Combined Clinical and Ultrasonographic Work-up for the Diagnosis of Retained Products of Conception

Retained products of conception (POC)—a relatively common finding after vaginal and cesarean delivery as well as termination of pregnancy—is a major diagnostic challenge. Sonohysterography has been shown to diagnose retained POC with nearly a 100% success rate, but has a number of drawbacks including the need for special equipment and considerable operator experience, its invasiveness, and high cost. Ultrasonography is a common part of the gynecologic examination and widely available but has not been useful for diagnosis of retained POC. However, with improved ultrasonographic technology and experience with its use, transvaginal sonographic (TVS) evaluation has shown increasing promise for retained POC diagnosis. The investigators conducted a retrospective chart review to assess the accuracy of an evaluation protocol based on clinical treatment with uterotonics combined with TVS evaluation for the detection of retained POC. The participants were 339 women referred to an obstetrics ultrasound unit because of abnormal bleeding, fever, abdominal pain, or a combination of these symptoms after labor or pregnancy termination. Upon enrollment, all participants underwent a TVS evaluation and were divided into 2 groups: one with negative TVS results and the other with positive results. Patients with negative results were discharged and instructed to return to the hospital if bleeding, abdominal pain, or fever recurred. Those with positive results were treated conservatively with methyl ergometrine for 5 days and reexamined with TVS. Patients with positive results in the second TVS evaluation were referred for curettage and pathological examination of the uterine content. The sensitivity, specificity, and positive and negative predictive values were determined for the total cohort. A total of 269 patients (79.4%, 269/339) were negative for retained POC and were discharged. The remaining 20.6% (70/339) with positive results received conservative treatment with methyl ergometrine and were reeval- uated with TVS. For 33 (47.1%) of the 70 positive patients, the results were negative at the second TVS, leaving 37 patients who remained positive. These 37 positive patients and an additional 2 (0.07%) who had been negative initially but were revaluated because of recurrent bleeding underwent uterine curettage. The sensitivity for identifying retained POC with TVS was 94% and the specificity was 98%; the positive and negative predictive values were 84% and 99%, respectively. These findings indicate that that the proposed protocol provides an accurate and highly sensitive diagnosis of retained POC that may help avoid unnecessary surgery in nearly 50% of women with suspected retained POC after labor or abortion.