Abstract
A prospective study was conducted in 49 first-trimester pregnancies—39 with live intrauterine pregnancies and 10 with missed abortions. Transvaginal sonography and color Doppler recorded size, sonographic appearance, color flow pattern, peak systolic velocity, and resistance index of each corpus luteum. Gray-scale sonographic appearances revealed thick-walled cysts, hypoechoic to isoechoic rounded structures, thin-walled cysts, and bilocular thick-walled cysts in patients with live intrauterine pregnancies. In patients with missed abortions, the most common pattern was thick-walled cysts, followed by hypoechoic areas and simple cysts. It was concluded that the corpus luteum, a well-identified structure in one of the ovaries in early pregnancy, has a wide range of sonographic morphologies. Better delineation is possible with color Doppler and color power angiography. Knowledge of the various morphological patterns on sonogram and color Doppler can help differentiate the corpus luteum from true ovarian pathologies.