Summary:Endovaginal sonography (EVS) and endovaginal color flow doppler (EVCFD) provide reliable, clinically relevant information in first trimester ultrasound diagnosis. The advent of EVS and EVCFD has resulted in earlier and more accurate diagnosis of ectopic pregnancy and embryonic demise. Abnormal endovaginal sonographic features may also be used to predict abnormal outcome in live, otherwise normal appearing embryos. EVS and EVCFD are also helpful in the early diagnosis of gestational trophoblastic disease and fetal anomalies (depending on the developmental stage).