Ultrasound Evaluation of Vaginal Bleeding in First Trimester of Pregnancy: A Comparative Study with Clinical Examination

Introduction: Vaginal bleeding in the first trimester is a common obstetric situation ranging from an insignificant episode to life threatening emergency. The major causes are abortion, ectopic, and molar pregnancy. Ultrasonography is playing an increasing role in the diagnostic process. This study was taken up to evaluate its utility vis-a-vis clinical examination findings. Methods: This was a prospective study done at JSS Hospital Mysore, a tertiary care teaching hospital. All obstetric cases with a history of bleeding per vagina in the first trimester of pregnancy between November 2007 and September 2009 were included. A complete general physical and pelvic examination was done to arrive at a clinical diagnosis. Patients were then subjected to ultrasound examination. Clinical diagnosis and ultrasound diagnosis were correlated. Results: 165 of all obstetric cases (4247) had the first trimester bleeding (incidence of 4%). Commonest causes were abortion (83%), ectopic (13%), and molar pregnancy (4%). Of 165 cases, 106 cases were correctly identified by ultrasonography. 59 cases proved by sonography were misdiagnosed by clinical examination with a disparity of 64%. 46 cases were diagnosed by ultrasonography as viable pregnancies with sensitivity, specificity negative predictive value (NPV), and positive predictive value (PPV) of 100% and 98 cases were diagnosed as non-viable pregnancies by ultrasonography with sensitivity of 98%, specificity of 100%, and NPV of 98%. The clinical diagnosis had sensitivity of 82%, specificity of 52%, and PPV of 40% in diagnosing viable pregnancies. In diagnosing non-viable pregnancies, clinical diagnosis had a very poor statistical correlation with sensitivity of 50%, specificity of 81%, PPV of 62%, and NPV of 72%. Conclusion: This study reinforces results of earlier reports that ultrasound is a sensitive and specific non-invasive diagnostic tool in the evaluation of first trimester bleeding.