Abnormal placentation

Magnetic Resonance Imaging-Based Radiomics Nomogram to Predict Intraoperative Hemorrhage of Placenta Previa

OBJECTIVE

Placenta previa (PP) is associated with intraoperative and postpartum hemorrhage, increased maternal morbidity and mortality. We aimed to develop a magnetic resonance imaging (MRI)-based nomogram to preoperative prediction of intraoperative hemorrhage (IPH) for PP.

STUDY DESIGN

A total of 125 PP pregnant women were divided into a training set (n = 80) and a validation set (n = 45). An MRI-based model was built for the classification of patients into IPH and non-IPH groups in a training set and a validation set. Multivariate nomograms were built according to radiomics features. Receiver operating characteristic (ROC) curve was used to assess the model. Predictive accuracy of nomogram were assessed by calibration plots and decision curve analysis.

RESULTS

In multivariate analysis, placenta position, placenta thickness, cervical blood sinus, and placental signals in the cervix were significantly independent predictors for IPH (all ps < 0.05). The MRI-based nomogram showed favorable discrimination between IPH and non-IPH groups. The calibration curve showed good agreement between the estimated and the actual probability of IPH. Decision curve analysis also showed a high clinical benefit across a wide range of probability thresholds. Area under the ROC curve was 0.918 (95% confidence interval [CI]: 0.857-0.979) in the training set and 0.866 (95% CI: 0.748-0.985) in the validation set by the combination of four MRI features.

CONCLUSION

The MRI-based nomograms might be a useful tool for the preoperative prediction of IPH outcomes for PP. Our study enables obstetricians to perform adequate preoperative evaluation to reduce blood loss and cesarean hysterectomy.

KEY POINTS

· MRI is an important method for preoperative assessment of the risk of placenta previa.. · MRI-based nomogram can assess the risk of intraoperative bleeding of placenta previa.. · MRI is helpful for more comprehensive evaluation of placenta previa and adequate preoperative preparation..

Uterine artery embolization for postpartum hemorrhage with placenta accreta spectrum

BACKGROUND

The reported success rate of uterine artery embolization (UAE) for postpartum hemorrhage (PPH) differs by the cause of bleeding; in some reports, UAE shows less successful results in patients with placenta accreta spectrum (PAS).

PURPOSE

To evaluate the outcome of UAE for treating PPH associated with PAS.

MATERIAL AND METHODS

From September 2011 to September 2021, 227 patients (mean age = 34.67±4.06 years; age range = 19-47 years) underwent UAE for managing intractable PPH. Patients were divided into two groups: those with PAS (n = 46) and those without PAS (n = 181). Delivery details, embolization details, and procedure-related outcomes were compared between the two groups. P values <0.05 were considered statistically significant.

RESULTS

The technical success rate was 96.9% (n = 222) and the clinical success rate was 93.8% (n = 215). There were no significant differences in outcome of UAE between the two patient groups. The technical success rate was 95.7% (n = 44) in patients with PAS and 98.3% (n = 178) in patients without PAS (P = 0.267). The clinical success rate was 91.3% (n = 42) in patients with PAS and 95.6% (n = 173) in patients without PAS (P = 0.269). There were 24 cases of immediate complications, including pelvic pain (n = 20), urticaria (n = 3), and puncture site hematoma (n = 1). No major complication was reported.

CONCLUSION

UAE is a safe and effective method to control intractable PPH for patients with or without PAS.

Development of the Mouse Placenta

Placenta forms as a momentary organ inside the uterus with a slew of activities only when the woman is pregnant. It is a discoid-shaped hybrid structure consisting of maternal and embryonic components. It develops in the mesometrial side of the uterus following blastocyst implantation to keep the two genetically different entities, the mother and embryo, separated but connected. The beginning and progression of placental formation and development following blastocyst implantation coincides with the chronological developmental stages of the embryo. It gradually acquires the ability to perform the vascular, respiratory, hepatic, renal, endocrine, gastrointestinal, immune, and physical barrier functions synchronously that are vital for fetal development, growth, and safety inside the maternal environment. The uterus ejects the placenta when its embryonic growth and survival supportive roles are finished; that is usually the birth of the baby. Despite its irreplaceable role in fetal development and survival over the post-implantation progression of pregnancy, it still remains unclear how it forms, matures, performs all of its activities, and starts to fail functioning. Thus, a detailed understanding about normal developmental, structural, and functional aspects of the placenta may lead to avoid pregnancy problems that arise with the placenta.

Intravoxel incoherent motion MR imaging analysis for diagnosis of placenta accrete spectrum disorders: A pilot feasibility study

BACKGROUND

Placenta accreta spectrum (PAS) disorders occur when the placenta adheres abnormally to the uterine myometrium and can have devastating effects on maternal health due to risks of massive postpartum hemorrhage and possible need for emergency hysterectomy. PAS can be difficult to diagnose using routine clinical imaging with ultrasound and structural MRI.

OBJECTIVE

To determine feasibility of using intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI) analysis in the diagnosis of the placenta accreta spectrum disorders in pregnant women.

METHODS

A total of 49 pregnant women were recruited including 14 with pathologically confirmed cases of PAS and 35 health controls without prior cesarean delivery and no suspected PAS by ultrasound. All women underwent diffusion-weighted imaging with an 8 b-value scanning sequence. A semi-automated method for image processing was used, creating a 3D object map, which was then fit to a biexponential signal decay curve for IVIM modeling to determine slow diffusion (D_s), fast diffusion (D_f), and perfusion fraction (P_f).

RESULTS

Our results demonstrated a high degree of model fitting (R² ≥ 0.98), with P_f significantly higher in those with PAS compared to healthy controls (0.451 ± 0.019 versus 0.341 ± 0.022, p = 0.002). By contrast, no statistical difference in the D_f (1.70 × 10^-2 ± 0.38 × 10^-2 versus 1.48 × 10^-2 ± 0.08 × 10^-2 mm²/s, p = 0.211) or D_s (1.34 × 10^-3 ± 0.10 × 10^-3 versus 1.45 × 10^-3 ± 0.007 × 10^-3 mm²/s, p = 0.215) was found between subjects with PAS and healthy controls.

CONCLUSIONS

The use of MRI, and IVIM modeling in particular, may have potential in aiding in the diagnosis of PAS when other imaging modalities are equivocal. However, the widespread use of these techniques will require generation of large normative data sets, consistent sequencing protocols, and streamlined analysis techniques.

Successful management of uncontrolled postpartum hemorrhage due to morbidly adherent placenta with Resuscitative endovascular balloon occlusion of the aorta during emergency cesarean section - A case report

Background

Morbidly adherent placenta (MAP) may cause life-threatening postpartum hemorrhage (PPH) requiring massive transfusions. Furthermore, it could endanger the lives of both mother and baby. Despite various efforts, such as adjuvant endovascular embolization and hysterectomy, massive PPH due to MAP still occurs and is difficult to overcome.

Case

Herein, we described the case of a 40-year-old woman with placenta previa totalis who experienced massive bleeding during a cesarean section. We used resuscitative endovascular balloon occlusion of the aorta (REBOA) and it improved the condition of the surgical field and the hemodynamic stability of the patient temporarily. The patient was successfully managed without further complications.

Conclusions

REBOA can be used as a rescue procedure for uncontrolled bleeding situations in patients with MAPs. Anesthesiologists should consider and recommend REBOA as another resuscitative therapeutic option in the case of massive PPH.

Cesarean delivery with and without uterine artery embolization for the management of placenta accreta spectrum disorder-A comparative study

INTRODUCTION

The aim of this study is to compare immediate and long-term obstetrical outcomes of patients who underwent cesarean delivery with and without uterine artery embolization (UAE) for the management of placenta accreta spectrum disorder.

MATERIAL AND METHODS

A retrospective case control study including all pregnant women admitted to a single tertiary medical center between December 2001 and May 2018 with a diagnosis of placenta accreta spectrum disorder, who underwent cesarean delivery with and without UAE. Groups were compared for maternal characteristics, operative management, postoperative complication rate and long-term outcomes. Follow up on future obstetrical outcomes was conducted via telephone questionnaire. Non-parametric statistics were used.

RESULTS

During the study period, 272 women met the inclusion criteria: 64 (23.53%) and 208 (76.47%) underwent preservative cesarean section with and without UAE, respectively. UAE procedure was associated with a longer operative time (82.5 [68-110] vs 50.5 [39-77] minutes; P = .001), and higher blood loss (2000 (1500-3000) vs 1000 (600-2000) mL; P = .001). Hysterectomy rate was comparable between the groups (9 [14%] vs 35 [16.82%]; P = .88); however, multivariate logistic regression analysis found UAE to be an independent factor associated with lower hysterectomy rate (P = .02). Postoperative complications were more frequent in the UAE group. Follow up was achieved in 29 (59.18%) and 72 (51.79%) of the women with and without UAE, respectively (P = .36). No differences were found in rate of abortions, pregnancy and deliveries between the groups.

CONCLUSIONS

Cesarean delivery using UAE in placenta accreta spectrum disorder is associated with a higher rate of operative and postoperative complications. Nevertheless, in cases of severe adherence of the placenta, embolization reduces the need for hysterectomy, allowing future fertility.

Uterine body placenta accreta spectrum: A detailed literature review

Placenta accreta spectrum (PAS) is a major obstetrical problem whose incidence is rising. Current guidelines recommend screening of all women with placenta previa and risk factors for PAS between 20 and 24 weeks. Risk factors, diagnosis, and management of previa PAS are well established, but an apparently normal location of the placenta does not exclude PAS. Literature data are scarce on uterine body PAS, which carries a high risk of maternal and neonatal adverse outcome, but is still easily missed on prenatal ultrasound. We conducted a comprehensive review to identify possible risk factors, clinical presentations, and diagnostic modalities of uterine PAS. A total of 133 cases were found during a 70-year period (1949-2019). The vast majority of them presented with signs of uterine rupture, even prior to the viability threshold of 24 weeks (up to 45%). Major risk factors included previous cesarean delivery, uterine curettage, uterine surgery, Asherman's syndrome, manual removal of the placenta, endometritis, high parity, young maternal age, in vitro fertilization, radiotherapy, uterine artery embolization, and uterine leiomyoma. Diagnosis was pre-symptomatic in only 3% of cases. Future studies should differentiate between previa PAS and uterine body PAS.

Intraoperative cell salvage as part of a blood conservation strategy in an obstetric population with abnormal placentation at a large Irish tertiary referral centre: an observational study

BACKGROUND

Haemorrhagic morbidity is more common in women with abnormal placentation, that is placenta praevia or morbidly adherent placenta. The incidence of abnormal placentation is increasing due to rising caesarean section rates. Concerns regarding blood safety, blood shortages and soaring costs of blood processing have generated growing enthusiasm for blood conservation strategies. The aim of our study was to look at intraoperative cell salvage (IOCS) use and allogeneic transfusion patterns in patients with abnormal placentation.

METHODS

Patients with abnormal placentation were identified from the hospital database over a 2-year period between 2015 and 2016. Information collected for those that had IOCS setup included estimated blood loss, volume of blood collected and returned, pre- and postoperative haemoglobin levels and use of allogeneic blood.

RESULTS

A total of 139 cases of abnormal placentation were identified. Abnormal placentation accounted for 62% of all cases of IOCS usage and was established for 53 patients with abnormal placentation. The re-transfusion rate was 18.5%. Five patients received IOCS blood only. The allogeneic transfusion rate was 7.5% in patients who had IOCS setup compared with 6.9% in those who did not (p = 1.00). Median blood loss was greater for patients who had IOCS blood returned compared with patients who had not (p = 0.004). The median volume of blood returned was 520 (114-608) mL. Preoperative haemoglobin levels were lower for patients who received a combination of cell salvage and allogeneic blood (p = 0.006).

CONCLUSIONS

IOCS contributed to a reduction or elimination of allogeneic transfusion for a proportion of this high-risk cohort and should be an integral component of a hospitals' blood conservation strategy.

Can introvoxel incoherent motion MRI be used to differentiate patients with placenta accreta spectrum disorders?

BACKGROUND

The incidence of PAS disorders increased rapidly in recent years, and introvoxel incoherent motion (IVIM) MRI has been applied in the assessment of placenta. The study aims to investigate whether the parameters from IVIM can be used to differentiate patients with PAS disorders complicating placenta previa and secondly to differentiate different categories of PAS disorders.

METHODS

The study participants were comprised of 99 patients with placenta previa, including 16 patients with placenta accreta, 51 patients with increta, 8 patients with percreta and 24 patients without PAS disorders between 28 + 0 and 39 + 6 weeks. IVIM MRI was performed on a 1.5 T scanner. Perfusion fraction (f), pseudodiffusion coefficient (D*) and diffusion coefficient (D) were calculated.

RESULTS

Women with PAS disorders had a higher perfusion fraction (p = 0.019) than women without the disease. Multiple comparisons showed perfusion fraction in patients without PAS disorders was significantly lower than in patients with placenta accreta and percreta(P = 0.018 and 0.033 respectively), but was not lower than in patients with increta(p = 1).

CONCLUSION

Patients with placenta accreta and percreta differed in placental perfusion fraction from women with increta and without PAS disorders.

Prophylactic intraoperative uterine or internal iliac artery embolization in planned cesarean for pernicious placenta previa in the third trimester of pregnancy: An observational Study (STROBE compliant)

The aim of this study was to evaluate the efficacy and safety of prophylactic intraoperative bilateral uterine or internal iliac artery embolization in planned cesarean for pernicious placenta previa in the third trimester of pregnancy.The patients with pernicious placenta previa were retrospectively included from January 2011 to May 2018, being divided into embolization group and control group. Intraoperative uterine artery embolization (UAE) or internal iliac artery embolization (IIAE) was undertaken to stop intrapartum and postpartum hemorrhage in embolization group.There were no significant differences on age, pregnancy times, gestational age, neonatal weight, neonatal asphyxia, prenatal bleeding, placental implantation, and mortality between embolization group and control group (P > .05). The amount of intraoperative and postoperative bleeding in embolization group was significantly greater than that in control group (P < .05). However, the hysterectomy rate in the embolization group was significantly lower than that in the control group (P < .05). Two (6.25%, 2/32) cases had undergone the second time embolotherapy after 8 hours of cesarean surgery because of severe vaginal bleeding. One case (3.13%, 1/32) died of diffuse intravascular coagulation because of hemorrhagic shock in embolization group. Transient and self-remitted lumbosacral pain was present in 28 (95%, 28/32) patients and no other severe interventional complications were reported in embolization group. All babies in 2 groups were healthy at half to 5 years' follow-up.The prophylactic intraoperative embolization of bilateral UAE or IIAE may be an effective strategy to treat intractable peripartum hemorrhage and preserve the fertility in patients with pernicious placenta previa.

Identification of protein patterns in bovine placenta at early-mid pregnancy - Pilot studies

RATIONALE

Placenta is a crucial tissue for an appropriate development of the fetus and the course of pregnancy. Its composition and structure change dynamically along pregnancy but the full pattern of these changes is not fully described in cows yet. The aim of the present study was to detect qualitative and quantitative protein profiles of bovine placenta during early-mid pregnancy at the time of placental formation.

METHODS

Placental tissues from healthy cows (n = 3) in early pregnancy (3-5 months) were collected at the slaughterhouse. Maternal and fetal parts were manually divided prior to homogenization. Further analysis was done in triplicates on the maternal and fetal parts separately and subjected to one-dimensional (1D) electrophoretic separation, followed by identification of peptide maps by nanospray liquid chromatography/tandem mass spectrometry (nanoLC/MS/MS). Proteins were identified by use of the MASCOT software with the SwissProt database.

RESULTS

Proteomic analysis showed more than 4000 differentially expressed proteins in maternal and fetal parts of placenta. Each part expressed around 900 proteins, of which ca. 90 were common. The identified proteins were analyzed in accordance to molecular function and their participation in biological processes.

CONCLUSIONS

The obtained results provide new insight into the knowledge about biochemical characteristics of placenta (new proteins) and serve for further studies on the possible markers of physiological/pathological pregnancy or function of placenta. Moreover, our data can be a good starting point for further studies on the processes underlying the attachment of placenta.

Comparison of infrarenal aortic balloon occlusion with internal iliac artery balloon occlusion for patients with placenta accreta

BACKGROUND

The study was designed to compare the role of infrarenal aortic artery balloon occlusion (IAABC) with internal iliac artery balloon occlusion (IIABOC).

METHODS

One hundred seventy-four cases with placenta accreta were retrospectively analyzed.74 cases who had IAABC were in group A, while the others who had IIABOC were in group B.

RESULTS

Amount of estimated blood loss (EBL), the rate of major blood loss, the rate of blood transfusion and uterine packing, length of hospitalization were not different in both groups. The rate of uterine artery embolization (UAE), balloon occlusion time, operation time and fetus radiation dose in group A were less than those in group B.

CONCLUSIONS

IAABC resulted in better clinical outcomes than IIABOC.

Ovarian reserve after uterine artery embolization in women with morbidly adherent placenta: A cohort study

Objective

To evaluate ovarian reserve in women after preservative cesarean delivery using uterine artery embolization due to morbidly adherent placenta.

Study design

A historical cohort study including all women admitted to a single tertiary care center, with morbidly adherent placenta that had preservative cesarean delivery with bilateral uterine artery embolization. Inclusion criteria included gestational age >24 weeks, singleton pregnancy and placenta increta / percreta. Exclusion criteria included maternal age > 43 years old and cesarean hysterectomy. Control group included women attending the infertility clinic due to male factor or single women conceiving via sperm donation, matched by age. Blood samples were collected on day 2–5 of menstruations for hormonal profile and Anti Mullarian Hormone (AMH) levels. Primary outcome was ovarian reserve evaluated by the levels of AMH.

Results

59 women underwent preservative cesarean delivery using uterine artery embolization during the study period. 21 women met inclusion criteria (33.9%) and were matched controls (n = 40). Circulating levels of E2 and FSH did not differ significantly between the two groups (p = 0.665, p = 0.396, respectively). AMH was lower in the study group (median 0.8 IQR 0.44–1.80) compared to the controls (median 2.08 IQR 1.68–3.71) (p = 0.001). This finding was consistent in linear multivariate regression analysis where the group of cesarean delivery using bilateral artery embolization due to placenta accrete was significantly predictive for the levels of AMH (B = -1.308, p = 0.012).

Conclusion

Women post preservative cesarean delivery using uterine artery embolization due to placenta accrete have lower ovarian reserve compare to controls matched by age.

Resuscitative endovascular balloon occlusion of the aorta deployed by acute care surgeons in patients with morbidly adherent placenta: a feasible solution for two lives in peril

Morbidly adherent placenta (MAP), which includes accreta, increta, and percreta, is a condition characterized by the invasion of the uterine wall by placental tissue. The condition is associated with higher odds of massive post-partum hemorrhage. Several interventions have been developed to improve hemorrhage-related outcomes in these patients; however, there is no evidence to prefer any intervention over another. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an endovascular intervention that may be useful and effective to reduce hemorrhage and transfusions in MAP patients. The objective of this narrative review is to summarize the evidence for REBOA in patients with MAP. We posit that acute care surgeons can perform REBOA for patients with MAP.

Interobserver agreement and diagnostic performance of individual MRI criteria for diagnosis of placental adhesion disorders

AIM

To assess the diagnostic accuracy of several criteria for the diagnosis of placental adhesion disorder (PAD) on magnetic resonance imaging (MRI) and to assess interobserver agreement and reader accuracy based on years of interpretive experience.

MATERIALS AND METHODS

Blinded evaluation of the placental MRI studies of 28 randomly selected women, 18 with PADs and 10 without PADs, was undertaken by three radiologists with 10, 5, and 2 years' experience in placental MRI interpretation. The presence of placenta praevia, dark intraplacental bands, heterogeneity, uterine bulging, "shaggy dog" appearance of the uterine serosa, subjective impression of extraplacental invasion, and dark intraplacental bands on diffusion-weighted imaging were assessed. Placental histology was reviewed blinded to the original reports and to MRI interpretation and this, along with clinical information at the time of delivery, formed the reference standard.

RESULTS

Dark intraplacental bands on T2-weighted imaging were the most sensitive and specific as well as the most agreed upon (kappa=0.7) criterion for PAD for the three readers. Assessment of uterine bulging (kappa=0.42) and placental heterogeneity (kappa=0.48) did not improve diagnostic accuracy. DWI improved sensitivity but decreased specificity for the least experienced reader and did not change sensitivity or specificity for the more experienced readers.

CONCLUSION

Assessment of the placenta for dark bands is the most sensitive, specific, and reproducible criterion for diagnosis of PADs using MRI.

Clinical application of stage operation in patients with placenta accreta after previous caesarean section

To explore the clinical value of stage operation to patients with placenta accreta after previous caesarean section (CS).Nineteen women with medium and late pregnancies diagnosed with placenta accreta after previous CS were enrolled in this retrospective study and all underwent stage operation. Postpartum hemorrhage volume, red blood cells (RBC) transfusion, uterus retention rate, postpartum complications, and menstrual recovery were analyzed to evaluate the value of stage operation in patients with placenta accreta.Four of 19 cases were performed uterus curettage after 63, 38, 56, and 52 days of CS. Total hysterectomy was performed in 2 cases after 44 and 57 days of first-stage CS. Thirteen cases had placenta well discharged after treatment with the traditional Chinese medicine (TCM) Shenghua Decoction. The uterus retention rate was 89.48% (17/19). Mean postpartum hemorrhage volume was 1594.74 ± 1134.06 (400-4500) mL, mean volume of total hemorrhage was 1878.42 ± 1276.96 (400-4500) mL, mean RBC transfusion was 868.42 ± 816.53 (0.00-2400.00) mL. Postpartum bleeding volume showed≤1000 mL in 8 patients and ≤500 mL in 4 patients.Stage operation reduces postpartum hemorrhage volume and cesarean hysterectomy morbidity in patients with placenta accreta. However, infection and late postpartum hemorrhage should be monitored closely.

Serial Uterine Artery Embolization for the Treatment of Placenta Percreta in the First Trimester: A Case Report

Two patients with placenta percreta underwent uterine artery embolization (UAE) for abnormally invasive placenta (AIP) in the first trimester. Patient 1 had a 9-week cervical ectopic, while Patient 2 had a 9-week cesarean scar pregnancy. Elective termination of pregnancy was performed in both patients. UAE was performed with tris-acryl gelatin microspheres as well as gelfoam until stasis and was repeated in cases of revascularization. Both patients were followed with US/MRI/MRA scans and β-hCG levels. Revascularization occurred in both patients following UAE, requiring multiple embolizations to achieve complete placental involution. Serial bland UAE may be an effective technique in the treatment of first-trimester AIP, with the distinct advantage of maintaining a patient's fertility.

LEVEL OF EVIDENCE

Level IV.

The diagnosis and management of morbidly adherent placenta

The incidence of morbidly adherent placenta (MAP) has risen 13-fold since the early 1900s and is directly correlated with the rising rate of cesarean delivery. It is important for clinicians to screen all pregnancies for MAP at the time of routine second-trimester ultrasonography. In addition, patients with risk factors (e.g., multiple prior cesarean deliveries) should undergo targeted screening for MAP. Optimal maternal and fetal outcomes for these high-risk pregnancies result from accurate prenatal diagnosis and comprehensive multidisciplinary preparation and delivery between 34 and 36 weeks of gestation. There continue to be large knowledge gaps with respect to the optimal management of this condition especially around diagnosis, obstetric care, timing of delivery, and surgical management. Accordingly, most recommendations are based on expert opinion rather than on high-quality evidence. Prospective clinical trials are needed to address knowledge gaps and to continue to improve outcomes.

Ultrasonographic criteria of cesarean scar defect evaluation

Cesarean sections account for approximately 20% of all deliveries worldwide. In Poland, the percentage of women delivering by cesarean section amounts to over 43%. According to studies, the prevalence of cesarean scar defects ranges from 24-70%. Due to the overall cesarean section rate, this is a medical problem affecting a large population of women. In such cases, ultrasonographic evaluation of a cesarean scar reveals a hypoechoic space filled with postmenstrual blood, representing a myometrial tear at the wound site. Such an ultrasound appearance is referred to as a niche, and it forms after a cesarean section at the site of the hysterotomy of the anterior uterine wall, most commonly within the uterine isthmus. Currently, the exact cause of niche formation remains unexplained, yet the risk factors for its development are universally acknowledged. They include the site of hysterotomy, multiple previous cesarean section deliveries, suturing technique and maternal diabetes or smoking. Ultrasound evaluation of the cesarean section scar is an important element of obstetric and gynecologic practice, especially in the case of further pregnancies. It facilitates an early diagnosis of a cesarean scar ectopic pregnancy, and the prediction of the risk for perinatal dehiscence in the case of a vaginal birth after a cesarean section.

Placental pathologic changes and perinatal outcomes in placenta previa

INTRODUCTION

Placenta previa is a condition in which the placenta implants in the poorly vascularized lower uterine segment, which may result in inadequate uteroplacental perfusion, in turn, adversely affect the neonatal outcome. Abnormal placentation may also lead to severe postpartum hemorrhage as placenta separation proceeds. We aimed to evaluate the differences in placental histopathology and perinatal outcomes in pregnancies complicated with placenta previa and controls.

METHOD

We undertook a retrospective case-control study of 93 pregnancies with placenta previa and 81 controls between 2011 and 2017.

RESULTS

Gross findings of the placenta showed that the placentas in placenta previa had significantly higher mean large chorionic plate diameters (18.5 ± 3.2 vs 17.5 ± 2.6 cm, P = .0298), chorionic plate areas (218.4 ± 62.9 cm² vs 198.7 ± 56.0 cm², P = .0344), and marginal cord insertion (19.8% vs 8.6%, P = .0411) than control groups. Placental histopathological findings showed that placentas in placenta previa was significantly associated with maternal underperfusion, including villous infarction (50.5% vs 25.9%, P = .0009) and increased intervillous fibrin deposition (38.7% vs 7.4%, P < .0001). Also, women in the placenta previa group had a higher rate of abnormally invasive placenta and severe postpartum hemorrhage. However, placenta previa was not associated with the increased risk of neonatal mortality and morbidity.

DISCUSSION

Abnormal placentation into the poorly vascularized lower uterine segment induces compensatory placental growth and increased surface area in response to reduced placental perfusion, which was consistent with the histopathological findings of coagulative necrosis of chorionic villi and fibrin deposition in the intervillous space. The morphological changes occurring in placenta previa may have important roles in maintaining adequate uteroplacental-fetal perfusion, which may prevent adverse neonatal outcomes.

Prophylactic temporary abdominal aorta balloon occlusion in women with placenta previa accretism during late gestation

BACKGROUND

To evaluate the clinical efficacy of prophylactic temporary balloon occlusion of the abdominal aorta in patients with placenta previa accretism during cesarean section.

METHODS

Twenty-three consecutive patients, prenatally confirmed with placenta previa accretism were retrospectively analyzed in our center from August 2012 to October 2014. All 23 subjects underwent cesarean section with prophylactic balloon occlusion of the abdominal aorta.

RESULTS

All of the 23 subjects experienced singleton pregnancies leading to the birth of live infants. Of these subjects, the following problems were diagnosed: placenta accrete (n = 10), placenta increte (n = 10), and placenta precrete (n = 3). Mean intraoperative hemorrhage was 1170.0 mL. Fifteen patients received red blood cell transfusion with a mean transfusion volume of 2.3 units. The incidence of hysterectomy was 21.74% (5/23) with blood loss ranging from 2000 to 5000 mL (mean 3360.0 mL). One complication encountered in this retrospective study was lower extremity arterial thrombosis. Eighteen patients were followed-up by telephone to 14 months following discharge, all babies were noted to be healthy.

CONCLUSION

Prophylactic abdominal aorta balloon occlusion (ABO) was relatively safe in the treatment of patients with placenta previa accretism. This approach could represent a key aspect in a multidisciplinary algorithm in reducing hemorrhage in abnormal placentation.

Increased rates of cesarean sections and large families: a potentially dangerous combination

Rates of cesarean sections have been on the rise over the past three decades all over the world, despite the ideal rate of 10-15% that had been set by the World Health Organization (WHO) in 1985, in Fortaleza, Brazil. This epidemic increase in the rate of cesarean delivery is due to many factors which include, cesarean delivery on request, advanced maternal age at first pregnancy, decrease in number of patients who are willing to try vaginal birth after cesarean delivery, virtual disappearance of vaginal breech delivery, perceived increase in the weight of the fetus and increase in the number of women with chronic medical conditions such as Diabetes Mellitus and congenital heart disease in the reproductive age. There is no doubt that cesarean delivery is a safe procedure and it is getting safer and safer for many reasons. However, like all other surgical procedures it is not without risks both to the mother and the new born. There is a substantial increase in the incidence of morbidly adherent placenta and the risk of scar pregnancy. In the Middle East and many African and Asian countries women tend to have large families. The number of previous cesarean section deliveries is directly proportional to the risk of developing morbidly adherent placenta. Morbidly adherent placenta is the most common cause of emergency postpartum hysterectomy, which is often associated with multiple surgical complications, severe maternal morbidity and mortality. The increased rates of cesarean sections lead to increased rates of scar pregnancies, which can have lethal consequences. Cesarean delivery has a negative impact on the infant immune system. This effect on the infant led to the introduction of a new concept called "Vaginal seeding". This refers to the practice of transferring some maternal vaginal fluid to the infant born via cesarean section in an effort to enhance its immune system.

Intrauterine Inflated Foley's Catheter Balloon in the Management of Abnormally Invasive Placenta Previa: A Case-Control Study

Objective

To describe the use of intrauterine inflated Foley's catheter balloon for control of postpartum hemorrhage (PPH) during cesarean section (CS) in cases of abnormally invasive placenta previa aiming to preserve the uterus.

Methods

Retrospective case-control study of the data of women who underwent elective CS on abnormally adherent placenta previa was carried out. Women in whom inflated Foley's catheter balloon was used for control of PPH during CS (n = 40) were compared with a control group of women who underwent elective CS by the same technique but without use of intrauterine catheter balloon (n = 38).

Results

Use of intrauterine inflated Foley's catheter balloon significantly reduced the estimated amount of blood loss (P = 0.008), amounts of crystalloids, colloids and packed red blood cells transfusion (P = 0.025, 0.017 and 0.022, respectively), and the need for bilateral internal iliac artery (IIA) ligation (P = 0.016). No significant difference was observed between both groups regarding the use of massive transfusion protocol, performing cesarean hysterectomy, relaparotomy, and admission to the intensive care unit.

Conclusion

Application of an intrauterine inflated Foley's catheter balloon during CS in cases of morbidly adherent placenta previa helps to control PPH with preservation of the uterus and decreases the need for the invasive IIA ligation.

Confirmation of posterior uterine rupture in the second trimester by magnetic resonance imaging

Intrapartum uterine rupture is a life-threating and rare complication of pregnancy which seldom occurs in the second trimester. Typically, the diagnosis is made using ultrasound; however, magnetic resonance imaging can provide certain advantages in the emergent setting. We present a unique case of a posterior uterine rupture confirmed by magnetic resonance imaging involving the unscarred posterior uterine wall in a 20-year-old gravid female with two previous cesarean-sections.

Uterine Artery Embolization for Management of Primary Postpartum Hemorrhage Associated with Placenta Accreta

Objective To evaluate the efficacy and safety of uterine artery embolization (UAE) in the management of primary postpartum hemorrhage associated with placenta accreta. Methods We retrospectively reviewed the medical records of patients with placenta accreta between January 2010 and August 2014. Totally 18 women (mean age 30.8±4.2 years) of primary massive postpartum hemorrhage with diagnosis of placenta accrete received treatment of UAE after delivery. Images of DSA and medical records were reviewed. Technical success was defined as control of bleeding after embolization. The complications, control of hemorrhage and recurrent bleeding of the placenta left inside the uterus were retrospectively collected for assessment. Results All patients underwent transcatheter embolization of bilateral uterine arteries. The technical success rate of embolization was 100%. Bleeding was controlled in 17 of 18 patients (94%) during follow-up period (median 18 months, 3-31months) without further bleeding recurred. One patient with placenta percreta undertook an emergent hysterectomy along with surgical bladder repair after UAE because of persistent uterine bleeding. Eight patients had postembolization syndrome and no other complications occurred. Conclusion Uterine artery embolization is an effective and safe treatment for the management of primary postpartum massive hemorrhage associated with placenta accreta.

Extracellular matrix proteins in healthy and retained placentas, comparing hemochorial and synepitheliochorial placentas

The placenta expresses structural and biologically active proteins. Their synthesis is mainly regulated by genomic or nongenomic signals and modulated by hormones. These protein profiles are altered during different stages of pregnancy. The biological properties of extracellular matrix (ECM) proteins were defined and described in a number of tissues including placenta. These properties enable them to be the main players in the processes of attachment or invasion into the endometrium during initial placenta formation and its timely separation after delivery and detachment. In this review, we focused on the role of ECM proteins during attachment of the placenta to the uterine wall, its timely separation, and the implications of this process on retained or pathologically attached placenta. Although the amount of published information in this area is relatively scant, some of the key proteins and processes are well defined. We focused on the available data detailing the ECM protein profiles of human (histologically thin; hemochorial) and bovine (histologically thick; epitheliochorial) placentas and compared the shared and unique ECM proteins that are relevant to placental attachment and separation.

Prediction of morbidly adherent placenta using a scoring system

OBJECTIVE

To evaluate the accuracy of an ultrasound-based scoring system for diagnosing morbidly adherent placenta (MAP).

METHODS

This study included pregnant women referred to our ultrasound unit during 2013-2015 because of suspected MAP on a previous ultrasound examination or because they had at least one previous Cesarean delivery. All women were assessed using a scoring system based on the following: number and size of placental lacunae; obliteration of the demarcation between the uterus and placenta; placental location; color Doppler signals within placental lacunae; hypervascularity of the placenta-bladder and/or uteroplacental interface zone; and number of previous Cesarean deliveries. Each criterion was assigned 0, 1 or 2 points and the sum of points yielded the final score. Patients were classified into low, moderate or high probability for MAP based on the final score. The presence of MAP was determined by the surgeon at delivery and clinical descriptions were documented in the electronic patient file. Pathological diagnoses were available only in cases that underwent hysterectomy.

RESULTS

In total, 258 pregnant women were included in the study, of whom 23 (8.9%) were diagnosed with MAP. There was a statistically significant difference in the prevalence of MAP when women were grouped according to the scoring system, with 0.9%, 29.4% and 84.2% in the low, moderate and high probability groups, respectively (P < 0.0001). All sonographic criteria of the scoring system were significantly associated with MAP (P < 0.0001). Receiver-operating characteristics (ROC) curves for prediction of MAP using the number of placental lacunae and obliteration of the uteroplacental demarcation yielded an area under the ROC curve of 0.94 (95% CI, 0.86-1.00).

CONCLUSIONS

Our proposed scoring system is highly predictive of MAP in patients at risk. This allows an adequate multidisciplinary team approach for the planning and timing of delivery in such cases. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Morbidly Adherent Placenta: Its Management and Maternal and Perinatal Outcome

OBJECTIVES

The aim of the study was to identify the risk factors predisposing to morbidly adherent placenta and to study the different modes of management and the obstetric and neonatal outcome of these patients.

METHODS

This was a retrospective cum prospective observational study conducted in the Department of Obstetrics and Gynaecology in a tertiary care referral hospital in Mumbai from January 2012 to November 2014.

RESULTS

The incidence of morbidly adherent placenta was 1.32 per 1000 pregnancies with patient profile comprising second gravida in the age group 26-28 years; 90 % of the patients in this study had previous Caesarean section and co-existing placenta praevia was diagnosed in 63 %. Fifty-three per cent of the women delivered between 35 and 38 weeks and 40 % had elective deliveries. Caesarean section was the mode of delivery in 90 % of the patients. Prophylactic balloon placement in the internal iliac artery followed by classical Caesarean section, uterine artery embolization and post-operative methotrexate was done in 27 % which preserved the uterus and was associated the blood loss of 1000-2000 mL.

CONCLUSION

Antenatal diagnosis of morbidly adherent placenta allows for multidisciplinary planning in an attempt to minimize potential maternal or neonatal morbidity and mortality.

Abnormal Placentation: Placenta Previa, Vasa Previa, and Placenta Accreta

Placental disorders such as placenta previa, placenta accreta, and vasa previa are all associated with vaginal bleeding in the second half of pregnancy. They are also important causes of serious fetal and maternal morbidity and even mortality. Moreover, the rates of previa and accreta are increasing, probably as a result of increasing rates of cesarean delivery, maternal age, and assisted reproductive technology. The routine use of obstetric ultrasonography as well as improving ultrasonographic technology allows for the antenatal diagnosis of these conditions. In turn, antenatal diagnosis facilitates optimal obstetric management. This review emphasizes an evidence-based approach to the clinical management of pregnancies with these conditions as well as highlights important knowledge gaps.

Accuracy of three-dimensional multislice view Doppler in diagnosis of morbid adherent placenta

OBJECTIVE

To detect the accuracy of the three-dimensional multislice view (3D MSV) Doppler in the diagnosis of morbid adherent placenta (MAP).

MATERIAL AND METHODS

Fifty pregnant women at ≥28 weeks gestation with suspected MAP were included in this prospective study. Two dimensional (2D) trans-abdominal gray-scale ultrasound scan was performed for the subjects to confirm the gestational age, placental location, and findings suggestive of MAP, followed by the 3D power Doppler and then the 3D MSV Doppler to confirm the diagnosis of MAP. Intraoperative findings and histopathology results of removed uteri in cases managed by emergency hysterectomy were compared with preoperative sonographic findings to detect the accuracy of the 3D MSV Doppler in the diagnosis of MAP.

RESULTS

The 3D MSV Doppler increased the accuracy and predictive values of the diagnostic criteria of MAP compared with the 3D power Doppler. The sensitivity and negative predictive value (NPV) (79.6% and 82.2%, respectively) of crowded vessels over the peripheral sub-placental zone to detect difficult placental separation and considerable intraoperative blood loss in cases of MAP using the 3D power Doppler was increased to 82.6% and 84%, respectively, using the 3D MSV Doppler. In addition, the sensitivity, specificity, and positive predictive value (PPV) (90.9%, 68.8%, and 47%, respectively) of the disruption of the uterine serosa-bladder interface for the detection of emergency hysterectomy in cases of MAP using the 3D power Doppler was increased to 100%, 71.8%, and 50%, respectively, using the 3D MSV Doppler.

CONCLUSION

The 3D MSV Doppler is a useful adjunctive tool to the 3D power Doppler or color Doppler to refine the diagnosis of MAP.

A standardized approach for the assessment of the lower uterine segment at first trimester by transvaginal ultrasound: a flash study

OBJECTIVES

To evaluate the reproducibility of a standardized approach to lower uterine segment (LUS) imaging by transvaginal ultrasound at 11-14 weeks.

METHODS

This was a "flash" study lasting for 1 month. Obstetrician-sonographers performing more than 50 first trimester ultrasounds per year participated. All consecutive women attending for their 11-14 weeks scan were included. A standardized, transvaginal approach to the imaging of LUS was defined. The sonographers recorded one or two images of the LUS. The quality of the images was assessed by sonographers and reviewed by an independent fetal medicine specialist using the same scoring system. Inter and intra-reviewer variability was assessed.

RESULTS

Seventy-one sonographers and 851 pregnant women participated. The mean (±SD) and medium (IQR) scores attributed by sonographer versus reviewer were 5.01 (±0.92) and 5 [4-6] versus 4.68 (±1.14) and 5 [4-5.24], p = 0.08. The mean [95% CI] difference of -0.33 [-2.6;2] was recorded. There was good, moderate and poor agreement in 74.4%, 16.7% and 8.9% cases, respectively. Variability in inter-reviewer and intra-reviewer was low with the mean [95% CI] difference of -0.1 [-1.6;1.4] and -0.1 [-1.4;1.2] respectively.

CONCLUSIONS

A standardized approach to LUS imaging at 11-14 weeks is feasible and highly reproducible in a large population.

Predictors of severity in primary postpartum hemorrhage

PURPOSE

To identify risk factors and etiologies leading to severe primary postpartum hemorrhage (PPH) in women with PPH.

METHODS

Women who experienced PPH within the first 24 h after delivery over a 3-year period were retrospectively evaluated. Patients were divided into two groups on the basis of severe PPH (n = 125) or non-severe PPH (n = 411). Risk factors and etiologies for severe PPH were explored using univariate and multivariate logistic regression analyses.

RESULTS

PPH and severe PPH complicated 2.1 and 0.49 % of all deliveries, respectively. Previous cesarean delivery (OR = 3.15, 95 % CI = 1.02-10.3; p = 0.001), prolonged labor (OR = 3.62, 95 % CI = 3.21-4.03; p < 0.001), oxytocin augmentation (OR = 3.32, 95 % CI 2.05-5.93; p < 0.001) and emergency cesarean delivery (OR = 4.75, 95 % CI 1.32-12.96; p < 0.001) were the factors independently associated with severe PPH. Etiologies significantly associated with severe PPH are uterine atony (OR = 2.72, 95 % CI 1.64-4.55; p < 0.001) and abnormal placentation (OR = 3.05, 95 % CI 1.56-6.27; p = 0.006).

CONCLUSION

Previous cesarean delivery, prolonged labor, oxytocin augmentation and emergency cesarean delivery are strongest predictors of severe blood loss in women with PPH. In addition, uterine atony and abnormal placentation are the etiologies significantly associated with severe PPH.

Conservative Management of Invasive Placenta Using Combined Prophylactic Internal Iliac Artery Balloon Occlusion and Immediate Postoperative Uterine Artery Embolization

Purpose

The objective of the study was to evaluate the efficacy and safety of combined prophylactic intraoperative internal iliac artery balloon occlusion and postoperative uterine artery embolization in the conservative management (uterine preservation) of women with invasive placenta undergoing scheduled caesarean delivery.

Methods

Ten women (mean age 35 years) with invasive placenta choosing caesarean delivery without hysterectomy had preoperative insertion of internal iliac artery occlusion balloons, intraoperative inflation of the balloons, and immediate postoperative uterine artery embolization with absorbable gelatin sponge. A retrospective review was performed with institutional review board approval. Outcome measures were intraoperative blood loss, transfusion requirement, hysterectomy rate, endovascular complications, surgical complications, and postoperative morbidity.

Results

All women had placenta increta or percreta, and concomitant complete placenta previa. Mean gestational age at delivery was 36 weeks. In 6 women the placenta was left undisturbed in the uterus, 2 had partial removal of the placenta, and 2 had piecemeal removal of the whole placenta. Mean estimated blood loss during caesarean delivery was 1.2 L. Only 2 patients (20%) required blood transfusion. There were no intraoperative surgical complications, endovascular complications, maternal deaths, or perinatal deaths. Three women developed postpartum complications necessitating postpartum hysterectomy; the hysterectomy rate was therefore 30% and uterine preservation was successful in 70%.

Conclusion

Combined bilateral internal iliac artery balloon occlusion and uterine artery embolization may be an effective strategy to control intraoperative blood loss and preserve the uterus in patients with invasive placenta undergoing caesarean delivery.

Placenta accreta: adherent placenta due to Asherman syndrome

It is important to be aware of the risk of abnormally invasive placenta in patients with a history of Asherman syndrome and uterine scarring. A prenatal diagnosis by ultrasonography is useful when planning of mode of delivery.

Interobserver variability of sonography for prediction of placenta accreta

OBJECTIVES

The sensitivity of sonography to predict accreta has been reported as higher than 90%. However, most studies are from single expert investigators. Our objective was to analyze interobserver variability of sonography for prediction of placenta accreta.

METHODS

Patients with previa with and without accreta were ascertained, and images with placental views were collected, deidentified, and placed in random sequence. Three radiologists and 3 maternal-fetal medicine specialists interpreted each study for the presence of accreta and specific findings reported to be associated with its diagnosis. Investigator-specific sensitivity, specificity, and accuracy were calculated. κ statistics were used to assess variability between individuals and types of investigators.

RESULTS

A total of 229 sonographic studies from 55 patients with accreta and 56 control patients were examined. Accuracy ranged from 55.9% to 76.4%. Of imaging studies yielding diagnoses, sensitivity ranged from 53.4% to 74.4%, and specificity ranged from 70.8% to 94.8%. Overall interobserver agreement was moderate (mean κ ± SD = 0.47 ± 0.12). κ values between pairs of investigators ranged from 0.32 (fair agreement) to 0.73 (substantial agreement). Average individual agreement ranged from fair (κ = 0.35) to moderate (κ = 0.53).

CONCLUSIONS

Blinded from clinical data, sonography has significant interobserver variability for the diagnosis of placenta accreta.