Your baby weighs about 5.25 ounces (150g) and now measures 5 to 5.6 inches (12.5 to 14cm) from crown to rump. He is practicing breathing by gulping amniotic fluid into its lungs. This helps the lung's development so they will function at birth. Your baby may also be sucking his thumb.
Meconium is present in your baby's bowels. There is hair present on your baby's scalp and sweat glands are developing.
Your baby is becoming more sensitive to the outside world and is moving around, kicking and punching. As there is still plenty of space in your uterus, your baby can move around a lot, sitting cross-legged, reclining or even turning somersaults!
He can probably hear by now as the ossicles (the bones that pass sound to the inner ear) have hardened and the portion of the brain that receives signals from the brain is under development. Your baby is getting used to the sound of your heartbeat and blood passing through the umbilical cord, but may be startled by loud noises. Your baby is aware of some things in the outside world, including sounds and light. If you let the sun shine on your belly, your baby may be able to perceive a warm red glow.