Prenatal Development Timeline

  • 1 CE

    week 1- week 2

    Between these weeks you are not actually pregnant and you count your pregnancy from your last period
  • 3

    week 3- week 4

    Conception of the zygote that begins to turn into the blastocyst, specifically on week 4 blastocyst becomes embryo
  • 5

    week 5- week 6

    During these weeks the brain and spinal cord will develop along with the head, torso, arm limbs, and leg limbs. The umbilical cord will begin to form as well, while the heart continues to beat regularly.
  • 7

    week 7- week 8

    Between these weeks the ears, lips nose, and all major organs of the baby will be formed.
  • 10

    10

    In week 10 the head is 1/2 of the size of the body, All body parts are present and all the eyes, ears, arms, and legs should be identifiable. The baby also should be 1 1/4 inches
  • 11

    week 11

    During this week the genitals should be developed, while the head should be about half the length of the baby. Baby should also be around 2 inches, and weigh 1/3 oz.
  • 12

    week 12- week 13

    On week 12 the finger nails and face should be fully developed.
  • 14

    week 14- week 15

    Baby's gender will become identifiable, The baby should also be able to swallow and produce urine. Baby should be 3 1/2 inches, and
    1 1/2 oz.
  • 16

    week 16-17

    On week 16 the baby should be moving and be about
    4 1/2 inches, 4 oz.
  • 18

    week 18- week 19

    Through these weeks baby should be able to hear and their digestive system should be fully functionable.
  • 20

    week 20- week 21

    From week 20-21, Baby should have regular sleeping patterns. Baby's organs should all be formed and baby should be breathing. Baby can suck thumb at this point. Baby should also be 6 1/3 inches, 11oz, Also at this point baby is considered underdeveloped.
  • 22

    week 22- week 23

    At this stage baby's nails, finger prints, eyebrows, lashes, and possibly some hair should be present. baby should be more active and their heartbeat should be able to be heard by a stethoscope. Baby is at their lowest limit of viability and should be 7 1/2 inches, 11 oz.
  • 24

    week 24

    At this week baby's skin is translucent and their lungs are developed. Their sleep pattern should also be regular. They also should be 8 in an 1 1/2 lbs.
  • 28

    week 28- week 29

    During this stage baby's eyes should begin to open and close, Their lungs should also be able to breathe air. baby should be 10 inches and 2 1/4 lbs.
  • 31

    week 31- week 32

    AT this stage baby has finished major development and has rapid weight gain. Baby should be 3 1/2 lbs.
  • 34

    week 34

    At week 34 baby should respond to light, have finger nails/ toe nails, and should have smooth skin. Baby should also be 12 inches and 4 1/2 lbs.
  • 36

    week 36- week 37

    From this stage baby's head should be pointing towards the cervix.
  • 38

    week 38- week 40

    Between these final stages baby is considered full term from week 39 to week 40.