DIAGNOSTIC ACCURACY OF CEREBRAL-UMBILICAL RESISTANCE INDEX RATIO IN THE PREDICTION OF BIRTH ASPHYXIA
Background: Doppler velocimetry is a useful non-invasive investigation to assess the status of feto-placental circulation.
Cerebral Umbilical Resistance Index ratio is a useful predictor of birth asphyxia and adverse perinatal outcome.
The objective of the study was to determine the diagnostic accuracy of Cerebral Umbilical Resistance Index ratio in
the prediction of birth asphyxia.
Subjects and Methods: This was a cross sectional (Validation) study of 09 months duration (01/05/2012 to 31/01/2013)
conducted at Radiology department, Khyber Teaching Hospital, Peshawar. All pregnant ladies at high risk for birth
asphyxia, referred to Radiology department for Doppler ultrasound were recruited. Demographic characteristics were
recorded and C/U RI ratio was calculated for all patients and then they were followed at delivery. Of total 213 patients,
27 lost follow up and APGAR score of 186 new borns at 5 minutes of birth was recorded in a structured proforma.
Sensitivity, Specificity, Positive predictive value, Negative Predictive Value and Diagnostic accuracy of C/U RI for the
prediction of Birth asphyxia (low APGAR score) were calculated by cross tabulation using SPSS-16.
Results: The mean age of the patients was 30.25(±5.53 Sd.) years. Abnormal C/U RI ratio was found in 30% patients
on Doppler ultrasound, while APGAR score recorded at 5min of birth was low in 28.64%.The Sensitivity, Specificity,
PPV, NPV, and diagnostic accuracy of C/U RI ratio was found as 55.35%, 79.92%, 50.81%, 80% and 70.4% respectively.
Conclusion: Cerebral-Umbilical Resistance Index ratio is a very good predictor of low APGAR score and birth asphyxia
in women with high risk pregnancies.
Key words: Doppler, Cerebral-umbilical ratio, high risk pregnancies, APGAR score.