SBA — Single Best Answer · Review
Question 162
Delivery suite → Haemorrhage
Classification
Question
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A woman at 36 weeks presents with sudden abdominal pain and a small amount of vaginal bleeding. Her uterus is tender and persistently tense. CTG shows fetal tachycardia with recurrent decelerations. Ultrasound demonstrates an anterior placenta clear of the cervix but no retroplacental collection. Kleihauer testing is negative. Which combination of findings should carry the greatest diagnostic weight?
Question Stem
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Options
A
Negative ultrasound and negative Kleihauer test, making abruption unlikely
B
Small measured blood loss and absence of placenta praevia, making a cervical cause most likely
C
Negative Kleihauer test and normally located placenta, excluding a placental cause
D
Absence of a visible retroplacental clot, requiring another diagnosis before treatment
E
Pain, uterine hypertonicity and fetal compromise, supporting a clinical diagnosis of placental abruption despite negative investigations
Explanation
Placental abruption is fundamentally a clinical diagnosis. Sudden pain, uterine tenderness or hypertonicity and fetal compromise provide a compelling clinical constellation even when external bleeding is limited. Ultrasound has poor sensitivity for retroplacental clot, so a negative scan cannot exclude abruption. Likewise, the Kleihauer test is used to quantify fetomaternal haemorrhage for anti-D management in RhD-negative women and is not a diagnostic test for abruption. The question therefore requires integration of the clinical findings rather than allowing two low-exclusion-value investigations to overrule a strongly suggestive presentation.
Option Validity
A) Neither a negative ultrasound nor a negative Kleihauer test reliably excludes placental abruption.
B) Visible blood loss may substantially underestimate concealed haemorrhage, and exclusion of placenta praevia does not establish a cervical source.
C) A normally located placenta does not exclude placental abruption, and Kleihauer testing is not a diagnostic test for abruption.
D) Necessary management should not be delayed awaiting imaging confirmation when the clinical presentation strongly supports placental abruption.
Further Reading
RCOG Green-top Guideline No. 63. Antepartum Haemorrhage. Royal College of Obstetricians and Gynaecologists; 2011.