Department of Ultrasound and Fetal Care Unit, Ain Shams University, Cairo, EgyptEgypt
Departments of Obstetrics and Gynecology, Ain Shams University, Cairo, EgyptEgypt
Department of Obstetrics and Gynecology, Ain Shams University, Cairo, Egypt and Ahmadi Kuwait Oil Company (KOC) Hospital, Ahmadi, KuwaitKuwait
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Objective: This study designed to evaluate outcomes and accuracy of 2D gray-scale ultrasound scan in prenatal diagnosis of Morbid Adherent Placenta (MAP). Patients and methods: Fifty pregnant women ≥28 weeks gestation with suspected MAP studied. 2D trans-abdominal gray-scale ultrasound scan done for studied women to confirm; placental location and findings suggestive of MAP. Intra-operative findings at delivery compared with pre-operative sonographer findings to evaluate outcomes and accuracy of 2D gray-scale ultrasound scan in prenatal diagnosis of MAP. Results: 56%(28/50) of studied women had difficult placental separation, considerable intraoperative blood loss. Bilateral internal iliac artery ligation done to control bleeding in 28%(14/50), intrauterine compression balloon with placenta bed sutures done in 6%(3/50) and cesarean hysterectomy done in 22%(11/50) of studied women. Best 2D gray-scale ultrasound parameters for detection of difficult placental separation and considerable intraoperative blood loss in studied cases were; abnormal placental lacunae (73.9% sensitivity) and exophytic mass invading bladder (100% specificity & 100% PPV). Best 2D gray-scale ultrasound parameters for detection of emergency hysterectomy were; disruption of uterine serosa-bladder interface (81.8% sensitivity) and exophytic mass invading bladder (94.9% specificity, 66.7% PPV and 84.1% NPV). Conclusion: Antenatal diagnosis of MAP is crucial for; proper counseling for possible surgical complications, multidisciplinary team care and recruitment. Best 2D gray-scale ultrasound parameters for detection of difficult placental separation in studied cases were; exophytic mass invading bladder, while, best 2D gray-scale ultrasound parameters for detection of emergency hysterectomy were; disruption of uterine serosa-bladder interface and exophytic mass invading bladder.
Keywords: Outcomes; 2D gray-scale ultrasound; Morbid adherent placenta
Demographic data of 50 studied women with suspected MAP were represented in Table 1.
56%(28/50) of studied women had difficult placental separation, considerable blood loss (≥1500 cc) and received blood transfusion. Bilateral internal iliac artery ligation done to control bleeding in 28%(14/50) of studied women, intrauterine compression balloon with placenta bed sutures done in 6% (3/50) of studied women and cesarean hysterectomy done in 22%(11/50) of studied women. Histopathological examination of surgically removed uteri showed; placenta accreta in 10%(5/50) cases, placenta increta in 8%(4/50) cases and placenta percreta in 4%(2/50 cases). 10%(5/50) cases of bladder injury were recorded during this study. (Table 1)
Number of cesarean deliveries (median 3 (1-4 range) versus 1 (1-2 range); respectively) and parity (median 4 (1-6 range) versus 1 (1-2 range): respectively) were high among women, who had difficult placental delivery, women who had considerable intraoperative blood loss and women required emergency hysterectomy to control bleeding. (Table 2)
All 2D gray scale ultrasound parameters (except abnor-
had difficult placental separation and considerable intraoperative blood loss and emergency hysterectomy compared with women who did not have difficult placental separation or considerable blood loss. (Tables 3 and 4)
Variables Total Number of studied women=50 Age (years) 31.22±4.82* Duration from last cesarean section (years) 3.4±2.39* Gestational age at scan (weeks) 30.6±3.17* Gestational age at delivery (weeks) 34.7±1.2* Preoperative hematocrit 30.8±3.3* 48-hours postoperative hematocrit 27.3±4.1* Postoperative hematocrit drop 3.4 ± 2.4* Considerable intraoperative blood loss (≥1500 cc) 28(56%)** ® Intraoperative blood transfusion 28(56%)** Easy placental separation 22(44%)** Difficult placental separation 28(56%)** No need for additional surgical steps 22(44%)** Bilateral Internal Iliac Ligation 14(28%)** Emergency hysterectomy 11(22%)** Intrauterine compression balloon and placental bed sutures 3(6%)** Histopathology results of surgically removed uteri Placenta accrete 5(10%)** Placenta increta 4(8%)** Placenta percreta 2(4%)** Intraoperative bladder injury 5(10%)** *Data represented as Mean±SD. **Data represented as Number and percentage.
Table 1. Preoperative and intraoperative data of studied women with suspected morbid adher- ent placenta. Women who did Women who had diffi- not have difficult cult placental delivery placental delivery and considerable intra- or considerable P value
operative blood loss intraoperative Significance and required emer- blood loss or regency hysterectomy quired emergency hysterectomy Age (years) 30.3±5.2 30.9±4.1 0.13* (NS) Mean±SD Body Mass Index (BMI), (Kg/m ) 2 25.3±3.2 24.7±2.9 0.32* (NS) Mean±SD Parity 4(1-6) 1(1-2) 0.02** (S) Median (Range) Number of previous cesarean section 3(1-4) 1(1-2) 0.04** (S) Median (Range) Gestational age at delivery (weeks) 35.9±1.7 36.2±1.4 0.18* (NS) Mean±SD *Analysis using independent student’s t-test. **Analysis using Mann-Whitney’s U-test. NS: Non-Significant; S: Significant
Table 2. Women who had difficult placental delivery, considerable intraoperative blood loss and required emergency hysterectomy to stop bleeding compared with women who did not have dif- ficult placental delivery or considerable blood loss or required emergency hysterectomy to stop bleeding.
Regression analysis showed that; the risk of difficult placental separation and considerable intraoperative blood loss increased; 3 times (95% CI; 1.7-8.5) with irregular retro-placen-
2D gray-scale parameters Loss of retro-placental sonolucent space Irregular retro-placental sonolucent area Disruption of uterine serosa-bladder interface Exophytic mass invading bladder Abnormal placental lacunae Data represented as number and percentage. Analysis using Chi-square (X2) test. NS: Non-Significant; S: Significant; 2D: Two Dimensional; RR: Relative Risk; CI: Confidence Interval
Table 3. 2D gray-scale parameters in women who had difficult placental separation and considerable intraoperative blood loss compared with women who did not have difficult placental separation or considerable intraoperative blood loss. Variables emergency hysterectomy require hysterectomy 2D gray-scale parameters Loss of retro-placental sonolucent space Irregular retro-placental sonolucent area
Disruption of uterine serosa-bladder interface Exophytic mass invading bladder Abnormal placental lacunae Data represented as number and percentage. Analysis using Chi-square (X2) test. NS: Non-Significant; S: Significant; 2D: Two Dimensional; RR: Relative Risk; CI: Confidence Interval
Table 4. 2D gray-scale parameters in women who required emergency hysterectomy to stop bleeding compared with women who did not require hysterectomy.
of uterine serosa-bladder interface and 13.4 times (95% CI; 0.8- 22.1) with Exophytic mass invading bladder by 2D gray scale ultrasound scan. (Table 3)
Regression analysis also showed that; the risk of emergency hysterectomy to control bleeding in studied cases of MAP increased; 3.2 times (95% CI; 2-5.2) with irregular retro-placental sonolucent areas, 4.5 times (95% CI; 2.2-9.4) with disruption of uterine serosa-bladder interface and 7.1 times (95% CI; 1.4- 33.7) with Exophytic mass invading bladder by 2D gray scale ultrasound scan. (Table 4)
Best 2D gray-scale ultrasound parameters for detection of difficult placental separation and considerable intraoperative blood loss in studied cases were; abnormal placental lacunae (73.9% sensitivity) and exophytic mass invading bladder (100% specificity & 100% PPV). (Table 5)
Best 2D gray-scale ultrasound parameters for detection of emergency hysterectomy were; disruption of uterine serosabladder interface (81.8% sensitivity) and exophytic mass invading bladder (94.9% specificity, 66.7% PPV and 84.1% NPV). (Table 5)
Hemorrhagic and surgical complications associated of MAP depend on depth of placental invasion and involvement of adjacent structures.21 MAP with bladder invasion is a serious, which necessitate proper antenatal diagnosis and appropriate
Women who had difficult Women who did not have placenta separation and difficult placenta separation P value considerable intraoperative or considerable intraoperative Significance RR (95% CI) blood loss (number=28) blood loss (number=22)
26(92.8%) 7(31.8%) 0.03(S), 2.9(1.5-5.4) 25(89.3%) 5(22.7%) 0.01(S), 3.0(1.7-8.5) 18(64.3%) 2(9.1%) 0.006(S), 7.0(1.8-27.2) 8(28.6%) 0(0%) 0.003(S),1.34(0.8-22.1) 21(75%) 14(63.6%) 0.7(NS), 0.39(0.1-0.8)
Women who required Women who did not P value Significance (number=11) (number=39)
11(100%) 13(33.3%) 0.03(S), 3(1.9-4.6) 11(100%) 12(30.8%) 0.02(S), 3.2(1.9-4.6) 9(81.8%) 7(17.9%) 0.01(S), 4.5(2.2-33.7) 4(36.4%) 2(5.1%) 0.02(S), 7.1(1.4-33.7) 8(72.7%) 26(66.7%) 0.8(NS), 1.1(0.7-1.6)
parity are the two known risk factors to MAP and incidence of MAP is increased concomitantly with increased cesarean section 3,23-25 rates.
Antenatal diagnosis of MAP is crucial for; proper counseling for possible surgical complications, multidisciplinary team care and recruitment.3 Despite its cost and unavailability in many centers, MRI should be reserved for cases with inconclu- 13,15,17 sive sonographic findings.
Fifty pregnant women ≥28 weeks` gestation with expected MAP were studied (only 28 had MAP). 2D trans-abdominal gray-scale ultrasound scan done for studied women to confirm; placental location and findings suggestive of MAP. Intra-operative findings and histopathology results of removed uteri compared with pre-operative sonographer findings to detect accuracy of 2D gray-scale ultrasound scans in prenatal diagnosis of MAP. Forty-six of studied women were delivered at 35 weeks by planned cesarean section, while, 4 women were delivered at 33 weeks because of ante-partum hemorrhage. 56%(28/50) of studied women had difficult placental separation, considerable intraoperative blood loss and received intraoperative blood transfusion. In this study; parity, number of previous cesarean sections were significantly high among women, who had difficult placental delivery, women who had considerable intraoperative blood loss and women who required emergency hysterectomy to control bleeding. Wright et al found that; 41.7% of women with a known placenta accreta had a blood loss of ≥ 5000 (ml).26 Accuracy of 2D gray-scale parameters in prediction of difficult placental separation, considerable intraoperative blood loss Loss of retro-placental sonolucent space Irregular retro-placental sonolucent area Disruption of uterine serosa-bladder interface Exophytic mass invading bladder Abnormal placental lacunae Accuracy of 2D Gray-Scale ultrasound parameters in prediction of emergency hysterectomy Loss of retro-placental sonolucent space Irregular retro-placental sonolucent area Disruption of uterine serosa-bladder interface Exophytic mass invading bladder Abnormal placental lacunae Data represented as percentage. PPV: Positive Predictive Value; NPV: Negative Predictive Value. 2D: Two-Dimensional.
Table 5. Accuracy of 2D gray-scale ultrasound parameters in prediction of difficult placental separation, considerable intraoperative blood loss and emergency hysterectomy.
significant relation between parity, number of previous cesarean deliveries, degree of placental invasion and massive blood loss, Tikkanen, et al. found that; the risk factors of placenta accreta include parity, cesarean section and placenta previa.
Also, Guleria, et al. concluded that; risk factors of AIP (abnormal invasive placentation) were placenta previa and previous cesarean delivery, and Thia, et al. concluded that depth of invasion in MAP is increased with multiple previous surgery or excessive curettage or infection causing defective decidua basa- 28,29 lis.
D’Antonio, et al. concluded that; incidence of AIP increased in past decades due to increasing caesarean section rates and ultrasound has 91% sensitivity and 97% specificity for prediction of all forms of AIP.16
Bilateral internal iliac artery ligation needed in 28%(14/50) of studied women, intrauterine compression balloon with placenta bed sutures needed in 6%(3/50) women and cesarean hysterectomy done in 22%(11/50) women. Histopathological examination of surgically removed uteri showed; placenta accreta in 10%(5/50) cases, increta in 8%(4/50) cases and percreta in 4%(2/50) cases. 10%(5/50) cases of bladder injury recorded during this study. Warshak et al, reviewed 99 women with pathologically confirmed placenta accreta.30 Warshak, et al. concluded that; antenatal detection of placenta accreta was associated with significant decrease in maternal hemorrhage, also Tikkanen, et al. concluded that; antenatal diagnosis of placenta accreta may significantly reduce peripartum blood loss and Chantraine et al, concluded that; antenatal diagnosis of AIP reduces morbidity and undiagnosed cases of AIP led to more 27,30,31 emergency hysterectomies.
Eller, et al. concluded that; planned cesarean hysterectomy and pre-operative ureteric stents were associated with
70% 59.3% 64.% 74.2% 72.6% 63% 65.5% 71% 43.5% 88.9% 76.9% 64.9% 26.1% 100% 100% 61.4% 73.9% 37% 50% 62.5%
70% 48.7% 35.5% 70% 70% 53.8% 37.9% 70% 81.8% 82.1% 56.3% 84.1% 63.4% 94.9% 66.7% 84.1% 72.7% 33.3% 23.5% 81.3%
In this study; best 2D gray-scale ultrasound parameters for detection of difficult placental separation and considerable intra-operative blood loss were; abnormal placental lacunae 26,27 (73.9% sensitivity), exophytic mass invading bladder (100% specificity & 100% PPV) and loss of retro-placental sonolucent zone (74.2% NPV). Also, best 2D gray-scale ultrasound parameters for detection of emergency hysterectomy in studied cases were; disruption of hyperechoic uterine serosa-bladder interface (81.8% sensitivity) and exophytic mass invading bladder (94.9% specificity, 66.7% PPV and 84.1% NPV).
Dwyer, et al. studied 32 women to compare accuracy of trans-abdominal ultrasound and MRI for diagnosis of placenta accrete. They found that ultrasound identified placenta accreta with 93% sensitivity and ruled out placenta accreta with 71% specificity, while, MRI correctly identified placenta accreta with 80% sensitivity and ruled out placenta accreta with 65% specificity.
Warshak, et al. found that ultrasound accurately diagnosed MAP with 77% sensitivity and ruled out MAP with 96% specificity, and, concluded that MRI may be helpful in diagnosis of MAP in cases with equivocal or inconclusive ultrasound findings.
See comment in PubMed Commons bel Comstock and colleagues, to detect accuracy of ultrasound in detection of placenta accreta in high-risk patients, conducted large prospective study.33 They, concluded that; multiple vascular spaces inside placenta (placental lacunae) was the most diagnostic sign for placenta accrete with high PPV and obliteration of retro-placental is not reliable sign for diagnosis of placenta accreta. Comstock and colleagues, found that absence of retro-placental space is not diagnostic sign to MAP, since the spaces may be normally absent without MAP and they recommended use of color Doppler to 32 33
Wong, et al. concluded that loss of placental-uterine interface and prescence of abnormal vessels crossing this interface were the most specific criteria to diagnose the MAP using 2D gray-ultrasound scan.
Wong, et al. found that the major risk of placenta accreta is severe hemorrhage when the placenta separated at delivery. They concluded that the extent of myometrial involvement and the vascularity could assessed by the observation of the extent of placental – uterine wall interface disruption and the vessels crossing the interface disruption sites. In addition, they concluded that such assessment results in strategic planning of management of the placenta at delivery with favourable pregnancy outcomes.34
Japaraj, et al. found that the prominent gray scale ultrasound sign to diagnose the placenta accreta was dilated vessels extending from placenta to myometrium, also, Shi et al found that; the most prominent gray scale sign to diagnose the placenta accreta was dilated vessels extending from placenta to myome- 35,36 trium.
Antenatal diagnosis of MAP is crucial for; proper counseling for possible surgical complications, multidisciplinary team care and recruitment. Best 2D gray-scale ultrasound parameters for detection of difficult placental separation in studied cases were; exophytic mass invading bladder, while, best 2D gray-scale ultrasound parameters for detection of emergency hysterectomy were; disruption of uterine serosa-bladder interface and exophytic mass invading bladder.
Authors are grateful to all women agreed to participate in this study.
No conflict of interest exists in relation to this manuscript.
All authors were contributed significantly and are responsible for the content of this manuscript.