[Value of prenatal diagnosis of placenta previa with placenta increta by transabdominal color Doppler ultrasound].

Objective: To assess the value of prenatal diagnosis of placenta previa with placenta increta by transabdominal color Doppler ultrasound.

Methods: Two hundred and fourteen patients with persistent placenta previa underwent transabdominal color Doppler ultrasound for the prenatal diagnosis of placenta increta in our hospital from June 2002 to June 2005. We prospectively followed up their clinical and pathological results. The main color Doppler imaging criteria used included a loss of the normally visible retroplacental hypoechoic zone and/or a lacunar flow pattern showing marked or turbulent blood flow distributed within the subplacenta or intraparenchymal placenta area and extended into the surrounding tissues.

Results: (1) The sensitivity of color Doppler ultrasound in diagnosis of placenta previa increta was 77.3% (17/22) and the specificity was 98.4% (189/192). The positive and negative predictive values were 85.0% (17/20) and 97.4% (189/194) respectively. (2) The morbidity of placenta increta in women with placenta previa was 10.3% (22/214). The average amount of peripartum hemorrhage of placenta previa with increta (2494 ml) was higher than that of placenta previa without increta (505 ml). The morbidity of cesarean hysterectomy among women with placenta previa increta was 40.9% (9/22).

Conclusion: Placenta previa is a high-risk factor of placenta increta. Placenta previa increta threatens the lives of the mother and the fetus because of massive hemorrhage. Prenatal color Doppler ultrasound has a high sensitivity and specificity for the identification of placenta previa increta. It has a positive impact on the peripartum clinical management of the affected patients through reducing the death of the mother and the fetus because of unpredictive bleeding while terminating the pregnancy.