Sonographic findings and clinical correlations in molar pregnancy.

From a group of 313 women referred for pelvic sonography because of clinical suspicion of molar gestation and 5 additional sonographically diagnosed but clinically nonsuspect cases of hydatidiform mole, 50 were ultimately proved to have a hydatidiform mole. There were 2 false-positive and 2 false-negative sonographic interpretations. In the 50 patients having a proved molar gestation, predelivery uterine volume was sonographically calculated, and the presence and size of theca lutein cysts was recorded. Correlation of gestational age estimated from sonographically measured intrauterine volume to clinical estimation of uterine size revealed a tendency to overestimate gestational size by a mean of 3.5 weeks. Theca lutein cysts were detected in 10% of patients by clinical examination, whereas they were detected by sonography in 37% of cases. Seven of 50 molar pregnancies were associated with post-molar trophoblastic disease. Patients with a volumetrically large-for-dates uterus or with theca lutein cysts did not have a higher incidence of postevacuation invasive mole or choriocarcinoma. Sonography remains an excellent diagnostic technique, but cannot predict the postevacuation clinical course.