Publication:

Efficacy of colour doppler imaging in prediction of placenta accrete

Background In present scenario of increasing cases of previous caesarean section the diagnosis of Placenta accreta preoperatively is of great value to the attending obstetrician. This helps in preparing, counselling the patient and also in assembling a multidisciplinary team for effective peripartum clinical management of these patients to prevent maternal morbidity and mortality.

Methods One hundred patient with persistent placenta previa after 28 weeks gestation were screened by grey scale B mode sonography. In suspicious cases of placenta accreta, further assessment by colour Doppler ultrasound was done. The color doppler imaging (CDI) criteria used were - diffuse intra parenchymal placental lacunar flow, focal intra parenchymal placental lacunar flow, bladder-uterine serosa interphase hypervascularity, prominent sub-placental venous complex and loss of sub-placental vascular signal in areas lacking peripheral sub-placental hypoechoic zone. Patients were prospectively followed up till delivery and the CDI findings were analysed with reference to final diagnosis made during caesarean section.

Results Six of hundred patients exhibited characteristic CDI patterns highly specific for placenta accreta according to the criteria used. In all 6 patients, morbidly adherent placenta was present intraoperatively. The sensitivity and specificity of CDI in the diagnosis of placenta accreta in presentstudy was 100%. Caesarean hysterectomy was required in five patients. Patients with CDI features of lacunar flow had higher incidence of blood loss, transfusion requirements and need for caesarean hysterectomy compared to patients with nonlacunar flow. The remaining 94 patients with placenta previa, not suspicious for placenta accreta on sonography underwent uncomplicated caesarean section.

Conclusions The use of CDI along with conventional grey-scale sonography improves the diagnostic accuracy for prediction of placenta accreta in patients with persistent placenta previa.