Weeks 13-16 Second Trimester and Fetal Stage
I am really growing! I am about 5 inches long now. My head is a third of my entire length. My extremely sensitive brain needs room to grow so my skull consists of large, bones that are loosely connected so the brain has room to expand. My nervous system is operating and my muscles respond to stimulation from my brain, so I can coordinate my movements.
Although I don’t breathe air yet, it’s time to practice my breathing movements. This builds my muscles so that I will be able to breathe once I am born. I even get the hiccoughs once in awhile.
My gender, determined at conception, will be evident soon.
I have little nails beginning to form on the fingers, and fuzzy stuff called hair on my head and on my eyebrows. I even have extra fine hair on my skin to help me to regulate my body temperature.
My nose, chin, and lips are becoming well developed which allows me to have facial expressions. My teeth are growing underneath my gums but will stay there even after I am born. The inside structures of my ears are formed and I am beginning to hear strange sounds that I think are my mommy’s tummy and heartbeat.
My sucking reflex is developing which will enable me to nurse someday.