Pathological attachment of the placenta: diagnosis, management and delivery

Abstract

The incidence of placenta previa is 0.2–0.9% but continues to be one of the most serious factors in the development of obstetric’s bleeding and perinatal losses. The situation is aggravated by the fact that placenta previa is combined with various variations of abnormal (deep) attachment of the placenta to the uterus (placenta adhaerens, accreta, increta, percreta). Placenta previa, placenta accreta, and vasa previa cause significant maternal and perinatal morbidity and mortality. With the increasing incidence of both cesarean delivery and pregnancies using assisted reproductive technology, these 3 conditions are becoming more common. Placental accretion remains the main cause of maternal hemorrhage and obstetric hysterectomy, resulting in significantly high maternal morbidity and mortality. Risk factors for placenta previa include prior cesarean delivery, pregnancy termination, intrauterine surgery, smoking, multifetal gestation, increasing parity, and maternal age. Advances in ultrasound have facilitated prenatal diagnosis of abnormal placentation allowing the development of multidisciplinary management plans to achieve the best outcomes for mother and baby. Purpose — to review the literature on abnormal placentation, including an evidence-based approach to diagnosis, management and treatment; to follow the evolution of this obstetric pathology in recent years and the complications that may arise. Identification of risk factors, correct antenatal and preoperative diagnosis, multidisciplinary treatment and counseling will help in the overall management of women with placenta accreta and reduce maternal morbidity. According to the literature, it can be concluded that true placenta previa or placenta percreta, as well as suspected placenta previa (for example, in cases with a history of caesarean section in anamnesis), should be managed and delivered by caesarean section in a tertiary health facility. In no case should the placenta be separated if edematous blood vessels with visible placental blood flow after laparotomy are found in the area of attachment of the placenta to the anterior wall of the uterus, as well as when the diagnosis is placenta percreta or placenta increta. As a tactic, not only primary hysterectomy should be considered, but also conservative therapy or delayed hysterectomy (two-stage hysterectomy). In a situation where placenta accreta or partial placenta accreta cannot be accurately diagnosed, a good understanding of hemostasis with balloon catheter occlusion, various methods of suture hemostasis, and total hysterectomy procedures should be considered.