What are the characteristics of bleeding in placenta previa?

Bihar CHO -2019

Obstetrics & Gynaecology

Easy

Appeared in: Bihar CHO -2019

Explanation

The hallmark sign of placenta previa is the sudden onset of painless, bright-red vaginal bleeding, typically occurring in the late second or third trimester.
The bleeding is painless because it results from the mechanical separation of the placenta from the thinning lower uterine segment and dilating cervix, which does not involve uterine contractions.
Unlike abruptio placentae, the uterus in placenta previa typically remains soft, relaxed, and non-tender between bleeding episodes.
The blood is bright red because it comes directly from the uteroplacental vessels and escapes through the cervix without significant delay or clotting.

Option B: Painful vaginal bleeding is the characteristic sign of abruptio placentae, where the premature separation of the placenta causes uterine tenderness and rigidity.
Option C: Bleeding is the cardinal symptom of placenta previa. While a concealed abruption can occur with no visible bleeding, placenta previa almost always presents with external bleeding.
Option D: This option is incorrect because the primary characteristic of bleeding in placenta previa is included as option A.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Clinical manifestations of placenta previa as background academic context rather than a clinical decision trigger.
A pregnant woman presenting with vaginal bleeding requires immediate assessment to determine the cause and ensure maternal and fetal stability. The distinction between placenta previa and abruption is critical for guiding management.
Patient Safety Alert: NEVER perform a digital vaginal or rectal examination on a pregnant woman with bleeding until placenta previa has been definitively ruled out by ultrasound. Such an exam can puncture the placenta and cause catastrophic hemorrhage.
What if? If the bleeding was accompanied by severe abdominal pain and a rigid, tender uterus, the diagnosis would shift to abruptio placentae. This is a true obstetrical emergency requiring immediate preparation for delivery, often involving management of hypovolemic shock and disseminated intravascular coagulation (DIC).

How to Approach the Question

First, identify the key term in the question: 'placenta previa'.
Recall the classic triad of symptoms for placenta previa: painless, sudden onset, and bright-red vaginal bleeding.
Mentally contrast these symptoms with those of its main differential diagnosis, abruptio placentae, which is characterized by painful bleeding and a rigid uterus.
Evaluate the options. 'Painless vaginal bleeding' directly matches the classic description of placenta previa.
Eliminate 'Painful vaginal bleeding' as it describes abruption. Eliminate 'No bleeding' as bleeding is the defining feature. This confirms the correct choice.

Concept Tested & Keywords

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E6 Obstetrics Williams pp. 71-95, 68-93