12 First Things That The Unborn Baby Develops (10 Things That Develop Last)

When one stops and thinks about pregnancy, it really is a miracle. That a woman can create this little being out of just a bunch of cells. Mankind now knows more than ever thought possible about pregnancy thanks to all the advancements in medical technology. Thanks to the introductions of ultrasounds and other testing, people have been able to take a better look at how babies grow.

Babies in the womb have a specific order in which they develop, and they all follow the same schedule. From their brain, down to their little tiny toes, everything develops while they are in the womb. What is always interesting to know is what order these developments are made. As a woman goes through her pregnancy, she becomes obsessed with learning about her new baby and checking all the websites every week to see what their baby has grown. There are certain things that develop first and then there are things that are the very last to develop.

We are going to go through the growth and development of a fetus and see what will show up first and what waits until the very end. Either way, it all ends up in pure perfection in the form of a little baby.

22 First: Neural Tube

A lot of the most important developments happen in the very beginning, or the first trimester. It is when everything is just starting and why this is the time where the risk of miscarriage is the highest because it is the time when a lot could go wrong. After a woman has been pregnant for about four weeks, the neural tube will start to close along the baby’s back.

This is when a lot of women would just be finding out they are pregnant, so it is amazing to think that so much is already happening with the little baby. The neural tube is very important as the baby’s spine and brain will develop out of this base.

21 First: Brain

Thanks to ultrasounds, we get some pretty amazing pictures like this one that let us know what our little one looks like. As we said in the previous section, the neural tube is the basis for the brain and spine to develop. The brain is one of the most important organs, and it is one of the most complex.

Due to it being so complex, it needs a lot of time to develop and grow so it makes sense that it would develop first to give it the time it needs. The brain continues to grow and develop well into toddlerhood, so its work is not done when the baby is born.

20 First: Spinal Cord

At the same time the brain is developing, so is the spine. Thanks again to the neural tube. Unfortunately, neural tube defects are one of the biggest contributing factors to miscarriage and birth defects, so mom is always relieved when she hears that these are developing fine. The spine is not a body part we all focus on, but it would be pretty hard to survive without out.

This is one of the first things to develop and it will grow right alongside the brain and other organs. It will support the baby and it will be closely monitored by your doctor as your pregnancy progresses. It is also one of the most noticeable things to see in an ultrasound picture.

19 First: Heart

How do we define life? We define it by love and relationships which are all formed by the heart. OK, maybe not exactly but the heart is the most important thing in our whole body. It is the essence of who we are, and if it does not work than neither do we. Such an important organ is one of the first things to develop and it brings a lot of joy to mom’s own heart.

The heart starts beating very early in the pregnancy and if mom went for an ultrasound at 6 or 7 weeks pregnant, she would see the little tiny heart beating away. This goes a long way to calm a nervous mom as once a heartbeat is detected, the risk of miscarriage drops drastically.

18 First: Eyes And Ears (Almost)

It really is amazing when we think about the fact that most of the growth and development happens before we even know we are pregnant. By the time a woman is 4-weeks pregnant, which is only 2-weeks past conception, so much has already gone on. Without mom even noticing her little baby already has the base for their little face.

Structures for the eyes and ears are already in place. Structures that they will need to fully develop a little bit later. If these did not develop, they would not be able to grow into those cute little blue eyes, or brown or green.

17 First: Face

A woman spends 9-months dreaming about what their little baby’s face will look like. Science is getting close at giving us a sneak peak. Ultrasounds further along in pregnancy can give us a pretty good idea, and now there are 3D ultrasounds which give us an even better look. However, the face start to develop much earlier in pregnancy, around the 7th week.

It won’t look anything like this ultrasound photograph which was done much further into a pregnancy, but it is starting. The face is growing and all the shapes and depressions it needs are already in place and defining more and more every day.

16 First: Nostrils

A lot of the early development in the fetus is fine details. They are taking their time to grow and develop slowly to make sure they are perfect for when the baby is born. Along with the face that is quickly growing is the baby’s nostrils. That’s right, that cute little button nose you can’t wait to stare at is already forming.

It will take a while for the actual nose to appear, but the holes that are meant for the nostrils will already be formed. This is partly why the look of a fetus at this stage of pregnancy can be a little off-putting, they don’t look like the cute cherubs we expect when they come out fully cooked.

15 First: Little Buds

It may still be a little while before you feel the little arms and legs kicking and punching away in there but that doesn’t mean that they are not already hard at work growing. Early in the first trimester, little buds that will form the arms and legs will start to form and sprout out of the baby’s torso.

These cute little limbs will still take some time to form to the shape we know and love, but the groundwork is already there. Before mom knows it, the baby will be punching and kicking away, and she will want them to go back to the little bud shape.

14 First: Fingers

Along with those little arm buds comes fingers. The fingers develop pretty early in the pregnancy though they do not look like what we would expect them too. When the hand and fingers are first formed, they look more like paddles. They are webbed like a duck and they take some time to separate into fingers.

It is almost like a rite of passage when a baby is born that mom and dad need to make sure that their baby has ten little fingers and ten little toes. It is almost like a universal sign that the baby is happy and healthy. That, or they are just too cute not to look at.

13 First: Lips

One of the cutest features on a little baby is their little lips. Mom and dad can’t wait to pucker up and give their baby all of the kisses that they can manage. Lips are another thing that is developed fairly early in the pregnancy. When the head and face form, so do those little lips of theirs. This is a feature that a lot of people love to see when they get a 3D ultrasound done.

Whose lips will the baby have? Moms or dads? It is always fun to try and figure out who the baby looks like, though they continue to change so much it is often hard to tell.

12 First: Toes

Is there anything cuter than little, tiny baby toes? There is some unexplainable reason why mom and dad, and anyone else who looks at your baby, wants to nibble on those toes. They just call to people. The toes will also form fairly early on in the pregnancy. As soon as those little leg buds sprout a little bit, there will be 10 perfect little toes growing next.

Baby feet are so tiny, and their toes are even smaller. It amazes a lot of women, and people, that by the end of the first trimester they have a very small miniature person in their belly. Development really does happen that quickly.

11 First: Elbows

By the time a woman is 10 weeks pregnant, she is almost done her first trimester and her baby is growing rapidly. The accomplishments it has done are nothing short of amazing. When she hits that 10-week mark, the baby’s head is starting to look more round in shape. This baby also has elbows now and is starting to get some good practice in.

The baby has started to move their elbow and will continue to do so as a way of practicing for the outside world and strengthening the muscle needed. Before long, you may feel a sharp elbow hit in the ribs.

10 Last: All Five Senses

We have now moved on to the things that develop last in a baby. A lot of the work has already been done by the time a woman has reached her third trimester, and her baby is now focusing on fine tuning a lot of things and getting bigger in size. One of the last things that will develop are the five senses.

Babies have the equipment needed to see, smell, hear, taste and touch but they need time to develop these organs so that they can use them. They will start tasting the amniotic fluid and they will soon be able to hear the outside world.

9 Last: Eyelashes

Have you ever looked at some babies and thought that they have eyelashes that a lot of people would pay good money for? Some babies are just gifted when it comes to long and luscious eyelashes. My daughter is one of those children and I am so envious as she got them from her father and not me.

Eyelashes develop at the end of the third trimester. They simply do not need them in the womb. The purpose of eyelashes is to keep dirt and other particles out of our eyes. They are in a sterile location, so they do not need this protection just yet.

8 Last: Hair

Hair is a tricky thing because not all babies are born with hair. Some are born bald, some are born with some peach fuzz and some are born with a full head of hair that already needs a good shampoo. Hair is a genetic trait, but for babies that are born with hair, it is one of the last things to develop. It also can be visible on ultrasounds.

Hair is not something that is necessary for happy and healthy life, so it makes sense that the body would focus on growing and developing other areas first before turning to the beautiful head of hair.

7 Last: Lungs

It seemed pretty apparent that all the major organs have developed in the first trimester, but there is one that takes a little longer to develop and that is the lungs. The lungs are the last major organ to develop and this can pose a problem. This is why it is so dangerous when a baby is born premature, as the doctors are not sure how their lungs are working, if at all. A lot of them need the assistance of oxygen when born.

Women who are at risk of delivering early may also be given a steroid shot to help the lungs develop quickly. This is the biggest reason why it is so important to make sure that baby can cook for as long as possible in the womb.

6 Last: Nails

When we are pregnant, our mind and worries are on all the body parts that seem most important. We worry about the heart, brain and even the kidneys. We often forget to marvel at the small, fine details that are also growing. Fingernails and toenails are also one of the last things to finish developing.

I say ‘finish developing’ because they have been there for as long as your baby has had fingers and toes, but they were not quite done yet. Near the end of the third trimester, the nails will start to harden up. They have been in a liquid state for almost 40-weeks, so they have been soft and pliable. This is also to help prevent them from tearing the sac or scratching themselves while they are in the womb.

5 Last: Fingerprints

Another fine detail that will take some time to develop are fingerprints. That’s right, have you ever taken a really good look at your baby’s hands? If you looked closely at the underside, you would see that the baby has their own set of fingerprints. Everyone’s fingerprints are unique, so this is something that is there’s and there’s alone.

Things like fingerprints are often overlooked because parents are too busy making sure their baby has all of their limbs and that their heart is beating away. It is always a good idea to really spend some time looking at your baby and marveling at how this whole creation thing works.

4 Last: Cheeks

The reason babies look like little cute cherubs is because they have those chubby little cheeks. Those cheeks that their great aunt will love to pinch when she comes to visit. By the time mom is in her 6th month of pregnancy, her baby will look like an actual baby in every way, except the face.

The eyes will still be the most prominent feature on the face and that is because the fat deposits in the cheeks have not been developed yet. This happens later on in the pregnancy, and the reason that babies have chubby little cheeks is to help them suck from a breast or bottle. It prevents their cheeks from sinking in.

3 Last: extra warmth

One of the last things to develop on a baby is their chubby little body. It takes a while for them to build up fat in their body. This is one of the very last things a baby does. Other than the lungs, this is what the fetus will spend the remainder of the pregnancy doing, plumping up. It is one of the quickest growths spurts they will ever experience.

It is important that baby’s put on the pounds and ounces while they are in the womb because they are going to need it when they leave. It will help them regulate their temperature when they are met with the outside world. If a doctor is concerned about the baby growing, they may do growth scans near the end to make sure the baby is putting on the weight.

2 Last: Private Areas

This one is a little tricky, because it can be misleading. The baby’s gender has already been earmarked since the moment of conception. By the end of the first trimester, the genitals are forming, and it won’t be long until mom and dad can find out what their little bean is by ultrasound. This area will continue to develop as the pregnancy progresses, and especially if you are having a little boy.

If you are carrying a boy, it isn’t until the 8th month of pregnancy that their little testicles start their descent to meet the rest of their body. They will come out looking absolutely perfect though.

1 Last: The First Diaper-full

Babies eat in the womb. Well, they don’t eat as we would eat but they are practicing. They are taking in amniotic fluid and their body is working to process it through their little body. This practice helps get them ready for the outside world and for feeding. However, just as it will when they are born, this material gets turned into waste.

A baby does urinate in the womb, but they do not have a bowel movement which is a very good thing as we do not want them ingesting it. The first bowel movement is developing in their little body and it won’t be long once they are born that mom and dad will face their first very messy diaper.

References: Mayo Clinic, Family Doctor, MYDR

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