Placenta Accreta and Cesarean Scar Pregnancy: Overlooked Costs of the Rising Cesarean Section Rate

Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, 622 West 168th Street, PH 16-66, Columbia University, New York, NY 10032, USA.
Clinics in Perinatology (Impact Factor: 2.13). 10/2008; 35(3):519-29, x. DOI: 10.1016/j.clp.2008.07.003
Source: PubMed

ABSTRACT An unintended consequence of the rising cesarean section rate is abnormal placentation in subsequent pregnancies, leading to the clinical complications of placenta accreta and cesarean scar pregnancies. Both of these clinical entities are associated with high rates of maternal morbidity and mortality. This article reviews the potential mechanisms by which uterine scarring may lead to abnormal trophoblast invasion, the association of cesarean section with placenta accreta and scar pregnancies, current management, and suggestions for future research to reduce the incidence of these potentially devastating complications of pregnancy.

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    ABSTRACT: It is well known that caesarean section rates have been increasing in Australia for a number of years. Specifically, in the ten years from 1998 to 2007 the caesarean section rate increased by 46% from 21.1% in 1998 to 30.9% in 2007 1 . In 2007, Queensland had the highest caesarean rate of any Australian state and territory at 33.1%. Increasing rates of caesarean section have contributed to a global increase in interest and awareness of adverse maternal and neonatal outcomes associated with caesarean delivery. This report documents the incidence of four of these adverse maternal outcomes (placenta praevia, placenta accreta, placental abruption and uterine rupture) in Queensland. Placenta praevia is a condition where the placenta is implanted in the uterus in such a position that it obscures (partially or totally) the internal cervical os * . Placenta accreta occurs when the placenta adheres to the muscle of the uterus rather than the uterine lining. Previous uterine surgery (including caesarean section) and increasing maternal age are the main risk factors for placenta accreta. Women with current placenta praevia and a past caesarean section are at very high risk of placenta accreta, particularly as the number of past caesareans increases 2 . Placenta accreta (and to a lesser extent, placenta praevia) commonly results in bleeding during the pregnancy and/or at birth, often requiring blood transfusion, and in life-threatening cases, emergency caesarean hysterectomy 2-4 . Placental abruption occurs when the placenta separates prematurely from the uterus prior to delivery, while uterine rupture refers to the tearing of the uterine wall during pregnancy or delivery. Uterine rupture may occur when vaginal births are attempted after a past caesarean section 5 .

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