Week 21
Babies will now average 27.8 cm long and 430g weight. You might start to become aware of little kicks as your baby becomes stronger and more coordinated. She may be sucking her thumb! Inner ear bones and nerves are developing and she can start to detect sounds.

Week 22
Your baby will now be around 28.9 cm long and 501 g in weight. His finger and toe-nails will be emerging – hair will be energing on his scalp, and there will be eyebrows and eyelashes. His skin cells will be producing a protective layer of keratin.

Week 23
Babies (on average) will now be around 30 cm in length and around 600 g in weight. The cochlea in your baby’s inner ear is now developed, and he may start responding to loud sounds. He is also becoming familiar with your voice – so start talking to him a lot – it will start the bond between you. His lungs are now producing what’s called “surfactant” which supports the tiny air sacs (alveoli). This process strengthens the lungs in preparation for breathing after birth.

Week 24
Babies (on average) will be around 34 cm and weigh around 660g. You might even be being kept awake at night by your baby’s kicking, yawning and hiccuping inside of you! She will be starting to develop a cycle of sleeping and waking, which you will probably become aware of. She is starting to develop a primitive memory as her brain develops, and her brain waves are already similar to those of a newborn. Adult teeth buds are growing in her gums and her nostrils will be open by now. Her heartbeat wil have slowed to around 150-160 beats per minute by the end of this trimester.