Placenta Previa vs Placental Abruption

Maternal & Newborn · High-Risk Pregnancy (Preeclampsia, GDM)·Updated 2026-10-28

What it is

In placenta previa, the placenta implants in the lower uterine segment over or near the internal cervical os; as the lower segment thins and the cervix begins to dilate, placental vessels tear and cause painless bright red bleeding. In placental abruption, a normally implanted placenta separates early; bleeding behind the placenta causes pain, a tender, rigid uterus and loss of fetal oxygenation. In abruption the bleeding can be concealed, so visible blood underestimates the loss.

What the NCLEX focuses on

Previa: sudden, painless, bright red bleeding in the second or third trimester, a soft nontender uterus, and often a high presenting part or malpresentation.
Abruption: dark red or no visible bleeding, sudden constant abdominal or back pain, a rigid board-like uterus, and fetal distress.
Previa risk factors: previous cesarean or uterine surgery, multiparity, multiple gestation, advanced maternal age and smoking; previa with a prior cesarean raises the risk of placenta accreta.
Abruption risk factors: hypertension and preeclampsia, cocaine use, smoking, abdominal trauma and a previous abruption.
Previa is diagnosed by ultrasound; no digital vaginal examination is performed.
Abruption can trigger disseminated intravascular coagulation (DIC): bleeding from IV sites and gums, falling platelets and fibrinogen, and prolonged clotting times.
Betamethasone is given between 24 and 34 weeks when birth is likely within 7 days; an Rh-negative client receives Rh immune globulin after bleeding.

Priority nursing actions

Assess maternal vital signs, bleeding amount and color, pain and uterine tone, and apply the external fetal monitor.
Position the client on her side.
Start two large-bore IV lines and send CBC, type and crossmatch, coagulation studies and fibrinogen.
Give IV fluids and blood products as prescribed and keep urine output at 30 mL/hour or more.
Keep the client NPO and prepare for cesarean birth with heavy bleeding or fetal compromise.

Numbers to know

Finding	Placenta previa	Placental abruption
Pain	Painless	Sudden, constant, severe abdominal or back pain
Bleeding	Bright red, visible, often recurrent	Dark red or concealed; shock out of proportion to visible blood
Uterus	Soft, relaxed, nontender	Rigid, board-like, tender
Fetal heart rate	Usually reassuring at first	Late decelerations, minimal variability, bradycardia
Main risk factor	Previous cesarean birth	Hypertension or cocaine use
Major complication	Hemorrhage, placenta accreta	DIC, hemorrhagic shock, fetal death
Labs to follow	Hemoglobin, type and crossmatch, Rh status	Platelets, fibrinogen, PT and aPTT, D-dimer

Common exam traps

Choosing a sterile vaginal examination to check dilation in previa: wrong because it can tear the placenta and cause hemorrhage.
Choosing fundal massage for a client with abruption: wrong because massage does not stop bleeding from a separating placenta.
Choosing terbutaline to stop contractions in abruption: wrong because tocolysis is contraindicated with active bleeding and it masks shock with tachycardia.
Choosing to judge an abruption by the visible blood: wrong because bleeding can be concealed behind the placenta.
Choosing to call painless bright red bleeding normal spotting: wrong because any third-trimester bleeding needs immediate evaluation.

What to teach

With previa, keep pelvic rest: nothing in the vagina, including intercourse, tampons and douching, and avoid strenuous activity.
Come in immediately for any bleeding, abdominal pain or contractions, and count fetal movements daily.
To lower abruption risk, stop smoking and cocaine use and control blood pressure.
Wear the lap belt low across the hips and report any abdominal trauma, even when minor.

Client handout: Pregnancy Warning Signs (nurse guide and printable patient handout).

Try 2 NCLEX-style questions on this topic

From the NCLEXPace question bank. Pick your answers, then check them inside NCLEXPace.

Question 1 · QID FDD7EFA4

The nurse assesses clients in the third trimester who present with vaginal bleeding. For each finding, indicate whether it is more consistent with placenta previa or with placental abruption.

	Placenta previa	Placental abruption
Dark red bleeding with constant abdominal pain
Rigid, board-like uterus that is tender to palpation
Painless bright red bleeding that began without warning
Soft, non-tender uterus with the fetal head still high in the pelvis
History of cocaine use and chronic hypertension

Question 2 · QID EDDEDEDC

A client at 31 weeks of gestation with a known complete placenta previa is admitted with a second episode of bright red vaginal bleeding. Which prescription should the nurse question?

Select the best answer.

A. Betamethasone 12 mg intramuscularly now and a second 12 mg dose 24 hours later if the client remains undelivered
B. Continuous electronic fetal heart rate and contraction monitoring while the episode of vaginal bleeding is being evaluated
C. Type and crossmatch for 2 units of packed red blood cells so compatible blood is available if the bleeding increases
D. Sterile vaginal examination to assess cervical dilation

See the answers and full rationales

The correct answers, the reasoning for every option and 3,200+ more NCLEX questions are inside NCLEXPace. Create your account, then choose a plan to open them.

Create Account →

More tips on Maternal & Newborn

Prenatal Care: Labs, Fundal Height and Danger SignsDate the pregnancy, time the routine prenatal labs, interpret fundal height, and teach the danger signs a pregnant client reports at once.Fetal Heart Rate Patterns and DecelerationsRead baseline, variability and decelerations, match each deceleration to its cause, and give intrauterine resuscitation in the right order.Postpartum Hemorrhage: Recognize Early, Act FastSpot hemorrhage before the blood pressure falls, firm a boggy uterus, empty the bladder, and give uterotonics within their contraindications.

Sources

Perry SE, Hockenberry MJ, Cashion K, Alden KR, Olshansky E, Lowdermilk DL. Maternal Child Nursing Care. 7th ed. Elsevier; 2022.
American College of Obstetricians and Gynecologists; Society for Maternal-Fetal Medicine. Obstetric Care Consensus No. 7: Placenta Accreta Spectrum. Obstet Gynecol. 2018;132(6):e259-e275.
American College of Obstetricians and Gynecologists. Committee Opinion No. 713: Antenatal Corticosteroid Therapy for Fetal Maturation. Obstet Gynecol. 2017;130(2):e102-e109.

Practice the NCLEX questions on this topic

3,200+ NCLEX questions with think-like-a-nurse rationales, unfolding case studies and adaptive readiness exams. Start with free practice questions, then choose a plan when you are ready.