Day 1: When conception (fertilization) occurs, the baby's features, including sex, hair and eye color, have already been determined.
9 Weeks: At this stage, the baby's heart has been beating since 18 days after conception and fingers and toes are developed.
10 Weeks: The baby hiccups and reacts to loud noises. The baby’s arms and legs are moving. There are 20 tiny tooth buds present in the gums. The eyelids are developing and begin to close.
12 weeks: The baby’s organs are completely developed. After this point, the baby is growing and gaining weight in preparation for birth.
18-20 Weeks: The baby's gender can be determined by ultrasound.
22 Weeks: At this stage, the baby's eyelashes can be seen and the lungs are developing. The pregnancy is about half over.
28 Weeks: The baby is about 11 inches long and weighs about 2.5 pounds. With the support of intensive care, a fetus born at this stage is capable of breathing air and the brain is developed enough to coordinate rhythmic breathing.