The clinical significance of examining yolk sac by B-mode ultrasonography in the first trimester pregnancy

Objective To study the relation between the size of yolk sac and the outcome of pregnancy, an examination of ultilizing B - Mode ultrasonography to monitor the diameter of yolk sac was done. Methods Using Trans - abdomenal and Transvaginal ultrasound to examine 262 women who are in early pregnancy, the relation between the yolk sac's state of normal and the outcome of pregnancy is observed. Results Among all 198 normal pregnancy women,everyone's yolk sac is completely observed. Yolk sac's growth is correlated with the pregnancy week.From the 5th to the llth week, it grows continuously and regularly. Then it begins to shrink from the 12th week. At last,it disappears in the 13th week. The size of yolk sac is clearly different between normal pregnancy and abnormal pregnancy(P 0.05) . Conclusion It should have an important clinic valne in forecasting the prognosis of pregnancy by B - mode ultrasonography to monitor the size of yolk sac in the pregnancy.