Abnormally invasive placentation: diagnosis and management

Abstract

Abnormal placental invasion is associated with increased maternal morbidity and mortality. In an abnormally invasive placenta (AIP), the placental villi are not confined by the innate barrier of the uterine endometrium and invade the uterine myometrium and potentially even the uterine serosa. During the antenatal period, signs of abnormal invasion can be seen on ultrasound from as early as the first trimester. Typically, placental lacunae, a thin myometrium, abnormal blood flow in the placenta and myometrium, and/or an interrupted bladder edge should raise the clinical suspicion of AIP. Women with suspected AIP should be referred to centres with appropriate experience in the management of these cases, to optimize outcomes. Women are at significant risk of haemorrhage and other surgical complications. Therefore, skilled surgeons, anaesthetists and interventional radiologists should be involved in the planning and conduct of delivery of the baby. Some cases are not detected antenatally, only being recognized at the time of delivery. Appropriate assistance should be sought to plan and complete the delivery in these cases.