Fetal Develoment

  • Week 6

    Week 6
    This week's major developments: The nose, mouth, and ears that you'll spend so much time kissing in eight months are beginning to take shape. If you could see into your uterus, you'd find an oversize head and dark spots where your baby's eyes and nostrils are starting to form. His emerging ears are marked by small depressions on the sides of the head, and his arms and legs by protruding buds. http://www.babycenter.com/6_your-pregnancy-6-weeks_1095.bc
  • Week 16

    Week 16
    Get ready for a growth spurt. In the next few weeks, your baby will double his weight and add inches to his length. Right now, he's about the size of an avocado: 4 1/2 inches long (head to rump) and 3 1/2 ounces. His legs are much more developed, his head is more erect than it has been, and his eyes have moved closer to the front of his head. His ears are close to their final position, too. The patterning of his scalp has begun, though his locks aren't recognizable yet.
  • Week 20

    Week 20
    Your baby weighs about 10 1/2 ounces now. He's also around 6 1/2 inches long from head to bottom and about 10 inches from head to heel — the length of a banana. (For the first 20 weeks, when a baby's legs are curled up against his torso and hard to measure, measurements are taken from the top of his head to his bottom — the "crown to rump" measurement.
  • Week 24

    Week 24
    Your baby's growing steadily, having gained about 4 ounces since last week. That puts him at just over a pound. Since he's almost a foot long (picture an ear of corn), he cuts a pretty lean figure at this point, but his body is filling out proportionally and he'll soon start to plump up. His brain is also growing quickly now, and his taste buds are continuing to develop.
  • Week 27

    Week 27
    This week, your baby weighs almost 2 pounds (like a head of cauliflower) and is about 14 1/2 inches long with her legs extended. She's sleeping and waking at regular intervals, opening and closing her eyes, and perhaps even sucking her fingers. With more brain tissue developing, your baby's brain is very active now. While her lungs are still immature.
  • Week 9

    Week 9
    She's starting to look more and more human. Her essential body parts are accounted for, though they'll go through plenty of fine-tuning in the coming months. Other changes abound: Your baby's heart finishes dividing into four chambers, and the valves start to form — as do her tiny teeth. The embryonic "tail" is completely gone. Your baby's organs, muscles, and nerves are kicking into gear. The external sex organs are there but won't be distinguishable as male or female for another few weeks.
  • Week 12

    Week 12
    The most dramatic development this week: reflexes. Your baby's fingers will soon begin to open and close, his toes will curl, his eye muscles will clench, and his mouth will make sucking movements. In fact, if you prod your abdomen, your baby will squirm in response, although you won't be able to feel it. His intestines, which have grown so fast that they protrude into the umbilical cord, will start to move into his abdominal cavity about now.