Abstract :
The pregnancy is one of the most fascinating experiences which a
woman undergoes in her life and of the whole, the first trimester is a vital
time as the pregnancy gets established. The last menstrual period (LMP)
is generally used as a landmark for pregnancy dating, and the first
trimester of pregnancy is defined as 12 weeks after the LMP. The first
recognizable structure inside the gestational sac is the yolk sac, which
should be detectable as a regularly rounded extra-amniotic structure
when the gestational sac reaches dimensions of 8 to 10 mm. In a normal
pregnancy it should be possible to observe the yolk sac between 6-12
weeks of pregnancy or when it reaches 10 mm in size. Ultrasonography
shows the yolk sac as a round structure that is made up of an anechoic center bordered by a regular well-defined
echogenic rim. The normal shape of yolk sac is circular. The yolk sac appears at 6 weeks, thereafter increases in size,
attains its maximum diameter at 10 weeks and then it starts decreasing in size. It disappears at 12 weeks.
Aim and Objectives of the present study is to study the shape of yolk sac in pregnant females, in the first trimester of
pregnancy and to find it's correlation with spontaneous abortion.
We studied 72 pregnant females, who were in their first trimester of pregnancy, referred by Department of Obstetrics
and Gynaecology. The shape of yolk sac was observed by transvaginal sonography and its correlation with
spontaneous abortion was studied.
Yolk sac was present in 70 cases (97.22%) and in two cases (2.78%), it was absent. In 68 (97.14%) cases the shape of
yolk sack was circular. It was irregular (1.4%) and oblong (1.4%) in one case each.
Keyword :
Yolk sac, Pregnancy, Yolk sac shape, Transvaginal sonography, Spontaneous abortion.