What are the presenting signs and symptoms of abruptio placenta and how is the diagnosis made?
Classically, abruptio placenta is described as painful bleeding. The patient may experience a sudden “tearing” pain in the abdomen, followed by the onset of vaginal bleeding and labor pains. A tumultuous labor pattern follows, with frequent contractions and an increase in base tone of the uterus. The patient may state that it feels as though the contraction never ends. The amount of vaginal bleeding is variable and does not always correlate with the degree of placental separation. If the abruption is central, then little vaginal bleeding may be noted, as most of the bleeding will be retroplacental; however, an increase in uterine fundal height may occur as up to 2 liters of blood may collect behind the placenta. Blood extravasation into the myometrium causes the purple-colored Couvelaire uterus. Severe hemorrhage may lead to maternal hypovolemic shock, fetal distress, or fetal demise. Disseminated intravas-cular coagulopathy (DIC) may also occur in the face of a severe abruption. Pritchard and Brekke (1967) were the first to demonstrate that the retroplacental clot could not account for the degree of systemic hypofibrinogenemia seen in abruptio placenta. Gilabert and colleagues (1985) explained how open venous sinuses beneath the abrupted placenta could allow thromboplastic material to enter the maternal circulation and initiate DIC.
Diagnosis of abruption is initially made by clinical eval-uation. Ultrasound evaluation of the placenta may identify a retroplacental clot and separation of the placenta from the uterine wall. After delivery, examination of the placenta may demonstrate an adherent clot; however, the placenta may appear normal.