Your baby from week to week

Fetal development

 Week 1: Maths

At this time you are not pregnant yet. So why does this week count? This is to calculate as accurately as possible when the baby will be born. The time of conception is not calculated from the day of conception, but from the first day of your last period.
By adding nine months plus seven days to this day, you can calculate the due date yourself. It is of course an estimated date. Whether the baby will come on that exact day is still very much the question. Your due date will be estimated after an ultrasound at our practice. 



Week 2: A small chance

At the start of this week, you ovulate. Your egg is fertilized 12 to 24 hours later if a sperm penetrates it – and this simple biological occurrence begins a series of increasingly complicated processes that leads to a new human life, if all goes well. Over the next several days, the fertilized egg will start dividing into multiple cells as it travels down the fallopian tube, enters your uterus, and starts to burrow into the uterine lining.




Week 3: Fertilization

When the sperm has come into contact with the inside of the egg, they merge, like two bubbles become one bubble. This bubble is the first cell of your child, it then divides first by two, then by four, then by eight, and so on. After about a week the egg settles in the uterine wall and is already a lump of sixteen cells. In that virtually invisible lump is already a lot set such as the build of your child, the color of hair and eyes, the intelligence, the character and even the smell of the skin!




Week 4: A small hard working group of cells

The lump is growing so fast, it has now multiplied into several thousand cells and could be visible to the eye. Your baby-to-be is now an embryo. Over the next six weeks, its nervous system, connective tissue, and organs will start to develop. Your embryo consists of two layers of cells called the hypoblast and the epiblast, from which all of your baby's organs will be made. This small group of cells will settle itself in your womb and will be fed by the blood vessels of the uterine wall.




Week 5: A grain of rice

The lump of cells that will soon become your baby is now about the size of a grain of rice. It's even starting to take shape a bit. If you look closely, you could discover a head and a tail. Your child's development is fascinating. Think of all the body parts of which we have two of. Two arms, two eyes, two lungs, two kidneys ... They are formed at the same time, but from different groups of cells. It's hard to believe that one group can take care of the left ear, while another group makes an ear of the same size and shape for the right side! In the meantime, your uterus is being shaped into a safe nest.



Week 6: A beating heart

The lump of cells is now officially called an embryo and looks a bit like a shrimp. Slowly a head and a neck emerge. There are also eyes that are still far apart, almost on the each side of the head. In the center of the face the tip of the nose starts to form. The spine is faintly visible on an ultrasound. There is already a blood circulation and a start has been made with organs such as liver and kidneys and the gastrointestinal system. And, perhaps the best thing to know, the heart has started to beat! You can see the beating heart on an ultrasound made through the vagina.



Week 7: Arms and legs

The baby grows with 1 millimeter a day and is now the size of the nail on your little finger. The development of the arms is going very fast. Last week there were only a few lumps visible, now the baby already clearly has an upper and lower arm. In three days a disc will appear at the end of the forearm in which you can already see the beginning of five fingers. The will appear a little later. Compared to the rest of the body, the head is very large. It will be like this for a long time: the body will only become bigger later in the pregnancy. It will get the right proportions a long time after the baby is born.



Week 8: Vulnerable

The beginning of the full skeleton will appear and the building of the embryo really starts. The heartbeat is about 140 times a minute, the brain starts to function and can send signals to the organs, the stomach is already working and the liver is making blood cells. The baby in your stomach is growing super fast and is developing in so many ways that it is also vulnerable. That is why, in these first weeks, it is so important that you avoid harmful substances such as alcohol, cigarettes, drugs and medication.




Week 9: A little nose

As of this week, we are no longer talking about an embryo, but a foetus. Your child can already move the hands which are the size of a pea and has a beautiful little nose. Only three centimeters long, it has now a real human face, with a mouth and even a tongue. The arms have also grown a bit further and now have hands with fingers. The legs have knees, ankles and toes. The baby can even move! But you cannot feel that yet.



Week 10: The first milestone

Your child is ‘complete’ and will from now on only grow bigger. It does still take months for the organs to develop, in order to function properly later on and make the baby ready for the outside world. For the time being the baby feels very well in your womb. Once the organs are properly formed, nothing much can go wrong and that is a comforting thought. The baby now has an upper and a lower jaw, which already contains twenty small dots that become the baby’s teeth after birth. The first hair grows on top of the head! The baby usually keeps the legs folded and measures about four and a half centimeters. In this week, the baby is usually measured, with an ultrasound, to determine the due date.


Week 11: Girl or boy

Your child is growing very fast now. In one week it will grow a full centimeter and double in weight! This growth will continue for some time at this speed. After the sixteenth week does it slows down. Not that the baby is impressed by this. It will be sucking its thumb quietly and will not be aware that it is going through an important phase. Because in this period the sexual organs are formed! Although it was already decided at the conception we can see now ovaries for a girl and testes for a boy.



Week 12: Yawning 

Not only does the baby suck on his thumb, he can also grab with his hands, grasp the umbilical cord, stretch and occasionally yawn. From now on he begins to act more and more human. The recently developed eyelids, are clear and cover the entire eye. The whites of the eyes, iris and pupil are all in place. They will not open until the seventh month. The milestone of this week: you might be able to hear the heart beat with the Doptone when you visit the midwife!



Week 13: A little bump

The first months you didn’t notice that the baby was growing. Now that the organs have been formed, all the energy will go into getting bigger and bigger. And so does your belly! Your weight gain does not say anything about the health of the baby. So if you gain little weigt that does not have to mean your baby is not growing.
From now on, the midwife will carefully examine your belly during each visit to check the height of the uterus. From this she can monitor the growth of the baby. When in doubt, she can always make an ultrasound.


Week 14: Swimming around

The baby is moving around a lot, although you cannot feel it yet. It kicks its legs, waves its hands (this can sometimes be seen very well on an ultrasound), makes fists and can even make funny faces. It swims around in the amniotic fluid because for now it still has plenty of space. You won't feel those gentle movements until a few weeks from now. The baby can open the mouth and press the lips together. It is still too early for real suction movements, but he can already swallow. Your child even drinks small sips of amniotic fluid. And when it chokes on it, it gets hiccups!


Week 15: Teaspoon

The head is now the size of a marble, the fists are the size of a pea. In total, with eleven centimeters, the baby is about the same length as a teaspoon. Fine hair called lanugo is starting to appear on your baby's head and body. Over the next six weeks or so, this hair growth will thicken. It grows on the forehead, stomach and hands. The hairs stay until approximately week thirty-seven and are probably to keep the waxy substance called vernix, which protects the baby from infection, in place. The kidneys are already working and your baby even does a little pee now and then, which is properly drained by changing the amniotic fluid.



Week 16: Ten little nails

On the fingers and toes are growing ten tiny nails. And on the face, eyebrows and eyelashes appear. The vocal cords are also ready, but without air the baby cannot make a sound with them. Do you want to know whether it is a boy or a girl? From this week on an ultrasound for sex determination is possible at our practice.




Week 17: Light and dark

The baby grows with an average of two centimeters a week and is now the size of a toothbrush. He is able to distinguish light and dark through the eyelids, the amniotic fluid, the uterine and abdominal wall. So if you sit with your bare belly in the sun, the baby will certainly notice! If you hit yourself hard or fell there is no reason to panic. Fortunately, the baby can take a lot because the amniotic fluid provides excellent protection and absorbs the blow. But if you are worried, call your midwife at Ella.


Week 18: pop?

This week, you can feel movement for the first time: a small "pop" in your stomach. It can also be that your patience is tested and you do not feel anything until the 24th week. Between 18 and 22 weeks you can have an ultrasound made at Ella, where we examine if the organs of the baby are properly formed. Did you know that at this time your child is also developing the fingerprints that it will keep for life? 




Week 19: Athletic

The soft hairs from a few weeks ago are now slowly falling out. In its place, slightly coarser hairs appear, especially on the head. At each visit, the midwife will examine your womb to determine the height of your uterus. The uterus should already be stretched so far that the midwife can feel it sitting just below your belly button. Your baby should be almost half its final height by now. And if it is a very athletic type, it now sucks its feet as well as hands! 



Week 20: Butterflies

The baby kicks, swings, and moves around the womb. If you haven't felt it yet, probably it won't be long now. Maybe you have already noticed something, but didn't recognise this feeling as movements of the baby. Are you pregnant with your second child? Then you may have felt the baby much earlier, even from fourteen weeks! But still, you may have to wait a few more weeks before you feel life in your womb. How do you recognise it? What you will feel can best be described as a butterfly in your stomach. It can be mistaken for rumbling intestines. But if you've felt it a few times, you will know for sure: it's the baby!


Week 21: The womb

You are already halfway through your pregnancy. A strange idea… At this point, the uterus will be stretched all the way towards the navel. The baby is now gaining about sixty grams a week. It still has plenty of room to move and that means you will feel it high and then low in your womb or on the side.



Week 22: Sleeping position 

You have probably noticed that the baby becomes active when you lie down quietly and that he sleeps when you are busy. That might not be as strange as it may seem. When you lie down, your child tries to restore his balance and when you are active, your movements will automatically rock him to sleep. But no matter how active the baby is, it sleeps most of the time. Cuddled up in its favourite position, which is different for every baby: With his chin on his chest and raised knees, or with one leg straight, or a hand on his head, after birth he will do the same, this will be the baby’s favourite sleeping position.


Week 23: Breating excercises

The baby has now reached the weight of 500 Grammes and almost all the organs are fully developed. Your baby can do more and more each day. Not only can he grasp something and hear sounds, he is now also able to breathe. He does not breathe air, but amniotic fluid, in and out of the lungs, which is good exercise. This is necessary, because the lungs are the only organs that are not yet mature enough. The baby also trains its muscles by moving around. The umbilical cord is long enough to have room for that. 




Week 24: familiar songs

The ears are almost finished and the baby is hearing sounds. In the first place the rumbling of your intestines and the beating of your heart. But also your (muffled) voice. Nice to know: the songs you now sing regularly will sound familiar to your baby after birth. It will probably calm him down too. As quiet as these familiar sounds can make him, your baby can become restless from loud music, the slamming of a door or loud voices. This is because of your own reaction to those sounds. You can now try to make contact: When you put your hand on your womb your child will sometimes react to it. Bonding with your baby starts in your womb. The baby is getting to know you better and you are getting to know the baby too!

Week 25: busy baby

Your uterus is now reaching above your navel. The gentle movements change into punching, tossing and kicking. The umbilical cord is so soft and flexible that your child cannot become entangled in it. It is not possible to say exactly how often you should feel the baby move. If it's less, it doesn't have to mean anything. If you don't feel the baby for a few hours, he is probably having a rest. You may also have been too busy to pay attention. Or you are already so much used to the little kicks that you don't even notice them anymore. If you feel significant fewer movements, or you are worried, contact Ella.


Week 26: Listen to the heart

Around  this time the eyes open. It is not known whether this means that your child can see more than only the difference between light and dark. There is another milestone: The baby's heartbeat is now so strong that your partner can (probably) hear the heart beating. All you need is an empty toilet roll. Put his/her ear on the roll on one side and gently press the other end to the womb (do not hold the toilet roll with your hand but clamp it between ear and belly). The best place is about four inches below the belly button. Wait a few seconds, if you don’t hear anything, shift the roll a little.


Week 27: Contact

If you put your hand on your belly and stroke it, the baby will come to your hand. A lovely moment of contact! If you want to do this and it doesn't work straight away, try this: Lie down and breathe through your stomach. Place one hand against the side or on top of your womb. You will notice that the baby moves towards your hand and cuddles up against it. You may not feel it right away, but if you focus and do it on a set time for a few days in a row, you will probably succeed. Or try playing with your child by replacing your hand a few centimeters each time. The baby will come to your hand over and over again. For this you have to relax. Take your time, and try to choose the same time every day.


Week 28: viable

If your baby was born now, it would have a good chance of surviving with medical supervision. But  actually the baby is far from ready. He is only a half year old and still  developing every day. The taste buds and digestive tract have been ready for some time and the baby swallows amniotic fluid and can taste it with its tongue.  The baby has tasted the aromas and flavours from your food for the last months and will trust them and consider them safe. So what you eat during pregnancy will be easier for the child to accept as good food later!


Week 29: day and night rythm

The ratio between the baby's head and body is now more or less normal. Your child now has a clear facial expression. The way he frowns or smiles may look exactly like your frown or your partner's smile. The baby also has its own character and style. You will notice this when you start to monitor his movements. You will see that there is regularity in it, your child has its own day and night rhythm. The way it moves is also very recognizable. If it is kicking its legs very hard now, it probably will do so after birth.



Week 30: Practice contractions

Have you experienced any 'Braxton Hicks' contractions yet? If this is your first baby, it's easy to confuse them for the real thing. The clue is that real contractions get gradually stronger and more frequent with time, while these practice contractions are likely to be irregular and stop after a while. Your baby is getting less and less space. It might already be lying with its head down, but it may also be that it is in  breech (bottom down) position. Nothing to worry about: for another six weeks, the baby will have plenty of room to turn and settle the other way around in the womb.



Week 31: Firm but not ready yet

Your child is becoming more firm and looks "ready". Nevertheless, it is very important that it stays in the womb for a while. The baby would not be able to keep itself warm outside the womb because his temperature system is not fulle developed yet. Your baby's resistance is also not big enough, so the risk of infections is high. If your child would be born this week, it must go straight into the incubator.



Week 32: Big or small?

The little nails have now almost reached the tips of the fingers. The kidneys are working, the lungs are almost ready, the baby is "ready to come out". He is gaining weight only a few ounces a week now. The exact size of the child cannot be seen from your belly. A small belly does not necessarily have to contain a small baby. And  a big baby has not to make a big belly. The size of your belly is not only determined by the weight of the baby, but also by the firmness of the muscle tissue, the amount of amniotic fluid, the degree to which you retain water and fat and your posture. Everyone at Ella who wants this will get an ultrasound at 30-32 weeks. Some pregnant women have an indication to make more frequent ultrasounds than one to monitor the growth of the baby (these are then paid for by the insurance).


Week 33: Lanugo

Some babies are now unable to move in the womb. The  fine hair (lanugo) which covers the baby is slowly starting to disappear. The hairs end up in the amniotic fluid together with detached skin cells and pieces of vernix. The baby drinks from it but this is no problem. If his stomach is too full of the amniotic fluid, the stomach contents can stimulate the diaphragm in such a way that the baby gets hiccups which are actually good for the development of the stomach and intestines.



Week 34: Ligament pain

When you look closely at your belly, you sometimes see a hand or foot "sticking out". Still, the big movements are now over. There is a good chance that your child has turned his head down. You may feel it, because he presses with one leg against your ribs and with the head against your pelvic floor. Sometimes this can cause (severe) ligament pain. You can relieve this pain by sitting or lying down for a while. The bones of your baby are already quite solid at this time, the skull however remains soft enough to be able to pass through the birth canal.


Week 35: The highest point

Around this time your womb (uterus) has grown to many times its original size, and is now up under your ribs. If you would have the baby now, you will have to give birth in the hospital because the lungs can still not work entirely on their own. And so your child would have to lie in the incubator for a while. If it is not clear for the midwife or gynecologist in which position the baby is lying now, an ultrasound will be made this or next week.



Week 36: Deeper in the pelvis

If this is your first pregnancy, around this time the baby will sink its head deeper into the pelvis. With a second child, this usually happens later, because the abdominal muscles are more stretched and so the baby has room. The baby's skin is still covered with vernix, which protects him from infection. Mostof the vernix will come off in flakes around week 35. The flakes then float around in the amniotic fluid. The amniotic fluid shows whether the baby is born at the right time. If the amniotic fluid is crystal clear without flakes, the baby is too early. Clear water with flakes means on time and milky white amniotic fluid means that the flakes have completely dissolved and the baby is late.



Week 37: Raised legs

Don't be alarmed if you suddenly feel your child move differently. The movements are usually now a bit softer and more subtle. This is because the baby has less room and lies with the legs pulled up in the uterus. Sometimes you still get a kick from the feet or a stump from an elbow. If you are concerned about the moves or no moves, always call the midwife. Since the baby is now lying low in the womb and pressing on your bladder, you will probably need to go to the bathroom more often. But maybe you can now breathe easier. It's all about watching and waiting now, as your baby may make his arrival any day but it could very well be a few more weeks.


Week 38: building up

The baby gains twenty to thirty grams of fat per day. This way he builds up a reserve for the first days after birth. This way your baby can get used to the breast or the bottle without getting too hungry or losing too much weight. The layer of fat under the skin is now so thick that the baby will soon be able to keep its own body warm. About ten liters of blood per minute now flows through the placenta, full of nutrients for your baby. If the baby comes this week, you can simply give birth at home.



Week 39: Ready to go

If the abdominal wall is not too thick, your partner can now just put his or her ear on your stomach and hear the heart beat. The baby is lying "ready to go" in front of the cervix. The bones are still flexible that they can easily adjust to the shape of the birth canal: thanks to the fontanelles, the opening between the skull bones, the head can become slightly narrower during childbirth and therefore come out more easily. The skull bones slide over each other during childbirth, making the head look extra oval when the baby comes out.



Week 40: Due!

Finally: the due date, although most babies don't care much about it. The come when they are ready. Do you wonder if the baby will notice much of the delivery? During the first hours he can still get some sleep. When the contractions follow each other up faster, he can move less and he wakes up. The push contractions are the most unpleasant for your child. The head is pushed back and forth. Once the baby is born, all that pressure is gone. Now the baby has to get used in a short time to a new environment, with bright light and loud noises.



Week 41: Miscalculation?

It could be that you start this week without anything happening. Only four percent of all babies arrive exactly on time. It is not exactly known why a pregnancy will last longer. It is believed to be related to the size of the placenta. A large placenta produces a lot of progesterone, a hormone that slows down contraction activity. It may also be that the stimuli to initiate contractions are not strong enough. But rest assured: 90 percent of the babies that are overdue, are born within ten days of the due date.



Week 42: The baby will come!

Being pregnant for more than 40 weeks means that the baby is very happy in your tummy. So there is no reason to worry: it will come! And if the placenta has worked fine for forty-two weeks, the baby will look just like a baby born on time. He will not have vernix on his skin and probably the hands and feet are a bit dried out. When there is something wrong with the baby or if you have been diagnosed with a medical problem, it happens that labour has to be induced.
For all births there is one consolation: you will forget that long wait when you hold your baby in your arms!