RESUMEN
Objective: To determine the reliability of trans-abdominal ultrasonographical localization of placenta in cases of placenta previa major, by taking peroperative finding as gold standard
Study Design: Validation study
Place and Duration of Study: Maternity ward, Obstetrics and Gynecology department, Military Hospital Rawalpindi from 2007 to 2008
Patients and Methods: A total of 100 patients fulfilling the inclusion and exclusion criteria were recruited for the study. These patients were admitted to the maternity ward, where trans-abdominal ultrasound was performed, site of the placenta and its relation to the internal os was documented. These patients under went elective cesarean section, during which the site and relation of the placenta to the internal os was confirmed
Results: The mean age of patients was 34.23 +/- 6.76 years. Transabdominal ultrasound had a sensitivity of 93.4% in localizing major placenta praevia while the specificity was 83%. Positive predictive value was 94.7%, negative predictive value was 80% and accuracy 91%
Conclusion: Trans-abdominal ultrasound was found highly effective in diagnosing and localizing placenta previa