Accuracy of Ultrasounds in the Diagnosis of Placenta Previa by Nonradiologists in Cameroon

Abstract

Objectives: Ultrasound evaluation could ensure early diagnoses prior to the onset of clinical manifestations. The use of ultrasound as a diagnostic tool for varying disease states is gaining ground in Africa; however, its operator dependence constitutes a major setback. Our main goal was to evaluate the accuracy of ultrasound in the diagnosis of placenta previa (PP) in Cameroon, and especially its use by nonradiologists. Materials and methods:We carried out a cross-sectional prospective study in the maternity unit of the Yaoundé Central Hospital during a period of 13 months (December 1, 2014 to December 31, 2015. Our study population involved women with prior cesarean section irrespective of the indication at least 28 weeks of gestational age. During surgery the diagnosis was confirmed. We included all women with a past history of cesarean section who underwent a 3rd trimester ultrasound scan (USS), especially in the last 4 weeks preceding the cesarean section. Results:The mean age of our study population was 28.02 years (± 6.13 years), with age extremes at 13 and 44 years respectively. Out of 761 women who underwent cesarean section, 153 had been diagnosed preoperatively with PP. All the USSs were transabdominal. Third trimester scans irrespective of the operator had a sensitivity of 82, and 99% specificity. Among the operators, radiologists and obstetricians had the best sensitivity rates (83 and 81% respectively) as against 71.4% among other operators. Conclusion:Ultrasound scanning is important in the antenatal period as a diagnostic tool for PP when carried out by radiologists and obstetricians. Routine use of the transvaginal and transperineal routes should be encouraged so as to gain in accuracy during 3rd trimester scanning. However, the nonradiologists need to be trained because of the accuracy lapses involving the USSs which they carry out.