Prognostic significance of secondary yolk sac assessment by transvaginal ultrasonography as a predictive method of pregnancy outcome

ABSTRACT

This study was designed to evaluate the prognostic significance of transvaginal ultrasonography measurement of the yolk sac in early pregnancy and its significance as a predictive method for pregnancy outcome. The study composed of 60 consecutive first trimester singleton pregnancies to evaluate size abnormalities of the secondary yolk sac [YS] vis-a-vis pregnancy outcome using transvaginal sonography [TVS]. In normal pregnancy outcome [NPO], the YS diameter showed an increase from the 5th to the 11th week, menstrual age, followed by a decrease and its disappearance after 12 weeks. A yolk sac of abnormal size was statistically significant in spontaneous abortion [SA] versus NPO with a sensitivity of 66.3%, a specificity of 99%, a positive predictive value of 91.6% and a negative predictive value of 95.2%. These preliminary results indicated that very early measurements of the YS in gestation may be a useful marker of pregnancy outcome: