Around week 15, your little fetus is about the size of an apple or navel orange weighing about 2.5 ounces and measuring approximately 4 inches from top to bottom. Your fetus is growing eyelashes and eyebrows, and the soft downy hair on her head is becoming coarse and gaining the pigment, they'll have when born. Your fetus can hear muted outside the womb sounds of your voice and is comforted by noise from mom's digestive system and heart.
Your little one's brain is now controlling all the muscles in her body, including practicing facial expressions like frowning, squinting, wincing, and grimacing. These faces don't indicate her mood, but it is the practice that helps develop muscle strength and coordination. The baby is also moving around now that she can freely move all her limbs and joints. You probably won't feel it yet, but you can bet she is busy stretching, flexing, and even doing somersaults and flips. With this new muscle control, she will also start practicing breathing, sucking, and swallowing in preparation for life “on the outside.”
Reference Source
- American Pregnancy Association - Pregnancy Week 15
- WebMD - Week 15
- Mayo Clinic - Fetal development: The 2nd trimester