Fetal Development Timeline

  • Fetal Development Week 1

    Fetal Development Week 1
    Week 1 is the beginning of fetal development. It starts with your last menstrual cycle which starts off the 9 month countdown to childbirth.
  • Fetal Development Week 2

    Fetal Development Week 2
    At this point the uterus is forming a thick lining made out of blood vessels called the endometrium. This lining will be a sac used to cusion and hold the fetus throughout pregnancy. The egg is being released into the falopian tube to begin ovulation. The egg will mature and meet with one of the 350 million sperm cells and immediately shut down, not letting any more sperm in.
  • Week 3

    Week 3
    At this point the egg will start dividing and travel into the uterus from the falopian tube. The egg will immediatley become either a male or female and has all of the DNA needed to become a person. It has 46 chromosomes and is continuing to divide and grow.
  • Week 4

    Week 4
    At this point the embryo is in the uterus and after 3 days it (Since it already knows its gender, let's say it's a girl and her name is Avary. Get it? Ava and Ovary?) burrows herself into the lining of the uterus, the endometrium. Now Avary is a blastocyte, a fluid filled cluster of 50 to 60 cells and is continuing to multiply.
  • Week 5

    Week 5
    At this stage Avary is continuing to grow rapidly. The cells that make up the ovum are now differentiating into specialized cells that make up the embryo, placenta, amniotic sack, etc. Avary is also starting to release hormones that stop the menstrual cycle from happening. No more periods!
  • Week 6

    Week 6
    Avary is now 8mm! How exciting! The body is beginning to definitely take shap, with details such as the spinal chord closing, blood vessels forming, a heart beginning to form, and the brain splitting into 5 parts! Avary is quickly developing, so her mommy is very tired a lot!
  • Week 7

    Week 7
    We're getting a beat! Avary's heart is now beating with one chamber. There are other developments such as arms and legs and major organs such as the kidney, liver, heart, lungs, and spleen. Avary is also just about 13mm. The neural tube closes which starts the feeling of pregnancy such as nausea, fatigue, and sore breasts.
  • Week 8

    Week 8
    There's definitely a baby in there! Avarys toes are starting to come in, she's starting to practice moving, and her face is coming in! THis is also the time of the first paternal test, and also the longest. Let's hope she's healthy!
  • Week 9

    Week 9
    Avary just grew past an inch! (1.2 to be exact) . The arms and legs are starting to lengthen and Avary is now swimming in a bag of fluid (Sounds fun huh?)
  • Week 10

    Week 10
    Avary is officially a fetus! She is the size of a small strawberry and features such as the neck, hair, nipples, fingerprints, and ears are starting to develope
  • Week 11

    Week 11
    Avary now has seperate toes and fingers! SHe now has taste buds, the whole body is sensitive to touch, and her cartilage is now turning into bone. The brain is continuing to develope and is producing 250,000 nerve cells a minute. She is also the size of a small plum!
  • Week 12

    Week 12
    She now has facial features! Her fingernails and toe nails are also coming in. At this point the mother can have her week 12 scan and she will see Avary moving a lot!
  • Week 13

    Week 13
    Avary now has insulin! She is moving in a jerky fasion but her mother can't yet feel that (She is still only about 2 inches). Now instead of developing, Avary will be focusing on growing.
  • Week 14

    Week 14
    Avary's kidneys are now producing urine and she is now peeing into the amniotic fluid around her (Yuck). She is now about 3 and a half inches and her bones are getting stronger by the day. ANd ahe also really looks an alien.
  • Week 15

    Week 15
    Avary is now 4 inches but is still very skinny. Her limbs are starting to really lengthen out and you may be able to feel her moving! Also her adult taste buds are formed so she ca even savor her mothers food!
  • Week 16

    Week 16
    Avary is now 5 inches and weighs 3.5 ounces. SHe is now a breather! She can now grasp things and kick and even do summer saults! It's like a little part down there! Her mother is also starting to show more.
  • Week 17

    Week 17
    Avary's has to squint er eyes in the sunlight now! She should also consider excercizing more because she is starting to accumulate fat.
  • Week 18

    Week 18
    Avary is now half a foot and weighs 7 ounces! ANd you better crank up the Modest Mouse because she can hear noise now and she needs to get started right. Alvioli have formed in the lungs. She's beginning to cry, but luckily the crying doesn't make noise due to no oxygen.
  • Week 19

    Week 19
    Avary is now 6 and a half inches and weighs 9 ounces, and the placenta is continuing to grow and nourish her. Her heart is now visible and oh boy her locks are comin in!
  • Week 20

    Week 20
    Avary is now 7 inches, 11 ounces.Her skin is getting thicker and you better watch your potty mouth because she can recognize your voice. This is also an important time for sensory development.
  • Week 21

    Week 21
    Avary is now 10.5 inches and 12.7 ounces. Her bone marrow is cookin up blood vessels! Her small intestine is now starting to absorb sugars.
  • Week 22

    Week 22
    Avary is now 11 inches and weighs about a pound. You better keep the volume down because she reacts to loud noises. And boy oh boy her eyebrows are on fleek!
  • Week 23

    Week 23
    Avary is at just about a foot at 11 inches. She can suck now and already wants gains so she is doing baby workouts. If Avary got restless, sh'd have a 20% chance of survival.
  • Week 24

    Week 24
    Avary hit a foot! And weighs 1.3 pounds. Her lungs are developing (respiratory branches, so on...) and her eyelids are clearly seen. She's also starting to suck her thumb!
  • Week 25

    Week 25
    Avary weighs 1.5 pounds and is 13.5 inches. Her bones are fully solid and her sexual organs are completely developed, She can now clasp things, so if your phone goes missing you'll know why.
  • Week 26

    Week 26
    Avary is almost into her third trimester! She is practicing breathing but there is still no air in her lungs (practice makes perfect). She is 14 inches and 1.7 pounds.
  • Week 27

    Week 27
    Avary is now 2/3 the way done! She is almost 2 punds and is 14.5 inches. She now looks much like she will at birth and her brain is still rapidly developing. And her mommy better keep playing the tunes!
  • Week 28

    Week 28
    Avary weighs 2.2 pounds and is 14.8 inches. Her eyes are moving in their sockets and her milk teeth are coming in! Her mom should continue to to speak to her to calm her down and lower her heart rate.
  • Week 29

    Week 29
    Avary weighs 2 and a half pounds and is 15 inches. SHe sure is moving! Her movement is more forceful and her head is growing in order to accomidate for her brain.
  • Week 30

    Week 30
    She's getting big! Avary is 3 pounds and 16 inches. Her umbilical chord used to be her source for nourishment but now it is carried onto the bone marrow. She is also getting fatter and is now controlling her own temperature.
  • Week 31

    Week 31
    Avary's eyes are now open! She is 3.5 pounds and 16.5 inches. Her eyes are now completely open and she can sense light. She also may jumo at loud noises so no horror movies!
  • Week 32

    Week 32
    Avary is 4 pounds and 17 inches. She is straight up snoozing most of the day and the uterus is becomming more cramped. Her mom should make sure to perform a kick count to make sure movement is regualr.
  • Week 33

    Week 33
    Avary is now 4.4 pounds and 17.5 inches. She is drinking about a pint of amniotic fluid a day (yuck)! Her mother will gain about a pound a week until birth and half of that weight is going towards Avary.
  • Week 34

    Week 34
    Avary is now 18 inches and 5.25 pounds. She has an excellent chance of survival now! Her fat is plumping around the arms and is already in formation for liftoff.
  • week 35

    week 35
    Avary is now 18.5 and over 5.5 pounds! SHe's getting so big!!!! She is now getting rounder because of her developing fat. and her lungs are basically fully developed!
  • Week 36

    Week 36
    Avary is now 19 inches and 6 pounds. She is getting pretty dang chubby! Her mother is now feeling contractions and Avary is now prepping more into launch.
  • Week 37

    Week 37
    Avavry now weighs 7 pounds and is 19.5 inches! She is growing up so fast :( water can now be broken at any time.
  • Week 38

    Week 38
    Avary is now 20 inches and weighs about 7.25 pounds. Fat is continuing to build up and the skin is smoothing out. She may now also be in the final position before birth.
  • Week 39

    Week 39
    She is almost here!!!! It is getting so close and she is very restless. She is still about the same size as last week and doesn't seem to be growing anymore. We can't wait to see her!
  • Week 40!!!!!!

    Week 40!!!!!!
    Avary has now reached her delivery date! Contractions can begin at any moment now and Avary is patiently waiting to be squeezed out of her cramped home. This has been such a wild ride.