ABSTRACT
This study was carried out on 445 patients in the first trimester of pregnancy. They had one or more risk factors for abortion. History and clinical examination were done and abdominal ultrasonographic examination was carried out on day 43 to 56, 57 to 70 and 71 to 84 of the estimated gestational age [EGA]. At the end of the first trimester, the results showed that the total incidence of abortion was 17.5%. The three ultrasonic examinations showed that the incidence of abortion was very high when the shape of gestational sac [GS] was irregular, followed by the dumbbell shape and when the average diameter of GS or crown-rump length [CRL] was shorter or longer than that of equal to EGA. Measurement of CRL on day 71 to 84 was accurate in prediction of first trimester abortion. It is concluded that ultrasound examination is accurate in predicting first trimester abortion. If EHM is not seen by day 71 to 84 of EGA, missed abortion should be considered. For patient at risk of abortion, ultrasound examination is recommended to be carried out as early in pregnancy as possible and to be repeated-within two weeks for three times