Picture of First Trimester (12 Weeks)
A baby in the first trimester at 12 weeks has the following features:
- Muscles and nerves are coordinated. Baby can make a fist.
- The baby's eyelids are closed and will not open until 28 weeks' gestation.
- The growth of the head is slower and the baby has grown longer. Your baby weighs nearly one ounce and is about 3 inches long.
- The external sex organs show the baby's gender, but this is not distinguishable on ultrasound until the second trimester or later.
Text Reference: American Pregnancy Association: “Fetal Development: First Trimester”