Placenta Previa
Placenta previa is defined as implantation of the placenta in the lower uterine segment in advance of the fetal presenting part. The placenta either totally or partially lies within the lower uterine segment. Placenta previa complicates approximately 0.3%-0.5% of pregnancies or about 4.8 per 1,000 deliveries. The risk of recurrent placenta previa is as high as 4% to 8%. The risk of placenta previa increases with the number of prior cesarean sections, rising to 10% with four or more. Although some distinctions in outcome may be made among the different degrees of true placenta previa, all are potentially associated with life-threatening hemorrhage during labor. The degree of placenta previa cannot alone predict the clinical course accurately, nor can it serve as the sole guide for management decisions. Thus, the importance of such classifications has diminished.
The purpose of this document is to present evidence-based approach to the management of placental abnormalities and major obstetric hemorrhage. Attention to improving the hospital systems is necessary for the care of women at risk for major obstetric hemorrhage. It is important in the effort to decrease maternal mortality from hemorrhage. Multidisciplinary team implementation systemic changes are also discussed. It is the responsibility of the physician to decide without delay whether the cause is benign or potentially life-threatening to the mother, fetus, or both. The potential harm from either procrastination or unnecessary intervention may be extreme.