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Question 192
Delivery suite → Haemorrhage
Classification
Question
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A screening proposal is designed to prevent placental abruption by identifying women with recognised antenatal risk factors and classifying all remaining pregnancies as negligible risk. Which feature of the epidemiology of abruption most fundamentally limits this strategy?
Question Stem
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Options
A
Placental abruption occurs only after the onset of hypertension
B
Ultrasound screening detects most abruptions before symptoms occur
C
The majority of risk factors become relevant only after delivery
D
Placental abruption is restricted to women with a previous abruption
E
A substantial proportion of abruptions occur in women without identifiable antenatal risk factors, limiting prediction by risk-factor screening
Explanation
Recognised risk factors can identify women at increased probability of placental abruption, but they do not provide an effective rule-out strategy. A substantial proportion of abruptions occur in women who were previously considered low risk. Consequently, absence of recognised risk factors cannot be interpreted as negligible risk, and APH symptoms must be assessed on their clinical merits regardless of the woman's prior risk profile. This distinction between risk association and predictive performance is central to understanding why abruption cannot be reliably prevented or anticipated through risk-factor screening alone.
Option Validity
A) Hypertension is an important association but abruption is not confined to hypertensive pregnancies.
B) Ultrasound is not an effective screening method for predicting abruption and has poor sensitivity even for detecting retroplacental clot after presentation.
C) Recognised risk factors are clinically relevant antenatally, but their predictive ability is limited.
D) Previous abruption markedly increases recurrence risk but most cases are not restricted to women with that history.
Further Reading
RCOG Green-top Guideline No. 63. Antepartum Haemorrhage. Royal College of Obstetricians and Gynaecologists; 2011.