Predisposing factors for massive hemorrhage during Cesarean section in patients with placenta previa

Prediction of hemorrhage in placenta previa: Radiomics analysis of pelvic MRI images

INTRODUCTION

Prediction of intraoperative massive hemorrhage is still challenging in placenta previa. Radiomics analysis has been investigated as a new evaluation method for analyzing medical images. We used radiomics analysis on placental magnetic resonance imaging (MRI) images to predict intraoperative hemorrhage in placenta previa.

METHODS

We used the sagittal MRI T2-weighted sequence in placenta previa. Using the rectangular region from the uterine os to the anterior wall, we extracted 97 radiomics features. We also collected patient demographics and blood test data as clinical variables. Combining these radiomics features and clinical variables, logistic regression models with a stepwise method were built to predict the risk of hemorrhage, defined as blood loss of > 2000 ml. We evaluated the prediction performance of the models using accuracy and area under the curve (AUC), also analyzing the important variables for the prediction by stepwise methods.

RESULTS

We enrolled a total of 63 placenta previa cases including 30 hemorrhage cases from two institutes. The model combining clinical variables and radiomics features showed the best prediction performance with an accuracy of 0.70 and an AUC of 0.69 in the internal validation data, and accuracy of 0.41 and an AUC of 0.70 in the external validation data, compared with human experts (accuracy of 0.62). Regarding variable selection, two radiomics features. 'original_glrlm_LowGrayLevelRunEmphasis,' and 'diagnostics_Image-original_Minimum,' were important predictors for hemorrhage by the stepwise method.

DISCUSSION

Radiomics features based on MRI could be used as effective predictive variables for hemorrhage in placenta previa. Radiomics analysis of placental imaging could lead to further analysis of quantitative variables related to obstetric diseases.

Sonographic Predictors of Antepartum Bleeding in Placenta Previa

OBJECTIVE

To evaluate the association between sonographic features of placenta previa and vaginal bleeding (VB).

STUDY DESIGN

Retrospective cohort study of women with placenta previa identified on ultrasound between 160/7 and 276/7 weeks gestation. Placental distance past the cervical os (DPO), placental thickness, edge angle, and cervical length (CL) were measured. The primary outcome was any VB and the secondary outcome was VB requiring delivery. Median values of the sonographic features were compared for each of the outcomes using the Mann-Whitney U test. Receiver operating characteristic curves were used to compare the predictive value of sonographic variables markers and to determine optimal cut points for each measurement. Logistic regression was used to estimate the association between each measure and the outcomes while controlling for confounders.

RESULTS

Of 149 women with placenta previa, 37% had VB and 15% had VB requiring delivery. Women with VB requiring delivery had significantly more episodes of VB than those who did not require delivery for VB (1.5, interquartile range [IQR] [1-3] vs 1.0 [1-5]; p = 0.001). In univariate analysis, women with VB had decreased CL (3.9 vs. 4.2 cm; p < 0.01) compared with those without. Women with VB requiring delivery had increased DPO (2.6 cm IQR [1.7-3.3] vs. 1.5 cm [1.1-2.4], p = 0.01) compared with those without. After adjusting for confounders, only CL < 4 cm remained independently associated with increased risk of VB (adjusted odds ratio: 2.27, 95% confidence interval [1.12-4.58], p = 0.01). None of the measures were predictive of either outcome (area under the curve < 0.65).

CONCLUSION

Decreased CL may be associated with risk of VB in placenta previa.

KEY POINTS

· Placenta previa is associated with VB.. · Sonographic markers of placenta previa are associated with VB.. · CL is associated with VB in placenta previa, whereas placental DPO is associated with higher rates of bleeding leading to delivery..

Evaluation of maternal serum VEGF, TNF-alpha, IL-4, and IL-10 levels in differentiating placenta accreta spectrum from isolated placenta previa

OBJECTIVE

Our study aimed to differentiate patients with placenta accreta spectrum (PAS) from those with placenta previa (PP) using maternal serum levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4), and IL-10.

METHODS

The case group consisted of 77 patients with placenta previa, and the control group consisted of 90 non-previa pregnant women. Of the pregnant women in the case group, 40 were diagnosed with PAS in addition to placenta previa and 37 had placenta previa with no invasion. The maternal serum VEGF, TNF-alpha, IL-4, and IL-10 levels were compared between the case and control groups. Then the success of these markers in differentiating between PP and PAS was evaluated.

RESULTS

We found the VEGF, TNF-alpha, and IL-4 levels to be higher and the IL-10 level to be lower in the case group compared to the control group (p < 0.001). We observed a statistically significantly lower IL-10 level in the patients with PAS than those with PP (p = 0.029). In the receiver operating characteristic analysis, the optimal cut-off of IL-10 in the detection of PAS was 0.42 ng/mL). In multivariate analysis, the risk of PAS was significant for IL-10 (odds ratio (OR) 0.45, 95 % confidence interval (CI) 0.25-0.79, p = 0.006) and previous cesarean section (OR 2.50, 95 % Cl 1.34-4.66, p = 0.004). The model's diagnostic sensitivity and specificity, including previous cesarean section, preoperative hemoglobin (Hb), TNF-alpha, and IL-10 were 75 % and 72.9 %, respectively.

CONCLUSION

The study showed that the IL-10 level was lower in patients with PAS than in those with PP. A statistical model combining risk factors including previous cesarean section, preoperative Hb, TNF-alpha, and IL-10 may improve clinical diagnosis of PAS in placenta previa cases. Cytokines may be used as additional biomarkers to the clinical risk factors in the diagnosis of PAS.

Utility of the angle between the cervical canal and the anatomical conjugate line for predicting pouch of Douglas obliteration in patients with posterior placenta previa

AIM

Pouch of Douglas obliteration, which prevents exteriorization of the uterus, increases surgical morbidity in patients with placenta previa. We aimed to identify magnetic resonance imaging features that can predict pouch of Douglas obliteration preoperatively.

METHODS

We retrospectively assessed 39 women with posterior placenta previa who underwent magnetic resonance imaging for the preoperative assessment of placenta accreta spectrum. We defined the angle formed by the anatomical conjugate line (based on pelvimetry) and the cervical canal as the cervical inclination angle, which was measured on sagittal T2-weighted magnetic resonance imaging. Subsequently, we analyzed the correlation between the cervical inclination angle and pouch of Douglas obliteration.

RESULTS

The median maternal age was 34 years (range, 22-44 years) and 26 (66.7%) women delivered at term. The median cervical inclination angle was 98° (range, 71-128). Pouch of Douglas obliteration was confirmed in six patients (15.4%). The cut-off value of the cervical inclination angle for the prediction of pouch of Douglas obliteration was 102° with a sensitivity of 66.7%, specificity of 78.8%, positive predictive value of 36.4%, and negative predictive value of 92.9% (area under the curve, 0.83).

CONCLUSIONS

Measuring the cervical inclination angle may help in ruling out an obliteration of the pouch of Douglas. It may also be useful in the operative management of women with posterior placenta previa. However, caution should be exercised when generalizing the results of this study because of the small sample size, which makes the results prone to bias.

Desenlaces maternos según el tipo de placenta previa en un hospital de alta complejidad en Cali, Colombia. Estudio de cohorte retrospectivo

Objetivos: describir la frecuencia de complicaciones maternas en mujeres gestantes con placenta previa (PP) mayor o menor y evaluar una posible de asociación entre tipo de PP y la presencia de hemorragia materna severa y otros resultados maternos asociados. Materiales y métodos: cohorte retrospectiva, descriptiva. Se incluyeron gestantes con 20 semanas o más de embarazo, con diagnóstico confirmado de placenta previa, quienes fueron atendidas en un hospital de alto nivel de complejidad localizado en Cali (Colombia), entre enero de 2011 y diciembre de 2020. Se excluyeron las gestantes con diagnóstico de placenta previa y acretismo placentario concomitante. Las variables recolectadas fueron: edad materna, índice de masa corporal, tabaquismo, obesidad, paridad, presencia de sangrado, hemorragia posparto, manejo de la hemorragia posparto, transfusión y admisión a UCI de la gestante. Se realizó análisis descriptivo. El protocolo fue aprobado por el comité de ética de la Fundación Valle de Lili. Resultados: 146 pacientes cumplieron con los criterios de inclusión. La población estuvo constituida por mujeres con una mediana de edad de 32 años, sin antecedente quirúrgico, con diagnóstico prenatal de placenta previa a la semana 22. En el 70,5 % de los casos se trató de pacientes con placenta previa mayor. Las complicaciones más frecuentes fueron hemorragia posparto (37,9 % vs. 16,3 % para pacientes con placenta previa mayor y menor, respectivamente), requerimiento de transfusión (23,3 y 9,3 %, respectivamente) y el ingreso materno a la UCI (40,8 % vs. 18,6 %, respectivamente). No se registraron muertes maternas. Conclusiones: las mujeres con placenta previa experimentan una frecuencia elevada de complicaciones; probablemente, dicha frecuencia es más alta cuando se documenta placenta previa mayor. Se requieren más estudios que comparen la frecuencia de complicaciones maternas según el tipo de placenta previa.

Bleeding-related outcomes of low-risk total placenta previa are equivalent to those of partial/marginal placenta previa

OBJECTIVE

To clarify whether "low-risk total PP" patients bleed more than partial/marginal PP patients.

MATERIALS AND METHODS

The retrospective cohort study was performed involving patients with PP between April 2006 and December 2018. The placental position was determined by ultrasound. From medical charts, the backgrounds as well as obstetric and neonatal outcomes of PP patients were retrieved.

RESULTS

This study included 349 patients with PP, which was classified into three types according to the distance between the placenta and internal ostium: total (n = 174), partial (n = 52), and marginal (n = 123) PP. In total PP patients, three factors (prior CS, anterior placenta, and placental lacunae on ultrasound) significantly increased blood loss at CS, the need for hysterectomy, homologous transfusion (≥10 U), and ICU admission. No significant difference was observed in bleeding-related poor outcomes (rate of blood loss ≥2000 mL, amount of homologous transfusion, need for hysterectomy, and ICU admission) between total PP patients without all three factors: "low-risk total PP patients" and partial/marginal PP patients (19.8 vs. 17.1%; p = 0.604, 3.7 vs. 1.1%; p = 0.330, 1.2 vs. 1.1%; p = 1.000, and 1.2 vs. 1.1%; p = 1.000, respectively).

CONCLUSION

Prior CS, anterior placenta, and placental lacunae on ultrasound were risk factors for a bleeding-related poor outcome in total PP patients. Total PP patients without these three factors showed the same bleeding-related poor outcome as partial/marginal PP patients.

The Feasibility and Safety of Temporary Transcatheter Balloon Occlusion of Bilateral Internal Iliac Arteries during Cesarean Section in a Hybrid Operating Room for Placenta Previa with a High Risk of Massive Hemorrhage

This study aimed to evaluate the feasibility and safety of temporary transcatheter balloon occlusion of bilateral internal iliac arteries (TBOIIA) during cesarean section in a hybrid operating room (OR) for placenta previa (PP) with a high risk of massive hemorrhage. This retrospective study analyzed the medical records of 62 patients experiencing PP with a high risk of massive hemorrhage (mean age, 36.2 years; age range 28-45 years) who delivered a baby via planned cesarean section with TBOIIA in a hybrid OR between May 2019 and July 2021. Operation time, estimated blood loss (EBL), amount of intra- and postoperative blood transfusion, perioperative hemoglobin level, hospital stay after operation, balloon time, fluoroscopy time, radiation dose, rate of uterine artery embolization (UAE) and hysterectomy, and complication-related TBOIIA were assessed. The mean operation time was 122 min, and EBL was 1290 mL. Nine out of sixty-two patients (14.5%) received a blood transfusion. The mean hemoglobin levels before surgery, immediately after surgery and within 1 week after surgery were 11.3 g/dL, 10.4 g/dL and 9.2 g/dL, respectively. In terms of radiation dose, the mean dose area product (DAP) and cumulative air kerma were 0.017 Gy/cm² and 0.023 Gy, respectively. Ten out of sixty-two patients (16.1%) underwent UAE postoperatively in the hybrid OR. One out of sixty-two patients had been diagnosed with placenta percreta with bladder invasion based on preoperative ultrasound, and thus underwent cesarean hysterectomy following TBOIIA and UAE. While intra-arterial balloon catheter placement for managing PP with a high risk of hemorrhage remains controversial, a planned cesarean section with TBOIIA in a hybrid OR is effective in eliminating the potential risk of intra-arterial balloon catheter displacement, thus reducing intraoperative blood loss, ensuring safe placental removal and conserving the uterus.

Hemostatic effect of combined procedures for placenta previa: cervix-holding, intrauterine balloon, and uterine compression suture

OBJECTIVES

Various procedures have been introduced to achieve hemostasis for postpartum hemorrhage (PPH) in placenta previa (PP). This study attempted to clarify the effectiveness of the combined use of three hemostatic procedures: Matsubara-Takahashi cervix-holding (MT-holding), intrauterine balloon (IUB), and uterine compression suture (UCS).

STUDY DESIGN

This was a historical cohort study on the hemostatic effect of combined procedures for patients with placenta previa (PP) undergoing cesarean section between April 2006 and December 2018. Until 2011 (2006-2011), we used MT-holding alone, whereas since 2012 we have also been using IUB and UCS: MT-holding alone was used in the former period whereas three procedures (MT-holding, IUB, UCS, and their combinations) have been used in the latter period. Perinatal outcomes were compared between 2006-2011 (before group) and 2012-2018 (after group).

RESULTS

Of 416 patients with PP, excluding 273 patients with cesarean hysterectomy or no hemostatic procedure, the remaining 143 patients were analyzed. In the after group, intraoperative blood loss, the percentage of patients with postoperative blood loss ≥ 500 ml, and incidence of autologous blood transfusion were significantly lower than in the before group. Multivariate analysis showed that postoperative blood loss ≥ 500 ml decreased in the after group (adjusted OR: 0.3, 95%CI: 0.1-0.8, compared with the before group).

CONCLUSION

PPH decreased after introducing the combination of hemostatic procedures in patients with PP. Further studies are needed to determine the best combination and optimal indication for combining hemostatic procedures for PP.

Criteria for placenta accreta spectrum in the International Federation of Gynaecology and Obstetrics classification, and topographic invasion area are associated with massive hemorrhage in patients with placenta previa

INTRODUCTION

Placenta previa with placenta accreta spectrum (PAS) is a life-threatening disease that results in massive hemorrhage. The clinical and histologic criteria of PAS were adopted according to the International Federation of Gynaecology and Obstetrics (FIGO) classification. We aimed to investigate whether FIGO criteria and topography were associated with maternal complications in patients with placenta previa.

MATERIAL AND METHODS

Patients with placenta previa who underwent cesarean section at our institution between January 2003 and December 2019 were identified. First, they were divided based on FIGO classification, as follows: Group A, with clinical criteria; Group B, with histologic criteria; and Group C: without clinical or histologic criteria. Next, cases with PAS were classified according to the topographic invasion area, as follows: type 1, upper posterior bladder; type 2, lower posterior bladder; type 3, parametrium; type 4, posterior lower uterine segment. Predictive factors for massive hemorrhage were retrospectively analyzed.

RESULTS

Among the 350 patients, 24 (6.9%) were classified as Group A, 16 (4.6%) as Group B and 310 (88.5%) as Group C. Regarding maternal history and hemostatic procedures, there were no significant factors other than hysterectomy (p < .01) in Groups A and B. The volume of blood loss in both Groups A and B was greater than in Group C (p < .01). The rates of uterine artery embolization and blood transfusion were higher in Groups A and B than in Group C (p < .01). In addition, there were no significant factors other than hysterectomy between Groups A and B. In the multivariate analysis for massive hemorrhage, Group A (odds ratio: 2.73, p = .04) and Group B (odds ratio: 12.69, p < .01) were identified as independent predictive factors. In addition, massive hemorrhage was closely related to the lower posterior bladder and parametrial invasion in both Groups A and B.

CONCLUSIONS

Both clinical and histologic criteria for PAS in the FIGO classification were associated with massive hemorrhage. Diagnosing clinical PAS using the FIGO classification, additional hemostatic procedures might be necessary according to the topographic invasion area.

Is it Possible to Predict Massive Bleeding in Nulliparous Women with Placenta Previa?

OBJECTIVE

 We evaluated risk factors to determine if there were specific risk factors that could predict massive bleeding in nulliparous women with placenta previa.

METHODS

 The participants were classified into two groups. Women with a calculated blood loss ≥ 1,000 mL were included in the massive bleeding group. Women without any signs or symptoms related with hypovolemia or with a calculated bleeding volume < 1,000 mL were categorized into the non-massive bleeding group.

RESULTS

 There were 28 patients (40.6%) with massive bleeding and 41 cases (59.4%) with non-massive bleeding. The calculated blood loss and number of cases that required red cell transfusions were statistically different between the groups (< 0.005 and 0.002, respectively). There were no statistically significant differences in terms of maternal or fetal factors, placental location, or delivery characteristics between the two groups.

CONCLUSION

 We could not determine the predictive features for massive hemorrhage based on clinical features, delivery features, or placental location.

Management of massive hemorrhage in pregnant women with placenta previa

Patients with placenta previa are at risk for intra- and postpartum massive blood loss as well as increased risk of placenta accreta, a type of abnormal placental implantation. This condition can lead to serious obstetric complications, including maternal mortality and morbidity. The risk factors for previa include prior cesarean section, multiparity, advanced maternal age, prior placenta previa history, prior uterine surgery, and smoking. The prevalence of previa parturients has increased due to the rising rates of cesarean section and advanced maternal age. For these reasons, we need to identify the risk factors for previa and identify adequate management strategies to respond to blood loss during surgery. This review evaluated the diagnosis of placenta previa and placenta accreta and assessed the risk factors for previa-associated bleeding prior to cesarean section. We then presented intraoperative anesthetic management and other interventions to control bleeding in patients with previa expected to experience massive hemorrhage and require transfusion.

Efficacy of intraoperative wireless ultrasonography for uterine incision among patients with adherence findings in placenta previa

AIM

We evaluated the effectiveness of intraoperative wireless ultrasonography in determining the location of uterine incision during cesarean delivery in patients with placenta previa who have sonographic adherence findings in order to assess intraoperative blood loss and maternal morbidity.

METHODS

A prospective study using wireless sonography, including 15 patients with previa, was conducted among women with singleton pregnancies who delivered by cesarean section between August 1, 2017, and August 30, 2019. Retrospective study for the control group included 32 patients with placenta previa who underwent cesarean section between January 1, 2016, and July 31, 2017, without wireless sonography. Patients with previa who had adherence findings in prenatal sonography were included in both groups. Logistic regression was used to identify the association between massive intraoperative bleeding loss and use of wireless ultrasound sonography.

RESULTS

Intraoperative blood loss was significantly reduced in the study group compared to that in the control group (P = 0.009). The hospital stay was significantly shorter in the study group compared to the control group (5 days vs 6 days, P < 0.001). The use of intraoperative wireless sonography (P = 0.01) had a significant association with massive intraoperative hemorrhage in multivariable analysis.

CONCLUSION

Our study is the first study to apply a wireless ultrasound sonography device in women with placenta previa during cesarean section to examine maternal morbidity. This latest wireless ultrasound sonography device is advantageous for uterine incision guidance in women with placenta previa and improves maternal morbidity by reducing intraoperative hemorrhage.

Assessment of the massive hemorrhage in placenta accreta spectrum with magnetic resonance imaging

The aim of the present study was to evaluate whether MRI features are able to predict massive hemorrhage of patients with placenta accreta spectrum (PAS). A total of 40 patients with suspected PAS after ultrasound examination were subjected to MRI. Of these, 29 patients were confirmed as having PAS. MRI data were analyzed independently by two radiologists in a blinded manner. Inter-observer agreement was determined. The 29 confirmed patients were divided into two groups (moderate and massive hemorrhage) according to the estimated blood loss (EBL) and blood transfusion, and the MRI features were compared between the two groups. The EBL, as well as blood transfusion, between the patients with and without each MRI feature were compared. The inter-observer agreement between the two radiologists for the 11 MRI features had statistical significance (P<0.05). Intra-placental thick dark bands and markedly heterogeneous placenta were the most important MRI features in predicting massive hemorrhage and blood transfusion (P<0.05). The difference in EBL between the patients with and without focal defect of the uteroplacental interface (UPI) was significant (P<0.05). The differences in blood transfusion between the patients with and without myometrial thinning, disruption of the inner layer of the UPI, increased placental vascularity and increased vascularity at the UPI were significant (P<0.05). These results indicate that MRI features may predict massive hemorrhage of patients with PAS, which may be helpful for pre-operative preparation of PAS patients.

Prediction Model for Massive Transfusion in Placenta Previa during Cesarean Section

PURPOSE

Recently, obstetric massive transfusion protocols have shifted toward early intervention. This study aimed to develop a prediction model for transfusion of ≥5 units of packed red blood cells (PRBCs) during cesarean section in women with placenta previa.

MATERIALS AND METHODS

We conducted a cohort study including 287 women with placenta previa who delivered between September 2011 and April 2018. Univariate and multivariate logistic regression analyses were used to test the association between clinical factors, ultrasound factors, and massive transfusion. For the external validation set, we obtained data (n=50) from another hospital.

RESULTS

We formulated a scoring model for predicting transfusion of ≥5 units of PRBCs, including maternal age, degree of previa, grade of lacunae, presence of a hypoechoic layer, and anterior placentation. For example, total score of 223/260 had a probability of 0.7 for massive transfusion. Hosmer-Lemeshow goodness-of-fit test indicated that the model was suitable (p>0.05). The area under the receiver operating characteristics curve (AUC) was 0.922 [95% confidence interval (CI) 0.89-0.95]. In external validation, the discrimination was good, with an AUC value of 0.833 (95% CI 0.70-0.92) for this model. Nomogram calibration plots indicated good agreement between the predicted and observed outcomes, exhibiting close approximation between the predicted and observed probability.

CONCLUSION

We constructed a scoring model for predicting massive transfusion during cesarean section in women with placenta previa. This model may help in determining the need to prepare an appropriate amount of blood products and the optimal timing of blood transfusion.

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.

Risk scoring system with MRI for intraoperative massive hemorrhage in placenta previa and accreta

BACKGROUND

Placenta previa and accreta are serious obstetric conditions that are associated with a high risk of intraoperative massive hemorrhage.

PURPOSE

To develop a scoring system for intraoperative massive hemorrhage combining MRI and clinical characteristics to predict the risk of massive hemorrhage in placenta previa and accreta STUDY TYPE: Retrospective cohort study.

SUBJECTS

In all, 374 patients consisting of 259 patients with placenta previa and accreta after previous cesarean section (CS) for the derivation cohort and 115 patients for the validation cohort.

FIELD STRENGTH/SEQUENCE

1.5T single-shot fast spin-echo sequence. [Correction added on October 23, 2019, after first online publication: The field strength in the preceding sentence was corrected.] ASSESSMENT: Using the derivation cohort, clinical and MRI data were collected and multivariable logistic regressions analysis was conducted to develop a scoring system for prediction of intraoperative massive bleeding (blood loss volume > 2000 mL). Finally, the scoring system was validated on 115 patients.

STATISTICAL TESTS

Student's t-test, Mann-Whitney U-test, X ² statistics, multivariable analysis, and receiver operating characteristic (ROC) analysis.

RESULTS

Ten indicators, including clinically maternal age (1 point), preoperative hemoglobin level (1 point), gravidity number (1 point), number of CS (1 point), and MRI T₂ dark intraplacental bands (4 points), cervical canal length (3 points), placenta thickness on the uterine scar area (4 points), empty vascular shadow of the uterus (1 point), low signal discontinuity in the muscular layer of the posterior wall of the bladder (6 points) and attachment position of the placenta (1 point) were imputed. From the ROC analysis, a total score of 7 points was identified as the optimal cutoff value, allowing good differentiation of intraoperative massive bleeding in the derivation cohort (AUC, 0.863; 95% confidence interval [CI]: 0.811-0.916) and in the validation cohort (AUC, 0.933; 95% CI: 0.885-0.980).

DATA CONCLUSION

The scoring system for intraoperative massive hemorrhage consists of MRI and clinical indicators, and using a cutoff value of 7 points for a high risk of massive bleeding, the developed scoring system could accurately assess the risk of intraoperative massive hemorrhage in patients with placenta previa and accreta. This scoring system can potentially reduce the incidence of intraoperative massive bleeding by identifying patients at high risk.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2020;51:947-958.

Risk factors for severe postpartum haemorrhage during caesarean section for placenta praevia

The objective of this study was to evaluate the value of clinical and ultrasound risk factors in predicting severe postpartum haemorrhage (PPH) (≥1.5 L) in pregnancies undergoing caesarean section for placenta praevia. This cohort consists of all cases of placenta praevia undergoing caesarean delivery over a period of 5 years in a service unit. Patients and their delivery data were retrieved from an obstetric database. Ultrasound features were prospectively recorded before caesarean section. The incidence of caesarean section for placenta praevia was 0.98% (n = 215). Of these, 12.1% (n = 26) had severe PPH. A logistic regression model showed that major praevia, antepartum haemorrhage before delivery and anterior placenta remained significant factors associated with severe PPH. The sensitivity/specificity and positive/negative predictive value of the model are 96.2%, 59.8%, 24.8% and 99.1%, respectively. Our model had high sensitivity and negative predictive value for severe PPH during caesarean section for placenta praevia.Impact statementWhat is already known on this subject? Placenta praevia is known to be one of the leading causes of severe PPH. Many risk factors have been associated with severe bleeding during caesarean section for placenta praevia. However, the importance of individual factors in predicting pregnancy outcome remains controversial.What the results of this study add? Our model includes only three simple parameters, namely the presence of significant antepartum haemorrhage (APH) from the history, and anterior or posterior placenta and major or minor praevia from ultrasound findings, but could predict up to 96.2% of all severe PPH. More importantly, the absence of APH, a posterior minor praevia, was associated with a negative predictive value of 99.1% of severe PPH, implying that such cases could be treated as 'normal' low risk caesarean sections.What the implications are of these findings for clinical practice and/or further research? This simple model would allow differential pre-operative counselling of patients on risks and complications, planning and preparation of operation, allocation of staff as well as in contingency measures to be taken during operation. The establishment of a differential protocol for placenta praevia based on these simple risks factors and a prospective trial of such a protocol is suggested.

Associated factors of blood transfusion for Caesarean sections in pure placenta praevia pregnancies

INTRODUCTION

This study aimed to evaluate associated factors of blood transfusion for Caesarean sections in pure placenta praevia pregnancies.

METHODS

A case-control study was conducted among 405 pregnant women with placenta praevia who underwent Caesarean delivery between August 2004 and December 2013. 135 of the women received blood transfusions. Another 270 women who did not receive any blood transfusion were randomly selected and served as controls. Maternal demographic data, reproductive history, antepartum profiles and obstetric outcomes were compared between the two groups.

RESULTS

Women in the case group were significantly more likely to be multiparous, deliver at a gestational age of less than 37 weeks, have a prior Caesarean delivery, experience preoperative bleeding and anaemia, and have major and anterior placenta praevia (p < 0.05). Multivariate analysis demonstrated that significant, independently associated factors of blood transfusion were: previous Caesarean section (adjusted odds ratio [OR] 2.30, 95% confidence interval [CI] 1.36-3.90), anterior placenta praevia (adjusted OR 2.30, 95% CI 1.15-4.60), major placenta praevia (adjusted OR 2.39, 95% CI 1.34-4.22), preoperative bleeding of more than 250 mL (adjusted OR 6.11, 95% CI 2.35-15.90), preoperative anaemia (adjusted OR 2.31, 95% CI 1.34-4.00) and emergency Caesarean section (adjusted OR 2.14, 95% CI 1.08-4.22).

CONCLUSION

Previous Caesarean section, anterior placentation, major placenta praevia, preoperative bleeding of more than 250 mL, preoperative anaemia and emergency Caesarean section were independent factors that increased the risk of blood transfusion for Caesarean section in pure placenta praevia pregnancies.

Laterally-positioned placenta in placenta previa

Objectives: To clarify perinatal outcomes of patients with placenta previa (PP) with the placenta mainly positioned in the lateral uterine wall (lateral PP), thereby clinically characterizing this condition.Study design: The retrospective cohort study was performed involving patients with lateral PP between January 2006 and December 2016. The placental position was determined and classified by magnetic resonance imaging.Results: This study included 98 patients with PP, which was classified into three types according to the main placental position sites: lateral (n = 30), anterior (n = 32), and posterior (n = 36) PP. Overall, the median blood loss at cesarean section (CS) was 1808 mL and transfusion was performed for 78 patients (80%). Univariate analysis showed that patients with lateral PP bled less at CS than those with non-lateral PP (anterior + posterior PP) [median 1510 (interquartile range 1080-2168) versus 1975 (1570-2860) mL: p=.02]. The other parameters including rates of conception by assisted reproductive technology, prior CS, antepartum bleeding, and placenta accreta spectrum did not show the significances. Among the three groups of PP (lateral versus anterior versus posterior), patients with lateral PP bled less than those with anterior (p=.05) or posterior (p=.13) PP, but this was nonsignificant [lateral 1510 (1080-2168) versus anterior 2145 (1580-3348) versus posterior 1808 (1533-2555) mL]. When dividing into lateral PP to two types: placenta showing anterior dominancy versus posterior dominancy, patients with lateral PP and anterior dominancy bled more those with posterior dominancy [2430 (1410-3400) versus 1170 (1050-1588) mL: p=.002].Conclusion: Patients with lateral PP bled significantly less than those with non-lateral (anterior or posterior) PP. Patients with lateral PP and anterior dominancy bled more than those with posterior dominancy.

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

BACKGROUND

Placenta accreta spectrum (PAS) disorders may be associated with significant mortality and morbidity for both mother and fetus.

PURPOSE/HYPOTHESIS

To identify MRI risk factors for poor peripartum outcome in gravid patients at risk for PAS.

STUDY TYPE

Prospective.

POPULATION

One hundred gravid women (mean age: 34.9 years) at third trimester, with placenta previa.

FIELD STRENGTH/SEQUENCE

T₂ -SSTSE (single-shot turbo spin echo), T₂ -TSE, T₁ -TSEFS (TSE images with fat-suppression) at 1.5T.

ASSESSMENT

Fifteen MRI features considered indicative of PAS were recorded by three radiologists and were tested for any association with the following adverse peripartum maternal and neonatal events: increased operation time, profound blood loss, hysterectomy, bladder repair, ICU admission, prematurity, low birthweight, and 5-minute APGAR score <7.

STATISTICAL TESTS

Kappa (K) coefficients were computed as a measure of agreement between intraoperative information/histology and MRI results as well as for interobserver agreement; chi-square and Fisher's exact tests were used to explore the association of the MRI signs with clinical complications. A score was calculated by adding all recorded MRI signs and its predictive ability was tested using receiver operating characteristic (ROC) analysis, against all complications, separately; odds ratios (ORs) for optimal cutoffs were determined with logistic regression analysis.

RESULTS

There was excellent agreement (K >0.75, P < 0.001) between MRI and intraoperative findings for invasive placenta, bladder and parametrial involvement. Intraplacental T₂ dark bands, myometrial disruption, uterine bulge, and hypervascularity at the utero-placental interface or parametrium, showed significant association (P < 0.005) with poor clinical outcome for both mother and fetus. The MRI score showed significant predictive ability for each adverse maternal event (area under the curve [AUC]: 0.85-0.97, P < 0.001). The presence of ≥3 MRI signs was the cutoff point for a complicated delivery (OR: 19.08, 95% confidence interval [CI]: 6.05-60.13) and ≥6 MRI signs was the cutoff point for massive bleeding (OR: 90.93, 95% CI: 11.3-729.23), hysterectomy (OR: 72.5, 95% CI: 17.9-293.7), or extensive bladder repair (OR: 58.74, 95% CI: 7.35-469.32). The MRI score was not significant for predicting adverse neonatal events including preterm delivery (P = 0.558), low birthweight (P = 0.097), and 5-minute Apgar score (P = 0.078).

DATA CONCLUSION

Preoperative identification of specific MRI features may predict peripartum course in high-risk patients for PAS.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;50:602-618.

Risk factors for abnormally invasive placenta: a systematic review and meta-analysis

Purpose of the article. To explore the strength of association between different maternal and pregnancy characteristics and the occurrence of abnormally invasive placenta (AIP).Materials and methods: Pubmed, Embase, CINAHL databases were searched. The risk factors for AIP explored were: obesity, age >35 years, smoking before or during pregnancy, placenta previa, prior cesarean section (CS), placenta previa and prior CS, prior uterine surgery, abortion and uterine curettage, in vitro fertilization (IVF) pregnancy and interval between a previous CS, and a subsequent pregnancy. Random-effect head-to-head meta-analyses were used to analyze the data.Results: Forty-six were included in the systematic review. Maternal obesity (Odd ratio, OR: 1.4, 95% CI 1.0-1.8), advanced maternal age (OR: 3.1, 95% CI 1.4-7.0) and parity (OR: 2.5, 95% CI 1.7-3.6), but not smoking were associated with a higher risk of AIP. The presence of placenta previa in women with at least a prior CS was associated with a higher risk of AIP compared to controls, with an OR of 12.0, 95% CI 1.6-88.0. Furthermore, the risk of AIP increased with the number of prior CS (OR of 2.6, 95% CI 1.6-4.4 and 5.4, 95% CI 1.7-17.4 for two and three prior CS respectively). Finally, IVF pregnancies were associated with a high risk of AIP, with an OR of 2.8 (95% CI 1.2-6.8).Conclusion: A prior CS and placenta previa are among the strongest risk factors for the occurrence of AIP.

Effect of site of placentation on pregnancy outcomes in patients with placenta previa

INTRODUCTION

We aimed to evaluate the site of placentation on the pregnancy outcomes of patients with placenta previa.

METHODS

This retrospective study included 678 cases of placenta previa. Basic information and pregnancy outcome data were collected. Differences between the different placenta previa positions and pregnancy outcomes were compared using the chi-square and independent t tests. Logistic and multiple regression analyses were used to calculate the odds ratios (ORs) to determine the risk factors for PAS disorders and postpartum hemorrhage and evaluate the effect of placental attachment site on pregnancy outcomes.

RESULTS

There was no significant difference between the PAS disorders rate and the incidence of complete placenta previa depending on the type of placentation; however, placental attachment site influenced the pregnancy outcome. Placental attachment to the anterior wall was associated with shorter gestational age, low birth weight, lower Apgar score, higher prenatal bleeding rate, increased postpartum hemorrhage, longer duration of hospitalization, and higher blood transfusion and hysterectomy rates compared to cases with lateral/posterior wall placenta. Placental attachment at the incision site of a previous cesarean section significantly increased the incidence of complete placenta previa and PAS disorders compared with placental attachment at a site without incision, but did not significantly influence pregnancy outcomes. Placental attachment to the anterior wall was an independent risk factor for postpartum hemorrhage in patients with placenta previa. Placental attachment to a previous incision site was an independent risk factor for PAS disorders.

CONCLUSION

The site of placental attachment in patients with placenta previa has an important influence on the pregnancy outcome. When the placenta is located on the anterior wall, clinicians should pay attention to the adverse pregnancy outcomes and the possibility of massive postpartum hemorrhage. In cases of placental attachment to the uterine incision site, physicians should be highly vigilant regarding the occurrence of PAS disorders.

Association between birth weight and massive haemorrhage in pregnancy with a low-lying placenta: a 9-year single-centre retrospective cohort study in Japan

A low-lying placenta is a well-known cause of a massive intrapartum haemorrhage. We aimed to evaluate whether neonatal birth weight deviation from the nationwide average could predict a massive haemorrhage during a delivery in the women with a low-lying placenta. This study included 40 women. The main outcomes were a massive haemorrhage and a neonatal birth weight deviation. We used a receiver operating characteristic curve analysis to determine the optimal birth weight deviation cut-off for predicting a massive haemorrhage. A multiple logistic regression model was used to identify the variables significantly associated with a massive haemorrhage. The best cut-off for predicting a massive haemorrhage was a birth weight deviation of +0.51 standard deviations (SDs) from the nationwide average. A birth weight deviation of ≥ +0.51 SDs was significantly associated with an increased massive haemorrhage risk. Impact statement What is already known on this subject? A low-lying placenta is a well-known cause of a massive intrapartum haemorrhage. Therefore, when managing pregnancies with a low-lying placenta, the possibility of severe perinatal bleeding should be considered, and it is desirable to determine reliable predictors of a haemorrhage. However, few studies have reported the predictive factors of a massive haemorrhage in patients with a low-lying placenta. What do the results of this study add? We demonstrated that a birth weight deviation from the nationwide average was significantly associated with a massive intrapartum haemorrhage in patients with a low-lying placenta. To our knowledge, this is the first study to clarify the association between a neonatal birth weight and a massive intrapartum haemorrhage incidence and to determine the optimal birth weight deviation cut-off for predicting a massive haemorrhage in patients with a low-lying placenta. What are the implications of these findings for clinical practice and/or further research? An accurate risk stratification using the foetal weight as a marker for a predicting massive intrapartum haemorrhage may help in the management of patients with a low-lying placenta. Studies with a larger sample size are required to confirm our findings.

Complete Placenta Previa: Ultrasound Biometry and Surgical Outcomes

Objective  To evaluate the relationship between surgical outcomes and ultrasound measurement of placental extension beyond the cervical os in women with placenta previa. Study Design  This is a retrospective cohort study of singleton pregnancies with placenta previa undergoing third-trimester ultrasound and delivering at our institution from 2002 through 2011. For study purposes, an investigator measured placental extension, defined as the placental distance from the internal os across the placenta continuing out to the lowest placental edge. If morbidly adherent placentation was suspected, women were excluded. Receiver operating characteristic (ROC) curves were developed for pertinent surgical outcomes, and multivariate analysis was performed to determine the placental extension with the best predictive discriminatory zone. Results  In total, 157 women had placenta previa, ultrasound, and delivery data: 86 (55%) had a placental extension of <40 mm, and 71 (45%) had a placental extension of ≥40 mm. Women with placental extension of ≥40 mm had increased surgical time, blood loss > 2,000 mL, blood transfusion, and rate of peripartum hysterectomy. After multivariate analysis, only peripartum hysterectomy and surgical time > 90 minutes remained significant, p ≤ 0.05 and p ≤ 0.01, respectively. Conclusion  In women with placenta previa, the placental extension ultrasound measurement of ≥40 mm is a predictor of adverse surgical outcomes.

Conventional MRI features for predicting the clinical outcome of patients with invasive placenta

PURPOSE

We aimed to evaluate whether morphologic magnetic resonance imaging (MRI) features could help to predict the maternal outcome after uterine artery embolization (UAE)-assisted cesarean section (CS) in patients with invasive placenta previa.

METHODS

We retrospectively reviewed the MRI data of 40 pregnant women who have undergone UAE-assisted cesarean section due to suspected high risk of massive hemorrhage caused by invasive placenta previa. Patients were divided into two groups based on the maternal outcome (good-outcome group: minor hemorrhage and uterus preserved; poor-outcome group: significant hemorrhage or emergency hysterectomy). Morphologic MRI features were compared between the two groups. Multivariate logistic regression analysis was used to identify the most valuable variables, and predictive value of the identified risk factor was determined.

RESULTS

Low signal intensity bands on T2-weighted imaging (P < 0.001), placenta percreta (P = 0.011), and placental cervical protrusion sign (P = 0.002) were more frequently observed in patients with poor outcome. Low signal intensity bands on T2-weighted imaging was the only significant predictor of poor maternal outcome in multivariate analysis (P = 0.020; odds ratio, 14.79), with 81.3% sensitivity and 84.3% specificity.

CONCLUSION

Low signal intensity bands on T2-weighted imaging might be a predictor of poor maternal outcome after UAE-assisted cesarean section in patients with invasive placenta previa.

Scoring model to predict massive post-partum bleeding in pregnancies with placenta previa: A retrospective cohort study

AIM

We aimed to identify factors associated with massive post-partum bleeding in pregnancies with placenta previa and to establish a scoring model to predict post-partum severe bleeding.

METHODS

A retrospective cohort study was performed in 506 healthy singleton pregnancies with placenta previa from 2006 to 2016. Cases with intraoperative blood loss (≥2000 mL), packed red blood cells transfusion (≥4), uterine artery embolization, or hysterectomy were defined as massive bleeding. After performing multivariable analysis, using the adjusted odds ratios (aOR), we formulated a scoring model.

RESULTS

Seventy-three women experienced massive post-partum bleeding (14.4%). After multivariable analysis, seven variables were associated with massive bleeding: maternal old age (≥35 years; aOR 1.79, 95% confidence interval [CI] 1.00-3.20, P = 0.049), antepartum bleeding (aOR 4.76, 95%CI 2.01-11.02, P < 0.001), non-cephalic presentation (aOR 3.41, 95%CI 1.40-8.30, P = 0.007), complete placenta previa (aOR 1.93, 95%CI 1.05-3.54, P = 0.034), anterior placenta (aOR 2.74, 95%CI 1.54-4.89, P = 0.001), multiple lacunae (≥4; aOR 2.77, 95%CI 1.54-4.99, P = 0.001), and uteroplacental hypervascularity (aOR 4.51, 95%CI 2.30-8.83, P < 0.001). We formulated a scoring model including maternal old age (<35: 0, ≥35: 1), antepartum bleeding (no: 0, yes: 2), fetal non-cephalic presentation (no: 0, yes: 2), placenta previa type (incomplete: 0, complete: 1), placenta location (posterior: 0, anterior: 1), uteroplacental hypervascularity (no: 0, yes: 2), and multiple lacunae (no: 0, yes: 1) to predict post-partum massive bleeding. According to our scoring model, a score of 5/10 had a sensitivity of 81% and a specificity of 77% for predicting massive post-partum bleeding. The area under the receiver-operator curve was 0.856 (P < 0.001). The negative predictive value was 95.9%.

CONCLUSION

Our scoring model might provide useful information for prediction of massive post-partum bleeding in pregnancies with placenta previa.

Risk factors for massive postpartum bleeding in pregnancies in which incomplete placenta previa are located on the posterior uterine wall

Objective

To identify factors associated with massive postpartum bleeding in pregnancies complicated by incomplete placenta previa located on the posterior uterine wall.

Methods

A retrospective case-control study was performed. We identified 210 healthy singleton pregnancies with incomplete placenta previa located on the posterior uterine wall, who underwent elective or emergency cesarean section after 24 weeks of gestation between January 2006 and April 2016. The cases with intraoperative blood loss (≥2,000 mL) or transfusion of packed red blood cells (≥4) or uterine artery embolization or hysterectomy were defined as massive bleeding.

Results

Twenty-three women experienced postpartum profuse bleeding (11.0%). After multivariable analysis, 4 variables were associated with massive postpartum hemorrhage (PPH): experience of 2 or more prior uterine curettage (adjusted odds ratio [aOR], 4.47; 95% confidence interval [CI], 1.29 to 15.48; P=0.018), short cervical length before delivery (<2.0 cm) (aOR, 7.13; 95% CI, 1.01 to 50.25; P=0.049), fetal non-cephalic presentation (aOR, 12.48; 95% CI, 1.29 to 121.24; P=0.030), and uteroplacental hypervascularity (aOR, 6.23; 95% CI, 2.30 to 8.83; P=0.001).

Conclusion

This is the first study of cases with incomplete placenta previa located on the posterior uterine wall, which were complicated by massive PPH. Our findings might be helpful to guide obstetric management and provide useful information for prediction of massive PPH in pregnancies with incomplete placenta previa located on the posterior uterine wall.

Relation between Birth Weight and Intraoperative Hemorrhage during Cesarean Section in Pregnancy with Placenta Previa

Background

Placenta previa, one of the most severe obstetric complications, carries an increased risk of intraoperative massive hemorrhage. Several risk factors for intraoperative hemorrhage have been identified to date. However, the correlation between birth weight and intraoperative hemorrhage has not been investigated. Here we estimate the correlation between birth weight and the occurrence of intraoperative massive hemorrhage in placenta previa.

Materials and Methods

We included all 256 singleton pregnancies delivered via cesarean section at our hospital because of placenta previa between 2003 and 2015. We calculated not only measured birth weights but also standard deviation values according to the Japanese standard growth curve to adjust for differences in gestational age. We assessed the correlation between birth weight and the occurrence of intraoperative massive hemorrhage (>1500 mL blood loss). Receiver operating characteristic curves were constructed to determine the cutoff value of intraoperative massive hemorrhage.

Results

Of 256 pregnant women with placenta previa, 96 (38%) developed intraoperative massive hemorrhage. Receiver-operating characteristic curves revealed that the area under the curve of the combination variables between the standard deviation of birth weight and intraoperative massive hemorrhage was 0.71. The cutoff value with a sensitivity of 81.3% and specificity of 55.6% was −0.33 standard deviation. The multivariate analysis revealed that a standard deviation of >−0.33 (odds ratio, 5.88; 95% confidence interval, 3.04–12.00), need for hemostatic procedures (odds ratio, 3.31; 95% confidence interval, 1.79–6.25), and placental adhesion (odds ratio, 12.68; 95% confidence interval, 2.85–92.13) were independent risk of intraoperative massive hemorrhage.

Conclusion

In patients with placenta previa, a birth weight >−0.33 standard deviation was a significant risk indicator of massive hemorrhage during cesarean section. Based on this result, further studies are required to investigate whether fetal weight estimated by ultrasonography can predict hemorrhage during cesarean section in patients with placental previa.

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.

Successful treatment of placenta previa totalis using the combination of a two-stage cesarean operation and uterine arteries embolization in a hybrid operating room

A 37-year-old primigravida female with placenta previa totalis was transferred to our hospital at 29 weeks of gestation. A transvaginal ultrasound examination showed a dropped placenta into the uterine cervix and an effaced lower uterine segment. The boundary between the cervical muscle layer and the placenta was unclear. Consequently, although it was unclear whether complication of the adherence of placenta was present or not, massive hemorrhage with atonic bleeding in the lower uterine segment after placenta removal was strongly suspected. As the patient had uncontrolled vaginal bleeding, an emergency cesarean section was performed in a hybrid operating room. A transverse fundal incision of the uterus was made, and a 1143 g healthy neonate was delivered. As no signs of placental detachment or persistent bleeding were found, the uterus was closed, leaving the placenta. Thereafter bilateral uterine arterial embolization (UAE) with absorbable gelatin sponges was performed. On the third day after the operation, a second operation for placental removal. The placenta detached smoothly, but compression sutures were placed to control the bleeding at the site of placental removal around the uterine isthmus. In this case, we were able to conduct the treatment smoothly because of the antenatal ultrasound assessment and precise preparation of the cesarean section with UAE in the hybrid operation room. Using the hybrid operation room, sharing detailed surgical planning in cooperation with the physicians from other departments is important for obtaining a good outcome.

Effect of Placenta Previa on Preeclampsia

Background

The correlation between gestational hypertension-preeclampsia (GH-PE) and placenta previa (PP) is controversial. Specifically, it is unknown whether placenta previa has any effect on the various types of preeclampsia (PE), and the role PP with concurrent placenta accreta (PA) play in the occurrence of GH-PE are not well understood.

Objective

The aim of this study was to identify the effects of PP on GH, mild and severe preeclampsia (MPE and SPE), and early- and late-onset preeclampsia (EPE and LPE). Another aim of the study was to determine if concurrent PA impacts the relationship between PP and GH-PE.

Methods

A retrospective single-center study of 1,058 patients having singleton pregnancies with PP was performed, and 2,116 pregnant women were randomly included as controls. These cases were collected from a tertiary hospital and met the inclusion criteria for the study. Clinical information, including PP and the gestational age at the onset of GH-PE were collected. Binary and multiple logistic regression analyses were conducted after the confounding variables were controlled to assess the effects of PP on different types of GH-PE.

Results

There were 155 patients with GH-PE in the two groups. The incidences of GH-PE in the PP group and the control group were 2.5% (26/1058) and 6.1% (129/2116), respectively (P = 0.000). Binary and multiple regression analyses were conducted after controlling for confounding variables. Compared to the control group, in the PP group, the risk of GH-PE was reduced significantly by 78% (AOR: 0.216; 95% CI: 0.135–0.345); the risks of GH and PE were reduced by 55% (AOR: 0.451; 95% CI: 0.233–0.873) and 86% (AOR: 0.141; 95% CI: 0.073–0.271), respectively; the risks of MPE and SPE were reduced by 73% (AOR: 0.269; 95% CI: 0.087–0828) and 88% (AOR: 0.123; 95% CI: 0.055–0.279), respectively; and the risks of EPE and LPE were reduced by 95% (AOR: 0.047; 95% CI: 0.012–0.190) and 67% (AOR: 0.330; 95% CI: 0.153–0.715), respectively. The incidence of concurrent PA in women with PP was 5.86%; PP with PA did not significantly further reduce the incidence of GH-PE compared with PP without PA (1.64% vs. 2.51%, P>0.05). Binary logistic regression analyses were conducted after controlling for confounding variables, compared with the non-PP + GH-PE group, and the AOR of FGR in the non-PP + non-GH-PE group was 0.206 (0.124–0.342). Compared with the PP + GH-PE group, the AOR of FGR in the PP + non-GH-PE group was 0.430 (0.123–1.500).

Conclusion

PP is not only associated with a significant reduction in the incidence of GH-PE, but also is associated with a reduction in incidence of various types of PE. Concurrent PA and PP do not show association with a reduction in incidence of GH-PE.

Factors associated with placenta praevia in primigravidas and its pregnancy outcome

Aim. To examine the factors associated with placenta praevia in primigravidas and also compare the pregnancy outcomes between primigravidas and nonprimigravidas. Method. A retrospective cohort study was conducted in women who underwent caesarean section for major placenta praevia in a tertiary university hospital from January 2007 till December 2013. Medical records were reviewed. Result. Among 243 with major placenta praevia, 56 (23.0%) were primigravidas and 187 (77.0%) were nonprimigravidas. Factors associated with placenta praevia in the primigravidas were history of assisted conception (P = 0.02) and history of endometriosis (P = 0.01). For maternal outcomes, the nonprimigravidas required earlier delivery than primigravidas (35.76 ± 2.54 weeks versus 36.52 ± 1.95 weeks, P = 0.03) and had greater blood loss (P = 0.04). A vast majority of the primigravidas had either posterior type II or type III placenta praevia. As for neonatal outcomes, the Apgar score at 1 minute was significantly lower for the nonprimigravidas (7.89 ± 1.72 versus 8.39 ± 1.288.39 ± 1.28, P = 0.02). Conclusion. This study highlighted that endometriosis and assisted conception were highly associated with placenta praevia in primigravida. Understanding the pregnancy outcomes of women with placenta praevia can assist clinicians in identifying patients who are at higher risk of mortality and morbidity. Identifying potential risk factors in primigravida may assist in counseling and management of such patients.

Anterior placentation as a risk factor for massive hemorrhage during cesarean section in patients with placenta previa

AIM

In placenta previa (PP), anterior placentation, compared with posterior placentation, is reported to more frequently cause massive hemorrhage during cesarean section (CS). Whether this is due to the high incidence of placenta accreta, previous CS, or a transplacental approach in anterior placenta is unclear. We attempted to clarify this issue.

MATERIAL AND METHODS

We retrospectively analyzed the relation between the bleeding amount during CS for PP and various factors that may cause massive hemorrhage (>2400 mL) (n = 205) in a tertiary center. If the preoperatively ultrasound-measured distance from the internal cervical ostium to the placental edge was longer in the uterine anterior wall than in the posterior wall, we defined it as anterior previa, and vice versa.

RESULTS

Patients with accreta, previous CS, total previa, and anterior placentation bled significantly more than their counterparts. Multivariate logistic regression analysis showed that accreta (odds ratio [OR] 12.6), previous CS (OR 4.7), total previa (OR 4.1), and anterior placentation (OR 3.5) were independent risk factors of massive hemorrhage.

CONCLUSIONS

Anterior placentation, namely, the placenta with a longer os-placental edge distance in the anterior wall than in the posterior wall, was a risk of massive hemorrhage during CS for PP.

Does previa location matter? Surgical morbidity associated with location of a placenta previa

OBJECTIVE

To evaluate the effect of placenta previa location (anterior vs posterior) on cesarean morbidity.

STUDY DESIGN

Retrospective cohort of women undergoing cesarean for placenta previa. The rate of hysterectomy and blood transfusion in the setting of anterior previa was compared with posterior previa. Planned stratified analysis based on delivery history was performed. Logistic regression was performed to control for potential confounders.

RESULT

Two hundred and eighty-five women undergoing cesarean delivery for placenta previa were identified. Women undergoing primary cesareans with an anterior previa had higher rates of blood transfusion (adjusted odds ratio (aOR) 3.13 95% confidence interval (CI) (1.18 to 8.36) and hysterectomy (7.4% vs 0, P=0.001) compared with those with a posterior previa; similarly, women undergoing repeat cesarean with anterior previa had higher rates of hysterectomy (aOR 4.60 95% CI (1.02 to 20.7). The majority of hysterectomies (93.8%) were due to abnormal placentation.

CONCLUSION

An anterior placenta previa increases the risk of hysterectomy for both primary and repeat cesareans due to abnormal placentation. In the absence of accreta, blood transfusion remained a significant cause of maternal morbidity in both anterior and posterior placenta previas. This information may be useful for operative planning.

Analysis of the predictable variables for placenta accreta without placenta previa

OBJECTIVES

To clarify the predictive variables for adherence of the placenta (AP) in cases without placenta previa.

METHODS

A prospective cohort study was conducted between 2008 and 2010. Patients without placenta previa who delivered singleton babies after 36 weeks' gestation were enrolled. The maternal and ultrasonographic variables associated with AP were evaluated at the time of admission for delivery.

RESULTS

A total of 2834 consecutive subjects were included. Placenta accreta without placenta previa was observed in six cases (0.2 %). Two cases in which the placenta was located on the previous uterine scar had AP, but AP was found only in 0.1 % of cases in which the placenta was not on the previous scar (p < 0.001). AP was frequently observed in cases with a history of previous uterine surgery compared to cases without a history [(1.9 vs. 0.1 %) p < 0.001]. AP was observed in 33 % of cases in which no retroplacental clear zone was detected, whereas AP was observed in only 0.1 % of cases with a clear zone (p < 0.001).

CONCLUSION

A past history of uterine surgery, ultrasonographic findings of no retroplacental clear zone, and a placenta on the uterine scar were associated with AP in cases without placenta previa.

Can ultrasonography of the placenta previa predict antenatal bleeding?

PURPOSE

To evaluate the abnormal sonographic (US) findings in patients with placenta previa and bleeding.

METHODS

A total of 182 cases of singleton pregnancies with placenta previa were reviewed. The US findings including the type of placenta previa, placental location, presence of placenta lacunae, lack of clear zone, sinus venosus at the margin of the placenta, velamentous cord insertion, sponge-like echo in the cervix and cervical length were evaluated in relation to episodes of bleeding that required in-patient treatment during pregnancy and/or emergency cesarean section.

RESULTS

Episodes of antenatal bleeding occurred in 102/182 (56%) patients with placenta previa. An emergency cesarean section was performed in 66 (64.7%) of these 102 patients. In the 80 patients without episodes of antenatal bleeding, an emergency cesarean section was performed in only 1 (1.3%). Detection of US findings just prior to cesarean section was not associated with the need for emergency cesarean section due to uncontrollable bleeding from the placenta previa. Frequencies of each US finding at 20 weeks of gestation were not different between the patients who underwent emergency cesarean sections and the others. Frequency of marginal sinus was slightly higher in cases with bleeding episode (16% versus 0%, p < 0.05), but the other US findings were not associated with the occurrence of bleeding episodes during pregnancy.

CONCLUSIONS

No US finding could predict bleeding episodes and the eventual need for an emergency cesarean section. The obstetrician should be aware that sudden bleeding during pregnancy may occur in patients with placenta previa, even in the absence of any other US findings.