Résumé
This study was performed on 100 pregnant women during the first trimester. They were divided into three groups. First group included 40 high-risk cases with a history of recurrent abortion. Second group included 40 low-risk cases with no history of recurrent abortion, but with current threatened abortion. Third group included 20 normal control cases. Transvaginal US examination was done to measure the mean sac diameter [MSD], crown- rump length [CRL] and embryonic heart rate [HER] and to study the uterine artery color Doppler indices. The outcome of pregnancy in each case was observed and its relation with the measured parameters was examined. Only one transvaginal US examination showing normal MSD, CRL and EHR is very reassuring and should be sufficient for the first trimester. However, the finding of an abnormal US parameter should necessitate a repeated US examination a week or ten days later. Slow EHR was the most accurate single US parameter in predicting spontaneous abortion. Decreasing uterine artery resistance index [RI] and pulsatility index [PI] with gestation was a good predictor of favorable outcome, but the reverse was not true. The use of a combination of more than one parameter was more predictive than any single parameter