**3. The management of placenta accreta in women with placenta previa**

We devised a novel scoring system for predicting placenta accreta in women with placenta previa, and in a prospective cohort study evaluated the diagnostic efficacy of this scoring system named the placenta previa with adherent placenta (PPAP) score [11]. The PPAP score is composed of two categories: (1) past history of CS, surgical abortion, and/or uterine surgery and (2) US and MRI findings. Each category is graded as 0, 1, 2, or 4 points, yielding a total

Women with placenta previa who had PPAP score ≥ 8 were considered to be at a high risk for placenta accreta. The PPAP score yielded 91.3% sensitivity, 98.0% specificity, 87.5% PPV, and 98.7% NPV for predicting placenta accreta in women with placenta previa [11]. However, the

> 1 2 ≥ 2 4

> <3 0 ≥3 2

> Present 2 Placenta is located on the uterine

> 1 2 ≥ 2 4

> Equivocal 2 Present 4

> Equivocal 1 Present 2

> Present 2

Yes 2

4

**Variables Level of variable Score**

Number of previous CS 0 0

Other uterine surgery No 0

USG Grade of placental lacunae 0 0

MRI Suspicious of placenta accreta No 0

**Table 1.** The variables and scores in the PPAP scoring system.

PPAP, placenta previa with adherent placenta; CS, cesarean section; USG, ultrasonography; and MRI, magnetic resonance

scar

Loss of clear zone Absent 0

Turbulent blood flow Absent 0

Irregular sign Absent 0

score between 0 and 24 (**Table 1**).

**Past history**

88 Placenta

abortion

imaging.

Number of previous surgical

**Imaging examination**

All pregnant women with placenta previa suspected to have placenta accreta should be managed at specialized tertiary centers [22]. Their deliveries should be performed by an experienced medical team consisted of obstetric surgeons, urologists, general surgeons, and gynecologic oncologists [23]. Planned cesarean hysterectomy decreases the morbidity and mortality rates in women complicated by placenta accreta [3]. The timing of delivery in such women must be individualized; however, a recent study suggested that delivery at 34 weeks of gestation (GW) in stable women with placenta accreta optimized the outcomes of both mothers and neonates [24].

The anesthesiologists should assess which anesthetic techniques are used before delivery. Both general and regional anesthetic techniques are available, and the decision of which type of technique to be used should be made on an individual basis [23]. Preoperative cystoscopy with placement of ureteral stents may help prevent accidental urinary tract injury. In addition, sufficient amount of blood products should be available in the operating room.

Planned preterm cesarean hysterectomy with the placenta left in situ is generally recommended for women with suspicion of placenta accreta, because forced removal of the placenta causes massive hemorrhage. Midline vertical incision may be considered because it provides sufficient exposure if hysterectomy is needed. CS using transverse uterine fundal incision method is often used to avoid the placenta and allow delivery of the infant.

Hysterectomy is performed in the usual fashion. In some cases with anterior placenta accreta, especially in cases with placenta percreta, partial resection of the bladder wall is necessary. On the other hand, if the women have a strong desire for future fertility, conservative approach, i.e. leaving the placenta in situ, may be considered. However, a review, which summarized the conservative management of 60 women with placenta accreta, showed that infection occurred in 11 of the 60 women (18%), bleeding in 21 (35%), and disseminated intravascular coagulation in 4 (7%) [25]. Therefore, this conservative approach should be considered only when women are willing to accept the risks involved in this approach.

There has been lack of sufficient evidence for beneficial effects of prophylactic catheter placement for balloon occlusion or artery embolization [26–28] as well as treatment with methotrexate [29–31] . Therefore, a firm recommendation on the use of these procedures cannot be made [23, 31]. It is difficult to establish evidence-based management strategies for placenta accreta in pregnancy with placenta previa. Therefore, clinicians should manage these women by suitable approaches in each medical institution.

**Figure 2** shows an algorithm used in the Kobe University Hospital for the management of pregnant women with placenta previa. All pregnant women with placenta previa receive workup for placenta accreta in inpatient or outpatient care. If women have bleeding, they are hospitalized immediately and receive intravenous administration of tocolytic agents such as magnesium sulfate or β-stimulant. Even if they do not have bleeding, they are hospitalized at 32–34GW. Women have a PPAP score ≥ 8, who are suspected of having placenta accreta, receive both preoperative internal iliac artery occlusion balloon catheters placement and elective CS at 35–37GW.

**Figure 3** shows a flow algorithm used in the Kobe University Hospital for the preoperative preparation and operative procedures for women with suspicion of placenta accreta. Women with placenta previa had a PPAP score ≥ 8, who were suspected of having placenta accreta, received preoperative internal iliac artery occlusion balloon catheters placement. After fetal delivery by a CS using transverse uterine fundal incision method, the internal iliac artery occlusion balloon catheters were inflated. After occlusion of the artery, local injection of oxytocin into the myometrium and uterine massage were performed to induce spontaneous placental separation. If placental separation did not occur at all and women did not have a desire for future fertility, cesarean hysterectomy was performed. When the placenta was not partially separated, partial resection of uterine wall or removal of placenta using advanced bipolar was performed.

**Author details**

Kobe, Japan

**References**

Kenji Tanimura and Hideto Yamada\*

placenta accreta. CS, cesarean section.

\*Address all correspondence to: yhideto@med.kobe-u.ac.jp

Obstetrics and Gynecology. 2010;**202**:38 e31-38 e39

Department of Obstetrics and Gynecology, Kobe University Graduate School of Medicine,

**Figure 3.** A flow algorithm for the preoperative preparation and operative procedures against women with suspicion of

Management of Placenta Accreta in Pregnancy with Placenta Previa

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[1] Wu S, Kocherginsky M, Hibbard JU. Abnormal placentation: Twenty-year analysis.

[2] Angstmann T, Gard G, Harrington T, Ward E, Thomson A, Giles W. Surgical management of placenta accreta: A cohort series and suggested approach. American Journal of

American Journal of Obstetrics and Gynecology. 2005;**192**:1458-1461

**Figure 2.** An algorithm for the management of pregnant women with placenta previa. MRI, magnetic resonance imaging; GW, weeks of gestation; NRFS, non-reassuring fetal status; and CS, cesarean section.

Management of Placenta Accreta in Pregnancy with Placenta Previa http://dx.doi.org/10.5772/intechopen.79185 91

**Figure 3.** A flow algorithm for the preoperative preparation and operative procedures against women with suspicion of placenta accreta. CS, cesarean section.
