18th week of pregnancy – baby’s development, changes in the body, tests and indications

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You enter the 18th week of pregnancy. Many women get nervous at this time because another checkpoint is coming – a half ultrasound – and you will soon find out if the fetus is developing properly. See how your baby and your body are changing during this time.

18th week of pregnancy – the most important information

Now, in the 18th week of pregnancy, your baby can be up to 15 cm! At the same time, it can reach a weight of 200 g, i.e. two bars of chocolate. Below you will find a table with the biometric dimensions of the fetus:

However, do not worry if the ultrasound shows that your baby is slightly smaller. From around the 10th week of pregnancy, babies develop at a different rate depending on, among other things, your lifestyle and diet, but also genetic factors. First of all, remember to eat healthy and categorically not drink alcohol or smoke cigarettes. Addictions can contribute to serious impairments in a child’s development, but also to low birth weight.

If you can feel your baby’s movements clearly, although many women do not see this moment until 22 weeks pregnant, you may find that your baby alternates between moments of increased activity and calmness. Like every human being, your little one needs sleep too and when he is not moving, he just rests.

With careful observation already in the 18th week of pregnancy, you may notice something interesting. The baby usually moves when you are resting, and when you start to move, the baby stops. Perhaps this is when he gets used to the fact that rocking calms them down. After giving birth, you will probably find that nothing puts your baby to sleep as effectively as carrying it in your arms. Fortunately, your partner will be able to help you out at this stage.

Do you want to know which week of pregnancy you are in? Check: How many weeks does pregnancy last? Pregnancy calculator

18rd week of pregnancy – baby’s development

Since the baby is asleep from time to time, he also… yawns! Sometimes, an ultrasound scan in the 18th week of pregnancy captures this endearing moment. Parents are then most often surprised that their toddler already performs such characteristic reflexes.

During organogenesis, all organs developed and now the process of their maturation continues. Most of them have already taken up their functions, but there are also some that will not be ready for some time. One of the organs that takes the longest to develop is the lungs. Although the baby has been making breathing movements for some time to develop the muscles necessary for this process, alveoli do not form until the 18th week of pregnancy. The process of perfecting these delicate structures will take weeks to come.

The child’s nervous system also specializes. The brain is already connected to the muscles by nerves, but at this stage they are very primitive. The axons of neurons, i.e. their long projections, are still devoid of the myelin sheath. This shell is formed just in the 18th week of pregnancy. Thanks to it, the impulses will travel through the nerves faster. This will come in handy when your baby starts crawling and curiously stuffing his hands everywhere. A pain stimulus, such as a warm oven, will be immediately transferred to the brain, so that the child will quickly withdraw his hand and not burn so badly.

At the stage of the 18th week of pregnancy, a characteristic substance begins to form, which the baby is covered with after delivery, i.e. the embryo. The goo is not the most beautiful sight, but think what a newborn would look like if it were not there – it would be wrinkled like the fingertips of someone who has been in the water for too long. The goo is made up of, among others, dead cells and secretions of the sebaceous glands. In addition to isolating your baby from a fluid environment, it also has other tasks. Vernix slime mechanically protects the fetus from getting cold. It is also an additional barrier to pathogens and maintains proper acidification of the skin.

In addition, the baby’s hands and feet are already formed, and the fingerprint pattern can be seen on the surface of the fingers. During the examination, the child’s facial expressions can also be noticed.

In the 18th week of pregnancy, the baby’s heart is already divided into two chambers, and its shape is so advanced that the doctor, during an ultrasound examination, can find out any birth defects. Thanks to the possible diagnosis, prenatal cardiological procedures can be performed.

In the 18th week of pregnancy, the previously formed digestive system also develops. During this period, the pancreas and the liver begin to function. In turn, the intestines fill with meconium, i.e. the baby’s first poop. This means that the intestines gradually start working.

How does the fetus develop in the trimesters of pregnancy? Read: Fetal development stages – XNUMXst, XNUMXnd and XNUMXrd trimesters of pregnancy

18st week of pregnancy – changes in your body

You are getting more and more rounded. In some women, the abdomen stands out strongly and clearly from the entire figure, while in others the entire abdomen gently slides forward. At 18 weeks of pregnancy, your weight should be 3,5-5 kg ​​more than your pre-pregnancy weight.

By the 18th week of pregnancy, your uterus is already the size of a small melon. No wonder she teases you more and more. The ligaments it is suspended from are constantly stretched and their soreness is completely normal. If this is your first pregnancy, it should be comforting to know that the ligaments won’t hurt that much with your second baby.

But not only with these ligaments something unusual is happening. In the pregnant woman’s body, relaxin is slowly released – a hormone responsible for loosening other ligaments, which will make childbirth a little easier. Pain in the joints is a side effect. You may also notice that your foot is … slightly bigger.

In addition to relaxin, it may also be affected by the fact that swellings appear in the 18th week of pregnancy. For obvious reasons, they mainly affect the lower limbs, from which the blood has a difficult outflow, because it must move against gravity. Non-forcing walks and rest with your legs slightly elevated above your heart will help you in this. Always remember that when you lie on your side, you should choose the left side, which will minimize the pressure on large vessels.

Now, in your 18th week of pregnancy, you may experience calf cramps more than ever. Scientists are not able to fully explain this phenomenon, but it is postulated, among other things, that the legs are simply not used to the additional load. In addition, your entire body undergoes enormous effort and its economy changes slightly, which can also upset the proper functioning of the muscles.

If it’s summer, you probably want to bask in the sun. Traveling in the 18th week of pregnancy is not prohibited, but you should definitely watch out for the sun. During pregnancy, the skin is more sensitive than usual and new birthmarks are formed on it. Some of them will go away after giving birth, but if you get discoloration now, they may stay on your skin for good.

Learn about ways to treat stretch marks in pregnancy: Stretch marks in pregnancy – can you get rid of them?

18th week of pregnancy – what is worth paying attention to?

During the 18th week of pregnancy, the mother’s body undergoes various changes that are not always pleasant and cause discomfort. What is worth paying attention to at this time is primarily:

1. back pain – it is caused by the constantly enlarging abdomen shifting the center of gravity up and forward. As a result, back pain becomes more intense and occurs more often. In addition, hormonal changes that accompany pregnancy relax the joints, which makes the muscles that are additionally strained much faster. To prevent back pain, you should rest more and spend a lot of time lying down;
2. heartburn – is the result of the pressure of the enlarging and rising uterus on the stomach. This pressure can cause heartburn and frequent belching. In addition, progesterone, which is produced more intensively during this period, relaxes the esophageal sphincter. In the 18th week of pregnancy, a woman provides her body with more calories, which means more meals. This can also contribute to the onset of heartburn. Of course, it can be prevented by eliminating fatty, spicy and hard-to-digest foods from the diet;
3. increased amount of vaginal discharge – in the 18th week of pregnancy, there may be vaginal discharge of various colors. This should not be a cause for concern. However, if the discharge has an unpleasant odor, consult your doctor. During this time, you should especially take care of proper hygiene of intimate parts and body. 

What are the symptoms of pregnancy? Check it out: Pregnancy symptoms – fertilization, how to recognize them and when do they appear?

How to take care of yourself in the 18th week of pregnancy?

The period of pregnancy is a special time for every woman. You should take care not only of your baby’s health, but also of yourself. In order for the pregnancy to run smoothly and the baby to develop healthy, there are a few basic things you should take care of in the 18th week:

1. diet and weight control – in the 18th week of pregnancy, the need for nutrients increases. During this time, it is worth going to a dietitian and using his advice or asking for a menu. It is worth expanding your diet with products rich in iron, B vitamins, especially folic acid, zinc and calcium. In the 18th week of pregnancy, weight gain should not exceed a few kilograms;
2. physical activity during pregnancy – many women say that exercise should not be exercised during pregnancy as it can harm both the mother and the baby. Nothing could be more wrong. Properly selected exercises will help to strengthen the spine and make it easier for the future mother to give birth. Light gymnastics counteracts back pain. It is also worth going to the swimming pool, doing yoga or pilates;
3. preventive measures against edema – in the 18th week of pregnancy, swelling of the ankles and feet is common. Water accumulates in the woman’s body, which is necessary to regulate the metabolic changes taking place in it. Therefore, future mothers should spend a lot of time resting and slightly lift their legs up. It helps to improve the flow of fluids in the body and prevents excessive accumulation of water in the tissues. 

Check what exercises you can do during pregnancy: Exercise during pregnancy

Especially important in the 18st week of pregnancy

In the 18th week of pregnancy, you can consider choosing a birth school. It is true that most of them accept classes only after the 22nd week of pregnancy, but not all of them have enough vacancies, so it is worth choosing at least three facilities in which you are potentially interested.

Do you want to know more about birth schools? Check: Why is it worth going to childbirth school?

Tests in the 18st week of pregnancy

Between 18 and 22 weeks of pregnancy, you should have a second genetic ultrasound to monitor your baby’s development. Even if you do not plan to have your test at this point in time, make an appointment to make sure it will be on time.

During the half-time ultrasound, the structure of the fetus is assessed in detail by examining individual organs. In addition, it is checked how the placenta is located, how much water there is in the uterus, and what the cervix looks like.

How to plan the 18th week of pregnancy?

In the 18th week of pregnancy, there are some important things to keep in mind for your health. In the pregnancy calendar, it is worth making the following notes:

1. folic acid supplementation at a dose of 0,4 mg;
2. DHA supplementation at a dose of 500 mg;
3. vitamin D3 supplementation as indicated by the doctor;
4. care for the spine – it is worth going to the swimming pool or massage;
5. signing up for a half ultrasound.

An interesting fact about the 18nd week of pregnancy

Is the fact that the baby yawns surprising? It’s still nothing. In the 18th week of pregnancy, she may even have… hiccups!

Find out more about the next weeks of pregnancy. Check:

19th week of pregnancy

20th week of pregnancy

21st week of pregnancy

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