What is the post partum risk associated with placenta praevia?

RML Lucknow - 2021

Obstetrics & Gynaecology

Medium

Appeared in: RML Lucknow - 2021

Explanation

Placenta praevia involves the implantation of the placenta in the lower uterine segment (LUS).
The LUS is anatomically different from the upper segment (fundus); it has fewer muscle fibers and greater connective tissue content.
After the delivery of the placenta, the uterus must contract strongly to constrict the blood vessels at the implantation site and prevent bleeding.
Due to its poor muscularity, the LUS cannot contract and retract effectively after delivery.
This failure of the uterus to contract is called uterine atony, which is the most common cause of postpartum haemorrhage (PPH).
Therefore, women with placenta praevia are at a significantly high risk for severe PPH.

Option A: While the risk of puerperal sepsis (infection) is increased, it is most often a secondary complication resulting from the high rate of cesarean sections required for placenta praevia, rather than a direct physiological consequence of the placental location.
Option C: Chronic hypertension is a pre-existing medical condition that can complicate pregnancy; it is not a postpartum complication caused by placenta praevia.
Option D: Disseminated Intravascular Coagulation (DIC) is a rare complication of placenta praevia. It is classically associated with placental abruption, where large amounts of thromboplastin are released into the maternal circulation, triggering a consumptive coagulopathy.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Postpartum complications associated with placenta praevia as background academic context rather than a clinical decision trigger.
Nurses must anticipate a high risk of postpartum haemorrhage (PPH) in any patient with a known diagnosis of placenta praevia.
Essential nursing preparations include ensuring at least two large-bore IV lines are in place, confirming the availability of cross-matched blood products, and having uterotonic medications (e.g., oxytocin, methylergometrine, carboprost) readily available for immediate administration after delivery.
Continuous monitoring of vital signs and vaginal bleeding is critical in the immediate postpartum period to detect and manage PPH promptly.

How to Approach the Question

First, identify the core clinical condition in the question: 'placenta praevia'.
Recall the definition and pathophysiology of placenta praevia: the placenta is implanted low in the uterus, over or near the cervix.
Think about the physiological process of the third stage of labor and the immediate postpartum period. The uterus must contract to control bleeding from the placental site.
Analyze the specific location of the placenta in praevia—the lower uterine segment (LUS). Recall that the LUS is less muscular and more fibrous than the fundus.
Connect the pathophysiology to the postpartum risk: A less muscular LUS cannot contract effectively, leading to uterine atony and a high risk of haemorrhage.
Evaluate the given options. Haemorrhage is a direct and major consequence. Rule out the other options: Infection is a secondary risk, chronic hypertension is a pre-existing condition, and DIC is more strongly associated with placental abruption.

Concept Tested & Keywords

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E6 Obstetrics Williams p. 71-94

E6 Midwifery Obstetrics and Gynecology Nursing Sandeep Kaur p. 18-26