Abruptio Placentae

Occurs in 0.4-1% of pregnancies, and the incidence is increasing, particularly among African Americans.

Associated with the following conditions: preeclampsia, hypertension, chorioamnionitis, cocaine use, alcohol use, trauma, increased age and parity, smoking, premature rupture of membranes, prior abruption, and multiple gestation.

Maternal: Antepartum and postpartum hemorrhage, DIC, and death.

Fetal: Hypoxia, prematurity, and fetal demise. Placental separation may lead to reduced gas exchange surface area, and maternal hypotension will worsen uteroplacental blood flow.

Maternal risk lies in severity of abruption, whereas fetal risk depends on both severity and gestational age at time of abruption.

Concealed hemorrhage in a retroplacental hematoma may not manifest as vaginal bleeding and can lead to considerable underestimation of maternal hypovolemia.

Postpartum hemorrhage refractory to usual oxytocic agents; some believe old blood can infiltrate into and between uterine muscle fibers and decrease the effectiveness of uterine contractions (Couvelaire uterus). May need peripartum hysterectomy as a last resort.

Maternal coagulopathy occurs in 10% of cases.

Fetal distress and demise.

Along with placenta previa, a major cause of antepartum hemorrhage, maternal mortality, and perinatal mortality.

Perinatal mortality is 12%, but it varies depending on severity of abruption and gestational age.

Classical clinical triad of metrorrhagia, uterine hypertonia, and abdominopelvic pains presents in only 9.7% of cases.

Placental abruption is the most common condition (37%) associated with DIC in obstetric pts. DIC is probably because of the release of thromboplastin into the central circulation by placental tissues at abruption site.

Postpartum hemorrhage correlates directly with severity of coagulopathy.

Blood and blood clots in muscle fibers may inhibit ability of uterus to contract, which leads to more blood loss.

Separation of placenta from uterine wall along decidual plane between membranes and uterus