genes probed. While demonstrating a mesenchymal phenotype relative to CTB, many of the gene expression changes in third trimester EVT were reduced relative to the first trimester EVT. We suggest that third trimester EVT are in a more constrained, metastable state compared to first trimester equivalents. By contrast, EVT from AIP demonstrate characteristics that are more mesenchymal than normal third trimester EVT, placing them closer to first trimester EVT on the EMT spectrum, consistent with a more invasive phenotype.

First-trimester detection of abnormally invasive placenta in high-risk women: systematic review and meta-analysis.

The primary aim of this systematic review was to ascertain whether ultrasound signs suggestive of abnormally invasive placenta (AIP) are present in the first trimester of pregnancy. Secondary aims were to ascertain the strength of association and the predictive accuracy of such signs in detecting AIP in the first trimester. An electronic search of MEDLINE, EMBASE, CINAHL and Cochrane databases (2000-2016) was performed. Only studies reporting on first-trimester diagnosis of AIP that was subsequently confirmed in the third trimester either during operative delivery or by pathological examination were included. Meta-analysis of proportions, random-effects meta-analysis and hierarchical summary receiver-operating characteristics curve analysis were used to analyze the data. Seven studies, involving 551 pregnancies at high risk of AIP, were included. At least one ultrasound sign suggestive of AIP was detected in 91.4% (95% CI, 85.8-95.7%) of cases with confirmed AIP. The most common ultrasound feature in the first trimester of pregnancy was low implantation of the gestational sac close to a previous uterine scar, which was observed in 82.4% (95% CI, 46.6-99.8%) of cases. Anechoic spaces within the placental mass (lacunae) were observed in 46.0% (95% CI, 10.9-83.7%) and a reduced myometrial thickness in 66.8% (95% CI, 45.2-85.2%) of cases affected by AIP. Pregnancies with a low implantation of the gestational sac had a significantly higher risk of AIP (odds ratio, 19.6 (95% CI, 6.7-57.3)), with a sensitivity and specificity of 44.4% (95% CI, 21.5-69.2%) and 93.4% (95% CI, 90.5-95.7%), respectively. Ultrasound signs of AIP can be present during the first trimester of pregnancy, even before 11 weeks' gestation. Low anterior implantation of the placenta/gestational sac close to or within the scar was the most commonly seen early ultrasound sign suggestive of AIP, although its individual predictive accuracy was not high. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Outcome of Cesarean scar pregnancy managed expectantly: systematic review and meta-analysis.

To explore the outcome in women managed expectantly following the diagnosis of Cesarean scar pregnancy (CSP). An electronic search of MEDLINE, EMBASE and ClinicalTrials.gov databases was performed utilizing combinations of relevant medical subject headings for 'Cesarean scar pregnancy' and 'outcome'. Reference lists of relevant articles and reviews were hand-searched for additional reports. Observed outcomes included: severe first-trimester vaginal bleeding; clinical symptoms (abdominal pain, vaginal bleeding) requiring treatment; uncomplicated miscarriage; complicated miscarriage requiring intervention; first- or second-trimester uterine rupture or hysterectomy; third-trimester bleeding, uterine rupture or hysterectomy; maternal death; incidence of abnormally invasive placenta (AIP); prevalence of placenta percreta; ultrasound signs suggestive of AIP; and live birth. Meta-analyses of proportions using a random-effects model were used to combine data. Cases were stratified based on the presence or absence of embryonic/fetal heart activity at the time of diagnosis. A total of 17 studies (69 cases of CSP managed expectantly, 52 with and 17 without embryonic/fetal heart beat) were included. In women with CSP and embryonic/fetal heart activity, 13.0% (95% CI, 3.8-26.7%) experienced an uncomplicated miscarriage, while 20.0% (95% CI, 7.1-37.4%) required medical intervention. Uterine rupture during the first or second trimester of pregnancy occurred in 9.9% (95% CI, 2.9-20.4%) of cases, while hysterectomy was required in 15.2% (95% CI, 3.6-32.8%) of all cases. Forty (76.9% (95% CI, 65.4-86.5%)) women progressed to the third trimester of pregnancy, of whom 39.2% (95% CI, 15.4-66.2%) experienced severe bleeding. Finally, 74.8% (95% CI, 52.0-92.1%) had a surgical or pathological diagnosis of AIP at delivery and around two-thirds (69.7% (95% CI, 42.8-90.1%)) of them had placenta percreta. In women with CSP but no embryonic/fetal cardiac activity, an uncomplicated miscarriage occurred in 69.1% (95% CI, 47.4-87.1%) of cases, while surgical or medical intervention during or immediately after miscarriage was required in 30.9% (95% CI, 12.9-52.6%). Uterine rupture during the first trimester of pregnancy occurred in 13.4% (95% CI, 2.7-30.3%) of cases, but hysterectomy was not required in any case. CSP with positive embryonic/fetal heart activity managed expectantly is associated with a high burden of maternal morbidity including severe hemorrhage, early uterine rupture, hysterectomy and severe AIP. Despite this, a significant proportion of pregnancies complicated by CSP may progress to, or close to, term, thus questioning whether termination of pregnancy should be the only therapeutic option offered to these women. Expectant management of CSP with no cardiac activity may be a reasonable option in view of the low likelihood of maternal complications requiring intervention, although close surveillance is advisable to avoid adverse maternal outcome. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Changes in ultrasonography indicators of abnormally invasive placenta during pregnancy.

To ascertain whether the prevalence of ultrasonography signs of abnormally invasive placenta (AIP) changes during pregnancy. The present retrospective analysis included women with a prenatal diagnosis of AIP that was confirmed at delivery between January 1, 2007, and April 30, 2017, at the Department of Obstetrics and Gynaecology, Arnas Civico Hospital, Palermo, Italy. Ultrasonography signs of AIP were recorded at four different intervals during pregnancy: early first (6-9weeks), first (11-14weeks), second (15-24weeks), and third trimester (25-36weeks). There were 105 pregnancies included. Low implantation of the gestational sac was present on all ultrasonography images from the early first trimester compared with on 23 of 83 (27.7%) images from 11-14weeks of pregnancy. The identification of loss of the clear space, placental lacunae, bladder wall interruption, and uterovesical hypervascularity all increased (all P<0.001) from the early first trimester onwards; these could all be identified in a majority of patients at 11-14weeks of pregnancy. The prevalence of ultrasonography signs suggestive of AIP varied throughout pregnancy. During the early first trimester, indicators of AIP were similar to those of a cesarean scar pregnancy; classical ultrasonography signs of AIP were already present at 11-14weeks of pregnancy for most patients.

First-trimester prediction of surgical outcome in abnormally invasive placenta using the cross-over sign.

Ultrasound assessment of the relationship between the ectopic gestational sac and the endometrial line (cross-over sign; COS) in Cesarean scar pregnancy (CSP) has been shown to be useful in predicting the evolution of CSP towards different types of abnormally invasive placenta (AIP). The aim of this study was to ascertain whether the COS can be used to predict surgical outcome in women with AIP. A retrospective analysis was performed of early first-trimester (6-8 weeks' gestation) ultrasound images of women with AIP managed in the third trimester of pregnancy. We hypothesized that assessment of COS may identify cases of AIP at higher risk of intra- or postsurgical morbidity. Outcomes explored were estimated blood loss during surgery, need for and amount of packed red blood cells and fresh frozen plasma units required either during or after surgery, operative time, intrasurgical complications, gestational age at birth, delivery < 34 weeks of gestation, length of hospital stay and admission to intensive care unit. Differences in the explored outcomes were assessed among women with different types of COS variant (COS-1, COS-2+ or COS-2-) as observed on first-trimester ultrasound examination. Sixty-eight pregnancies were included in the study. Mean estimated blood loss was higher in AIP pregnancies with COS-1 than in those with COS-2+ (P = 0.039) or COS-2- (P = 0.01). Mean number of packed red blood cell units required during or after the operation was higher in women with COS-1 compared with those with COS-2+ (P = 0.001) and COS-2- (P = 0.029), while there was no difference between pregnancies with COS-2+ and those with COS-2- (P = 0.797). Mean operative time was longer in AIP pregnancies with COS-1 than in those with COS-2+ (P = 0.039) or COS-2- (P = 0.017). Finally, pregnancies with COS-1 were delivered earlier than those with COS-2+ (P = 0.0001) or COS-2- (P = 0.0001). First-trimester ultrasound assessment of the relationship between the ectopic gestational sac and the endometrial line (COS) may identify women with AIP who are at higher risk of intra- or postsurgical morbidity. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Automatic Lacunae Localization in Placental Ultrasound Images via Layer Aggregation.

Accurate localization of structural abnormalities is a precursor for image-based prenatal assessment of adverse conditions. For clinical screening and diagnosis of abnormally invasive placenta (AIP), a life-threatening obstetric condition, qualitative and quantitative analysis of ultrasonic patterns correlated to placental lesions such as placental lacunae (PL) is challenging and time-consuming to perform even for experienced sonographers. There is a need for automated placental lesion localization that does not rely on expensive human annotations such as detailed manual segmentation of anatomical structures. In this paper, we investigate PL localization in 2D placental ultrasound images. First, we demonstrate the effectiveness of generating confidence maps from weak dot annotations in localizing PL as an alternative to expensive manual segmentation. Then we propose a layer aggregation structure based on iterative deep aggregation (IDA) for PL localization. Models with this structure were evaluated with 10-fold cross-validations on an AIP database (containing 3,440 images with 9,618 labelled PL from 23 AIP and 11 non-AIP participants). Experimental results demonstrate that the model with the proposed structure yielded the highest mean average precision (mAP=35.7%), surpassing all other baseline models (32.6%, 32.2%, 29.7%). We argue that features from shallower stages can contribute to PL localization more effectively using the proposed structure. To our knowledge, this is the first successful application of machine learning to placental lesion analysis and has the potential to be adapted for other clinical scenarios in breast, liver, and prostate cancer imaging.

Diagnostic accuracy of magnetic resonance imaging in detecting the severity of abnormal invasive placenta: a systematic review and meta-analysis.

Accurate prenatal diagnosis of abnormally invasive placenta (AIP) is fundamental because it significantly reduces maternal morbidities. Medline, Embase, CINAHL and the Cochrane databases were searched. The primary aim of the present review was to elucidate the diagnostic accuracy of prenatal magnetic resonance imaging (MRI) in recognizing the severity of AIP, defined as the depth and topography of invasion. The secondary aim was to ascertain the strength of association between each MRI sign and the depth of placental invasion and to test their individual predictive accuracy in detecting such invasion. Inclusion criteria were studies on women who had prenatal MRI for ultrasound suspicion or the presence of clinical risk factors for AIP. Estimates of sensitivity, specificity, positive and negative likelihood ratios and diagnostic odds ratio were calculated using the hierarchical summary receiver characteristics curve model, and individual data random-effect logistic regression was used to calculate OR. Twenty studies (1080 pregnancies undergoing MRI mainly for the ultrasound suspicion of AIP) were included. MRI showed a sensitivity of 94.4% [95% confidence interval (CI) 15.8-99.9], 100% (95% CI 75.3-100) and 86.5% (95% CI 74.2-94.4) for detection of placenta accreta, increta and percreta, respectively; the corresponding values for specificity were 98.8% (95% CI 70.7-100), 97.3% (95% CI 93.3-99.3), 96.8% (95% CI 93.5-98.7). MRI identified 100% of cases with S1 and 100% of those with S2 invasion confirmed at surgery. Among the different MRI signs, intra-placental dark bands showed the best sensitivity for the detection of placenta accreta, increta and percreta; as well as abnormal intra-placental vascularity, uterine bulging was associated with a higher risk of increta and percreta, exophitic mass and bladder tenting with placenta percreta. Prenatal MRI has an excellent diagnostic accuracy in identifying the depth and the topography of placental invasion. However, these findings come mainly from studies in which MRI was performed as a secondary imaging tool in women already screened for AIP on ultrasound and might not reflect its actual diagnostic performance in detecting the severity of these disorders.

Total abnormal invasive placenta in a woman with a history of placental abruption and severe hemorrhage

Abstract Abnormal invasive placenta (AIP) is subdivided into total, partial and focal types. A diagnosis of total AIP is made when the entire placenta adheres to the uterine myometrium. We experienced a patient with total AIP who had a history of an emergency cesarean section at 36 weeks of gestation due to placental abruption, and massive hemorrhage due to severe uterine atony treated conservatively with blood transfusion. From our experience with the present case, we hypothesize that total AIP resulted from thinning of the entire endometrium, as can occur with an ischemic change of the entire uterus after disruption of Nitabuch’s layer in severe placental abruption and intramuscular extravasation with uterine atony. This situation might adversely affect placental implantation in the current pregnancy.

The Jellyfish Sign: A New Sonographic Cervical Marker toPredict Maternal Morbidity in Abnormally Invasive Placenta Previa.

To investigate the value of a new cervical sonographic sign, called the jellyfish sign (JS), for predicting the risk of maternal morbidity in cases of abnormally invasive placenta (AIP) previa totalis. Retrospective evaluation of transvaginal (TV) and transabdominal (TA) scans performed in all singleton pregnancies with placenta previa totalis. JS, i. e. theabsence of the normal linear demarcation between the placenta previa and the cervix, was evaluated by TV scans. The presence/severity of AIP and outcomes of maternal morbidity were related to this sign. JS was noted in 8/39 (20.5 %) patients. The two analyzed groups, i. e. with and without JS, were similar. The specificity of JS in AIP diagnosis, histological findings of accreta/increta/percreta, need for caesarean hysterectomy or blood loss > 2000 ml ranges between 92 % and 96.2 %, with the PPV and NPV ranging between 71.4 % and 85.7 % and 61.3 % and 80.6 %, respectively. The JS group had a significant increase in blood loss (ml) (p = 0.003), transfusions (%) (p = 0.016), red blood cells (p = 0.002) and plasma (p = 0.002), admission to an postoperative intensive care unit (ICU) (%) (p = 0.002), hospitalization length (p < 0.001) and the need of cesarean hysterectomy (%) (p < 0.001). JS was independently correlated to cesarean hysterectomy (OR 25.6; 95 % CI 2.0:322.3, p = 0.012) and blood loss > 2000 ml (OR 16.6; 95 % CI 1.5:180.1, p = 0.021) also in a logistic regression model. JS is useful in predicting the increase in maternal morbidity: massive transfusion, admission to the ICU and cesarean hysterectomy related to intraoperative bleeding in patients with a previa AIP.

Intentional placental removal on suspicious placenta accreta spectrum: still prohibited?

Intentional placental removal for abnormally invasive placenta (AIP) is fundamentally abandoned at planned surgery for it. Whether this holds true even after recent introduction of various hemostatic procedures is unclear. We discussed on this issue based on our own experiences and also on the recent reports on various hemostatic procedures. Studies directly answering this question have been lacking. We must weigh the balance between the massive bleeding and possibility of uterus-preservation when intentional placental removal strategy is employed. An almost forgotten strategy, the "intentional placental removal" for planned AIP surgery may regain its position when appropriate hemostatic procedures are concomitantly used depending on the situation. Even employing this strategy, quick decision to perform hysterectomy under multidisciplinary team may be important.

OP27.04: Comparison of transabdominal ultrasound (US) versus transvaginal US in the accurate prenatal assessment of abnormally invasive placenta (AIP)

To study if adding transvaginal Ultrasound (TVS) exam using grey scale and Doppler parameters to transabdominal ultrasound TAS improves the accuracy of prenatal diagnosis of Abnormally invasive placenta AIP. Pregnant women with persistent placenta previa after 28 weeks' gestation attending the antenatal care at Cairo University Obstetrics department were prospectively included. History taking included number of prior Caesarean sections. All patients underwent TAS & TVS using gray-scale & colour Doppler by two different senior operators, assessing the following criteria: Loss of the retro placental clear zone, thinning or interruption of the uterine serosa–bladder wall interface, myometrial thickness<1mm, turbulent placental lacunae with high velocity flow (>15 cm/s), increased vascularity of the uterine serosa–bladder wall interface. Data collection included full surgical management. Fifty patients underwent US evaluation and were delivered by Caesarean section at Cairo University hospital. The mean age of the patients was 32.6, mean number of previous Caesarean sections was 3. Forty three cases with abnormal invasion of placenta were correctly diagnosed before delivery all of whom proceeded directly to Caesarean hysterectomy & AIP was confirmed by histopathology. There was good agreement between TAS & TVS in diagnosing AIP however the presence of abnormal lacunae & loss of the retro placental clear zone as seen by TVS had the highest sensitivity, specificity NPV, PPV & accuracy; 93.0%, 57.1%, PPV 93.0%, NPV 57.1%, accuracy 88.0% & 74.4%, 85.7%,97.0%, 35.3%, 76.0% respectively. There was no statistical difference in diagnostic ability of US criteria when comparing TAS to TVS except for Loss of the retro placental clear zone which was significantly better seen by TVS (0.003). AIP can be diagnosed with good accuracy antenatal using TAS, adding TVS could aid in diagnostic accuracy especially when retro placental clear zone & abnormal lacunae are seen.