• Clinical science

Antepartum hemorrhage

Abstract

Antepartum hemorrhage is a serious complication of pregnancy occurring within the third trimester. It is associated with significant maternal and fetal morbidity and mortality. Common causes of antepartum hemorrhage are bloody show associated with labor, miscarriage, placental previa, and placental abruption. Rare causes include vasa previa and uterine rupture. Symptoms of placental abruption typically include lower abdominal pain, vaginal bleeding, and a rigid uterus. Placenta previa and vasa previa on the other hand typically manifest prior to rupture of membranes or after rupture of membranes respectively, with painless vaginal bleeding and fetal distress. Uterine rupture, which occurs during labor, is discussed in a separate learning card. In cases of severe hemorrhage, patients may present with signs of hypovolemic shock. Fetal symptoms include signs of fetal stress, such as decelerations on heart monitoring and decreased fetal movements. The diagnosis is primarily clinical and is confirmed via transabdominal or transvaginal ultrasound. The treatment approach depends on maternal symptoms and fetal vitality. A conservative approach with continuous monitoring is advised for asymptomatic patients carrying a healthy fetus, while an emergency cesarean section is indicated in patients with acute symptoms and a live, distressed fetus.

Overview

Differential diagnosis of antepartum bleeding

Condition Onset Pain Additional symptoms Risk factors
Placental abruption
  • Sudden
  • Occurs most often in the third trimester
  • Usually mild to moderate abdominal pain
  • Uterine tenderness
  • Continuous, dark, vaginal bleeding
  • Hypertonic contractions (rigid uterus)
  • Uterine tenderness
  • Premature labor
  • Fetal distress
Placenta previa
  • Painless
  • Bright red vaginal bleeding
Vasa previa
  • Painless
Uterine rupture
  • Sudden
  • During labor
  • Severe abdominal pain

Stillbirth

  • Cramping abdominal pain
  • Vaginal bleeding
  • Features of labor (e.g., uterine contractions)
  • Advanced maternal age
  • Obesity
  • Smoking
  • Multiple gestation
  • Concurrent medical disorders
  • Complicated pregnancy
Rupture of the membranes in velamentous cord insertion
  • Vaginal bleeding
  • Features of fetal hypoxia
Bloody show
  • Associated regular uterine contractions and cervical changes
  • A small amount of blood or blood-tinged mucus that is usually passed prior to labor or in early labor.
Cervical trauma
  • Sudden, typically caused by sexual intercourse
  • Mild to moderate pelvic pain depending on extent of damage
  • Bruised and tender cervix without evidence of active bleeding

Placental abruption

Definition

  • The partial or complete separation of the placenta from the uterus prior to delivery. Subsequent hemorrhage occurs from both maternal and fetal vessels.

Epidemiology

  • Incidence: ∼ 0.2–1% of pregnancies
  • Occurs most often in the third trimester
  • The recurrence rate in subsequent pregnancies is 3–15%.

Etiology

Clinical features

Following placental separation of more than 30%, there is a sudden onset of the following symptoms:

  • Continuous, dark, vaginal bleeding (revealed abruptio placentae)
  • In ∼ 20% of cases, the hemorrhage is mainly retroplacental; vaginal bleeding does not occur (concealed abruptio placentae)
  • Abdominal pain or back pain , uterine tenderness
  • Hypertonic contractions (rigid uterus), premature labor
  • Fetal distress (60% of cases)
  • Vaginal exam contraindicated: may worsen bleeding!

In cases of retroplacental hemorrhage, patients may present with signs of hypovolemic shock without evident vaginal bleeding!

Diagnostics

Placental abruption is a clinical diagnosis

  • Ultrasound (transabdominal, transvaginal): only 25% sensitivity!
    • Presentation of the placental position and a possible retroplacental hematoma
    • Monitoring vital signs of the fetus (heartbeat, fetal movement)
    • To rule out placenta previa in unclear cases
  • Fetal heart rate monitoring (see “Clinical features” above)
  • Laboratory tests: CBC, coagulation factors

Rapid diagnosis and immediate treatment are vital for the survival of both mother and child!

Treatment

General approach

  • Hemodynamic control: monitor vital signs, maintain airways, volume resuscitation, type and crossmatch blood
  • Correct coagulopathy if necessary
  • RhD prophylaxis in RhD negative mothers
  • See also peripartum hemorrhage.

Specific approach according to severity

  • Normal fetal findings and a hemodynamically stable mother
    • Observation, bed rest, regular control
    • Up to the 34th week of pregnancy
    • 34th to 36th week
      • Active uterine contractions present: vaginal delivery
      • No contractions + no signs of fetal distress + bleeding has stopped: expectant management and observation
    • All pregnancies are delivered if acute abruption occurs after 36th weeks.
  • In acute symptoms and a live fetus
  • In acute symptoms and intrauterine fetal death
    • Induction of vaginal delivery through pharmacologic uterine contraction inducers and opening of the amniotic sac
    • An emergency cesarean section must be performed if there is a maternal risk; due to severe bleeding or slow progression of the birthing process, even in cases of intrauterine fetal death.

Complications

References:[1][2][3][4][5]

Placenta previa

Definition

  • Presence of the placenta in lower uterine segment; , which might lead to partial or full obstruction of the neck of the uterus with high risk of hemorrhage (rupture of placental vessels) and birth complications

Epidemiology

  • ∼ 0.3–0.5% of all pregnancies

Etiology

  • Risk factors
    • Maternal age > 35 years, multiparity, short intervals between pregnancies
    • Previous curettage or cesarean section
    • Previous placenta previa, previous/recurrent abortion

Classification

Placenta previa is classified based on how much of the cervical orifice is covered by the placenta.

Clinical features

  • Sudden, painless, bright red vaginal bleeding
  • Usually occurs during the 3rd trimester (before rupture of the membranes), stops spontaneously after 1–2 hours, and recurs during birth
  • Often causes preterm delivery (∼ 45% of cases)
  • Soft, nontender uterus
  • Usually no fetal distress

In contrast to placental abruption, bleeding in patients with placenta previa is painless!

Diagnostics

Treatment

  • Approach
  • Expectant mangament
  • Route of delivery
    • Lower segment cesarean section is almost always preferred; ; ideally scheduled at 36–37 weeks gestation
    • Induction of labor and/or vaginal delivery may be performed in the operating room if the mother is hemodynamically stable, fetal cardiac status is reassuring, and the placenta lies > 2 cm away from the internal os on ultrasonography

Vaginal delivery should never be attempted outside the operating room in a patient with placenta previa

References:[6][7][8][9][10][11][12]

Vasa previa

Definition

  • Condition in which the fetal vessels are located in the membranes near the internal os of the cervix, putting them at risk of injury if the membranes rupture

Epidemiology

  • 1/2500 births

Etiology

Clinical features

Diagnostics

  • Transabdominal or transvaginal ultrasound with color Doppler shows fetal vessels overlying the internal os and decreased blood flow within fetal vessels

Treatment

References:[13]