Table 8. Correlation between yolk sac diameter in first trimester scan and biparietal diameter(mm), abdominal circumference (mm) femur length (mm), estimated fetal weight (gm) gestational age by us (weeks) amniotic fluid index(mm) in the second trimester scan.
Yolk sac 2-5mm
(n=87)
Yolk sac >5mm
(n=27)
t-test p-value
Biparietal diameter(mm)
Mean±SD
Range
41.35±10.14
29-a82
43.99±13.33
29.1-a82
0.973


0.326


Abdominal circumference (mm)
Mean±SD
Range
126.81±34.90
82-a201.8
139.73±40.62
82-a201.8
2.090


0.151


Femur length
Mean±SD
Range
32.24±30.20
18-a299
31.50±8.94
19.1-a48
0.012


0.913


Estimated fetal weight (gm)
Mean±SD
Range
296.53±172.63
110-a820
360.85±208.52
138-a730
2.078


0.152


Gestational age on US (weeks)
Mean±SD
Range
18.20±2.69
15-a24
19.05±3.12
15-a24
1.531


0.219


Amniotic fluid index (mm)
Mean±SD
Range
136.44±36.12
77.1-a228
137.00±47.28
11-a220
0.003


0.954


T-Independent Sample t-test; p-value >0.05 S.