Clinical utility of sonography in the diagnosis and treatment of placental abruption.

OBJECTIVE: To determine the sensitivity and specificity of sonography for detection of placental abruption and whether sonographic results correlate with management or outcome.

METHODS: We identified 149 consecutive patients who underwent sonography at 24 weeks' gestational age or later for ruling out abruption or vaginal bleeding. Obstetric and neonatal data were obtained from the hospital perinatal database. Sonographic results, pathologic reports, and hospital charts were reviewed. Sonographic sensitivity, specificity, and positive and negative predictive values were calculated, and regression was used to determine independence of associations.

RESULTS: Of the 149 patients, 17 (11%) had sonographic evidence of abruption, and 32 (21%) had evidence of abruption at delivery. As the scan-to-delivery interval decreased, the positive predictive value increased and the negative predictive value decreased. Of 55 patients who gave birth within 14 days of sonography, 8 (15%) had scans consistent with abruption, and 29 (53%) had abruption at delivery; the sensitivity, specificity, and positive and negative predictive values of sonography were 24%, 96%, 88%, and 53%, respectively. Positive sonographic findings were univariately associated with 2- to 3-fold greater subsequent tocolysis, betamethasone use, duration of hospitalization, follow-up sonograms, preterm delivery, low birth weight, and neonatal intensive care unit admission. All but low birth weight and neonatal intensive care unit admission remained independently significant after adjustment for gestational age (P < .05).

CONCLUSIONS: Sonography is not sensitive for detection of placental abruption, but a positive finding is associated with more aggressive management and worse neonatal outcome.