04/04/2026
By 33 weeks, your baby is practically a "little human" in terms of behavior and appearance. While a 20-week scan shows the structural development, a 33-week scan is often more about the personality and facial expressions, as the baby now has enough fat under the skin to make their features look very similar to how they will appear at birth.
Why You See So Many Expressions
At this stage, the brain’s neural pathways are rapidly connecting, allowing the fetus to coordinate complex facial muscles. You are likely seeing:
The "Practice" Smile: While often attributed to gas or reflex after birth, in the womb, these are practice runs for social signaling.
Grimacing & Pouting: Baby may be reacting to the taste of the amniotic fluid (which changes based on what you eat!) or a poke from the ultrasound transducer.
Eye Movements: They are likely blinking and even moving their eyes as if in REM sleep, suggesting they may be dreaming.
Rooting & Sucking: You’ll often see them sucking a thumb or "searching" with their mouth, which is a vital survival reflex for breastfeeding.