Evaluation of sonographic diagnostic criteria for placenta accreta.
OBJECTIVE
To compare the diagnostic value of reported sonographic criteria for placenta accreta and to develop a composite score system for antenatal evaluation.


METHODS
Sixty-six women at risk for placenta accreta were examined for 9 cases of placenta accreta that were confirmed at delivery. The performance of previously reported gray-scale and Doppler sonographic criteria for the diagnosis of placenta accreta was analyzed individually. A composite score system was developed by combining selected sensitive or specific sonographic criteria, and its performance was evaluated.


RESULTS
The criteria of obliteration of retroplacental clear space, a myometrial thickness of <1 mm, presence of vessels bridging placenta and uterine margin, disruption of the placental-uterine wall interface, and vessels crossing the sites of interface disruption showed a statistically significant association with placenta accreta. The disruption of the placental-uterine wall interface and the presence of vessels crossing these sites were the only 2 individual criteria that could distinguish placenta accreta from non-accreta, which could also be achieved by our composite score system using a cutoff value of 40, with a sensitivity of 89% and specificity of 98%.


CONCLUSIONS
The diagnostic performance of the sonographic diagnostic criteria used in the diagnosis of placenta accreta varies, and a composite score system improves the overall accuracy.
Wong
Hong Soo
HS
Department of Obstetrics and Gynaecology, School of Medicine and Health Sciences, University of Otago, P.O. Box 7343, Wellington, New Zealand.
Cheung
Ying Kei
YK
Zuccollo
Jane
J
Tait
John
J
Pringle
Kevin C
KC
D000328:Adult; D005260:Female; D006801:Humans; D010921:Placenta Accreta / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D011247:Pregnancy; D012680:Sensitivity and Specificity; D014463:Ultrasonography