DIAGNOSTIC ACCURACY OF UTERINE ARTERY DOPPLER ULTRASOUND TO PREDICT PREECLAMPSIA IN PRIMIPAROUS FEMALES

Abstract

Objective: To determine the diagnostic accuracy of Doppler ultrasonography during second trimester of pregnancy, to predict pre-eclampsia (PE) in primigravidas.

Study Design: Cross sectional study.

Place and Duration of Study: MCH unit-II, Pakistan Institute of Medical Sciences Islamabad, from Apr 2015 to Oct 2015.

Material and Method: A total of 170 females were recruited for the study. Doppler ultrasound examination of the uterine artery (UA) was performed, using a color Doppler system. Doppler parameters including resistance index (RI) was calculated by the software supplied within the Doppler equipment. Females were labeled as positive if RI >0.7 and were labeled as negative if RI <0.7. Then females were followed till third trimester and were carefully monitored for pre-eclampsia. The data was entered on the pre-designed proforma. Collected data was entered and analyzed through SPSS version 16. A 2x2 table was generated to calculate sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of Doppler ultrasonography, taking development of PE as gold standard.

Results: The mean age of females was 27.46  4.67 years. The mean gestational age at time of recruitment was 20.95 ± 0.83 weeks. The mean height, weight and BMI of females were 1.66 ± 0.07meters, 72.85 ± 10.61kg and 26.63 ± 4.04kg/m2, respectively. There were 46 (27%) females who were obese while 124 (73%) females had normal BMI. At time of presentation of females, the RI on Doppler USG was >0.7 in 82 (48.2%) females while it was <0.7 in 88 (51.8%) females. There were 82 (48.2%) females who developed PE while 88 (51.8%) females did not develop PE at 20th week of gestation. Thus the calculated sensitivity, specificity, PPV and NPV of RI on Doppler USG were 85.4%, 86.4%, 85.4% and 86.4%. The overall diagnostic accuracy of RI was 85.9%.

Conclusion: Doppler USG is accurate enough that in future we can rely on this tool for prediction of PE in primigravidas.