Evaluation of new ultrasound parameters in the diagnosis of placenta accreta spectrum in placenta previa

Objective: To determine placenta previa accreta using ultrasound anatomical features and Doppler flowmetry profile. Methodology: Descriptive, prospective, cohort, longitudinal study. The European Working Group on Abnormally Invasive Placenta (EW-AIP) classification was used. Institution: Hospital Nacional del Sur de EsSalud, Arequipa, Peru. Participants: Pregnant women at high obstetric risk with diagnosis of placenta previa, 20-40 weeks of gestation with diverse parity and history of cesarean section. Results: Out of 90 patients with a diagnosis of placenta previa in 2022 and 2023, 12 patients with suspected accretism were selected by ultrasound assessment and Doppler flowmetry. Maternal age, number of gestations, history of uterine curettage, previous cesarean section and greater number of cesarean sections were statistically significant, with the second and third cesarean section presenting 21.1 and 9.6 times more risk of accretism, respectively. Ultrasonographic criteria were loss of the clear zone, irregular oval placental lacunae, disruption of the bladder wall, placental heterogenicity and hyperechogenicity, hyperechogenic and irregular chorionic plaque, hypervasculature of the bladder and subplacental wall, nutritional vessels and hypervascularized placental lacunae. The peak flow velocity of 52.3 cm/ sec was highly significant for placental accreta vs. 26.0 mL/sec in placentas previa with no signs of accreta. Doppler flow velocity above 50 cm/sec presented higher risk of placenta accreta and decreased maternal survival. Conclusion: In the study, the ultrasound findings of a) placental heterogenicity and hyperechogenicity, b) hyperechogenic and irregular chorionic plaque, and c) Doppler flowmetry quantified with the maximum velocity were useful in predicting placental accretency.