Sonographic evaluation of the puerperal uterus: correlation with manual examination

To document uterine involution after vaginal delivery and cesarean section by abdominal sonography and to compare the efficacy of manual examination and ultrasonography.

Postpartum manual and sonographic assessment of uterine involution was performed in 120 patients following vaginal and cesarean delivery with an attempt to build a database of changes in uterine dimensions. The patients' reports on the intensity of uterine contractions and vaginal bleeding were compared to the results of sonographic imaging.

Palpation revealed proper uterine involution in 80 and 25% of patients after vaginal delivery and cesarean section, respectively. It could not be performed in 2.5% after vaginal delivery compared to 50% after cesarean section. Uterine length was found to be significantly greater after cesarean section than after vaginal delivery (p = 0.0001), and the anterior uterine wall was significantly thinner than the posterior wall (p = 0.0001). Uterine length was significantly greater in the presence of blood accumulation in the uterine cavity (20.7 cm), than when the uterus was empty (18.8 cm) (p = 0.001). In correlating between the patient's report of intense bleeding and the sonographic picture of blood in the uterine cavity sonography had a sensitivity of 0.56 and a specificity of 0.83, whereas the patients' reports had a positive predictive value of 0.22. The difference in information provided by the patients versus that provided by sonography was highly significant (p = 0.001, chi(2) test).

Within 3 days after delivery, patients particularly those having had a cesarean section, should undergo uterine sonographic scanning and manual palpation to evaluate involution and presence of blood in the uterine cavity.