5 Weeks

Yolk sac noted within gestational sac.

6 Weeks

Foetal pole and yolk sac noted within gestational sac. Foetal cardiac activity can be seen.

7 Weeks

Foetal shape can be identified and Number of foetuses can be confirmed

7 Weeks (Twin Pregnancy)
9 Weeks

Small limb buds noted within the foetus.

10 Weeks

Limb buds can be clearly visualized.

13 Weeks

Foetal head, body and limbs can be clearly visualized.Nasal bone, Nuchal translucency can be measured and gross foetal abnomality can be diagnosed.

17 Weeks
From 19 Weeks to 22 Weeks
18-22 Weeks is the time for second trimester anomaly scan. Almost 70-80% abnormality can be diagnosed.
19 Weeks
20 Weeks

Limb abnormality can be diagnosed eg, club foot

21 Weeks

Facial abnormality can be diagnosed eg, hare lip & cleft palate.

22 Weeks

Foetal echo is best between 22-24 weeks

24 Weeks
26 Weeks

As pregnancy advances foetal facial details are better visualized.

27 Weeks
29 Weeks
31 Weeks
32 Weeks
34 Weeks
40 Weeks