Outcomes of prospectively-collected consecutive cases of antenatal-suspected placenta accreta.
BACKGROUND
Accurate diagnosis of placenta accreta is tentative before surgery. This study developed a predictive score for antenatal diagnosis of placenta accreta through mathematical modeling using clinical signs.


METHODS
Antenatal cases of suspected placenta accreta were collected prospectively in a single-site tertiary delivery center. Women with clinical signs of placenta accreta (placenta previa, number of previous cesarean deliveries and/or ultrasound suspicion of placenta accreta) were included. The diagnosis of accreta was confirmed surgically. The primary endpoint was the proportion of surgically-diagnosed placenta accreta among all suspected cases. Logistic regression modeling was performed to assess preoperative risk factors for placenta accreta. The risk score was tested on a receiver operator characteristic curve to identify subjects with placenta accreta and the optimum cut-point was chosen.


RESULTS
Over nine years, 92 suspected accreta cases were identified from 46623 deliveries (0.2%). The diagnosis was confirmed at surgery in 52/92 cases (56%) and there were no maternal deaths. Blood transfusion requirements were greater in patients with placenta accreta versus patients without placenta accreta (median 7 [range 0-25, interquartile range 3-10] versus 0 [0-6, 0-2] units of blood, P <0.0001). Area under the curve of the receiver operator characteristic curve was 0.846, with contribution from three variables (placenta previa, number of previous cesarean deliveries and ultrasound suspicion), each with a P value <0.05. From the ROC curve a cut-point with 100% sensitivity and specificity 25% (95% CI 12.69%-41.20%) was achieved, compared with 86.6% sensitivity (95% CI 74.21%-94.41%) and 60.0% specificity (95% CI 43.33%-75.14%) using ultrasound alone.


CONCLUSIONS
Combining diagnostic features associated with placenta accreta through mathematical modeling has better positive predictive value than ultrasound alone.
Department of Anesthesiology and Critical Care Medicine, Hadassah Hebrew University Medical Center, Jerusalem, Israel. Electronic address: carolynfweiniger@gmail.com.
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Weiniger
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Einav
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Deutsch
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Ginosar
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Ezra
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D000328:Adult; D005260:Female; D006801:Humans; D016015:Logistic Models; D008962:Models, Theoretical; D010921:Placenta Accreta / Q000175:diagnosis*; D011247:Pregnancy; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity
Anesthesia; Hemorrhage; Modeling; Placenta accreta; Risk