Placental abruption

By trimester

Weeks 1–13

1st trimester

Placental abruption is primarily a condition of the second half of pregnancy. Bleeding or significant pain earlier in pregnancy still needs assessment because several other urgent conditions can look similar. Do not use the usual timing of abruption to dismiss severe symptoms in the first trimester.

Weeks 14–27

2nd trimester

Abruption is described mainly in the second half of pregnancy. Vaginal bleeding, persistent abdominal or back pain, a tender or tight uterus, repeated contractions, reduced movement after movement has become established, or symptoms after a fall or abdominal blow need urgent assessment, including earlier in the second trimester.

Weeks 28–birth

3rd trimester

Most abruptions occur in the third trimester. Heavy or concealed bleeding can cause maternal instability, and placental separation can reduce fetal oxygen. Go directly to labor and delivery or emergency care for bleeding, sudden persistent pain, a rigid or tender uterus, frequent contractions, reduced fetal movement, dizziness, or faintness.

What does the evidence show for placental abruption?

• ACOG identifies vaginal bleeding with abdominal or back pain as the most common placental abruption pattern. Placental separation can reduce fetal oxygen and cause substantial maternal blood loss, so bleeding in later pregnancy warrants prompt obstetric contact rather than home observation. 1
• MedlinePlus explains that blood may remain trapped behind the placenta, so an abruption can cause cramping, uterine tenderness, contractions, or altered fetal movement without visible bleeding. It also lists a fall, motor vehicle crash, or blow to the abdomen among relevant trauma exposures. 2
• Placental abruption is a clinical emergency assessed with maternal vital signs, bleeding and uterine findings, fetal heart monitoring when gestational age permits, and selected laboratory and imaging studies. No single laboratory test or imaging study definitively confirms or excludes every case. 3
• In a retrospective study of 149 consecutive patients scanned for suspected abruption at or after 24 weeks, the 55 who delivered within 14 days yielded ultrasound sensitivity of 24% and specificity of 96%. A positive scan was informative, but a negative scan could not rule out abruption. 4
• A 2023 review focused on abruption from 34 weeks through term describes vaginal bleeding, abdominal pain, and abnormal fetal heart patterns as variable presentations. Severe bleeding, maternal instability, coagulopathy, or fetal compromise can require urgent birth, with decisions based on the whole clinical picture rather than blood seen at home. 5

When should I call my provider about placental abruption?

Go to labor and delivery or emergency care now for vaginal bleeding with sudden or persistent abdominal or back pain, a tender or rigid uterus, frequent contractions, reduced fetal movement, weakness, dizziness, fainting, pale or clammy skin, or symptoms after significant abdominal trauma. Call emergency services for heavy bleeding, collapse, severe weakness, or inability to travel safely. Absence of visible blood does not make these symptoms safe to watch at home. Trust your read on your own body. If something feels off beyond the list above, please consult your healthcare provider rather than waiting it out.