The mean Gestational sac diameter
Weeks
GS diameter (cm)
5.0
1.0
5.5
1.3
6.0
1.7
6.5
2.0
7.0
2.4
7.5
2.7
8.0
3.1
8.5
3.4
9.0
3.8
9.5
4.1
10.0
4.5