A growing fetus is pretty cool, and a lot of changes are happening right now. With the addition of about 4-6 ounces a week the baby is adding weight to her bones, organs, muscles and baby fat. With this increase in mass baby's face is gaining some fat and formed features are starting to develop along with eyelashes and eyebrows. She has grown some hair on her head as well, but it lacks pigment.
Baby's brain is also growing, and her brain wave patterns are similar to that of a newborn's. These developments help her process some of the sounds she can now hear inside the womb, like the gastric noises from your digestive system and your heartbeat. Baby can even hear your partner's voice and will recognize it from these early hearing days inside the womb once she is born. Her lungs are growing new branches and cells responsible for creating surfactant, the substance necessary to inflate her air sacs; both will be necessary for survival outside the womb.
Baby is also developing nerves and capillaries along her skin. The nerves will help relay sensations of touch back to her brain, and the capillaries will help transport blood to her developing structures. If you could see the baby right now, she would appear relatively translucent with visible organs beneath her skin. This translucent skin will change over the next few months as the capillaries and fat accumulate under her skin.
- American Pregnancy Association - Week 24
- Myo Clinic - Fetal Development Second Trimester