History and exam

Key diagnostic factors

common

vaginal bleeding

Abruption classically presents with bleeding associated with abdominal pain, as compared with the painless bleeding of placenta previa.[18]

It is important to note that it may not be present in cases of concealed abruption, particularly if the placenta is located posteriorly within the uterus.

abdominal pain

Abdominal pain is a common symptom of abruption. Abruption must be high on the differential diagnosis list whenever abdominal pain occurs in the second half of pregnancy. However, placenta previa may present with painful contractions, and abruption may occur without typical pain.[18][47]

uterine contractions

High-frequency, low-amplitude uterine contractions occur commonly in abruption.[18]

Women with abruption are frequently in labor. This is partly due to the action of thrombin, a powerful uterotonic agent.

uterine tenderness

The uterus is frequently tender to palpation and may feel hard, with the consistency of wood.

Other diagnostic factors

uncommon

lower back pain

May be the presenting symptom of a concealed abruption.

fetal death

Common if more than 50% of the placenta is separated.[48]

Risk factors

strong

chronic hypertension

Associated with an increased risk of abruption.[2][14][15][16]

preeclampsia

Associated with an increased risk for abruption.[2][17][18][19]

smoking

Consistently been demonstrated to be an important risk factor, almost doubling the risk for placental abruption.[14][20][21] The risk of abruption is correlated to the number of cigarettes smoked per day, and the duration of smoking.[22]

cocaine use

Several studies have documented the association of abruption with cocaine use.[23][24][25] It is thought that acute vasospasm is the etiology of this placental separation.

trauma

Associated with an increased risk for abruption, even in the absence of direct uterine trauma.[26][27][28] Shearing forces associated with sudden movement may cause placental separation. This separation may become clinically evident only several hours or days after the trauma. In particular, domestic violence and motor vehicle accidents may be associated with abruption.

chorioamnionitis

Associated with increased risk for abruption.[18][33]

uterine malformations

One study has found that uterine malformations carried an 8-fold increased risk for abruption.[20]

prior placental abruption

Carries an increased risk of abruption in subsequent pregnancies.[20][35][36][37][38]

oligohydramnios

Strongly associated with abruption.[34]

weak

prior cesarean delivery

Population-based studies have found that a prior cesarean carries a risk for placental abruption in a subsequent pregnancy.[20][29][30][31]

preterm premature rupture of the membranes

Risk is increased, particularly in the presence of severe oligohydramnios (largest vertical amniotic fluid pocket <2 cm).[32] Intra-amniotic infection further increases the risk for abruption.

multiparity

The risk of abruption increases in multiparous women.[17]

advanced maternal age

Several studies have found a weak association between increasing maternal age and placental abruption.[33]

polyhydramnios

Predisposes to abruption, particularly if the membranes rupture.[33]​[34]​​ The sudden uterine decompression may cause shearing of the placenta from the uterine wall.

multifetal gestations

Rate of abruption is higher than among singleton pregnancies, with the risk of abruption increasing with the number of fetuses. One study found abruption in 6.2 per 1000 singleton births, 12.2 per 1000 twin births, and 15.6 per 1000 triplet births.[39]

uterine leiomyomas

Women with leiomyomas have more than double the rate of abruption as women without leiomyomas.[40]

thrombophilias

There is a complex relationship between thrombophilias and abruption.[12][41]​ Some studies have found that among women with abruption there is a higher proportion of thrombophilias than among pregnant women without known thrombophilias.[41][42]​ In another study, placental abruptions in pregnant women with thrombophilias were shown to have higher rates of infarctive placental lesions and decidual necrosis than pregnant women with placental abruptions who did not have thrombophilias, again suggesting some relationship between thrombophilia and abruption.[43] However, there is no evidence to suggest that women with thrombophilias have a higher rate of abruption than those without thrombophilias.[44][45]​ The American College of Obstetricians and Gynecologists guideline recommends that thrombophilias are no longer tested for after placental abruption, as they do not appear to increase the risk of abruption.[13]

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