Pregnancy week 21
8 Jan. 2026
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Pregnant in week 21? In this article, you can read all about your baby’s development, changes in your body, and get useful tips for this stage of your journey.
During the first half of pregnancy, all foetuses grow at a relatively even rate. From week 21, however, they start to grow at a more individual rate, and you can see greater differences in different measurements.
The size of the foetus is affected by genes, the size of the placenta that transports and filters nutrition, the flow of nutrition in the vessels of the umbilical cord, and last but not least, the growth of each individual is unique. Development and size can also differ depending on whether you are at the beginning of, or at the end of, a week of pregnancy. A lot can happen in seven days!
The senses continue to develop and the baby is still active in the abdomen and moves around a lot. The movements become increasingly advanced and the baby can now do forward and backward somersaults!
The sweat glands are already fully developed, but even though the foetus moves a lot, it will not start sweating until after birth. In addition to eyelids, the baby now has eyelashes and their eyes can react to light. However, the baby has not started to open their eyes yet. Around week 25, we know that many babies can open and close their eyelids in the womb.
Around week 20, the skin is covered with a thin layer of vernix mixed with dead skin cells, as well as hair that protects the sensitive skin from the amniotic fluid.
The amniotic fluid volume is now around 400 ml. When the foetus is in the womb, it does not need to use its lungs to oxygenate the blood, instead it trains its lungs through the chest muscles, which practice making breathing movements. The baby drinks amniotic fluid and then the liquid is absorbed by the gastrointestinal tract. The kidneys then produce urine, which the baby urinates out. In this way, the amount of amniotic fluid is affected by the foetus itself! Even the placenta and amniotic membranes are involved in the process of forming amniotic fluid. However, the amniotic membranes are most involved during the first 15 weeks of pregnancy.
The uterus continues to grow and now reaches a few centimeters below or around the navel. In some women, the navel may begin to protrude around this time, but it may take some time, just as the size of the abdomen varies. If it is not really visible yet, that will certainly start to change in the next few weeks because the foetus is going through a major period of growth.
How visible the pregnancy on the outside is affected by several different factors. Among other things, whether your uterus tips forward or is more backwards, how long or short your torso is and how strong your core muscles are. There can therefore be a big difference in how visible the stomach is depending on how your body is built! So, it is good to remember not to compare your pregnancy to others during your pregnancy journey.
During pregnancy, the blood volume in your body increases and you may need to replenish your iron reserves with the help of dietary supplements. Iron is a substance that produces haemoglobin in the red blood cells, which in turn transports oxygen around in the blood. This makes iron especially important for both you and your baby! Your midwife will monitor your blood count (haemoglobin) on several occasions during pregnancy.
If you need to get more iron, your midwife will let you know. As the foetus cannot produce its own iron and instead consumes your reserves and whatever you replenish them with, it is common for people to take iron supplements during pregnancy. Even if you have a good baseline iron level, you may need to use supplements.
You can also eat an iron-rich diet including meat, poultry, fish and eggs. If you are a vegetarian, you can get iron from; whole grains, nuts, seeds, dried fruit, spinach, green leafy vegetables and legumes.
Feel free to combine an iron-rich diet with vitamin C as it improves iron absorption, while certain foods, such as caffeine, can inhibit it. Vitamin C is found in the majority of colourful fruits and vegetables such as; kiwi, orange, strawberries, peppers, broccoli and kale.
If you have not already received a maternity certificate, you will receive it from the midwife around this time. You need to give this to your employer or post it to the address on the back of the Mat B1 – Read more here!
The Mat B1 certificate is the first step to being able to plan parental leave. When you send in the maternity certificate to your employers, they receive information about the pregnancy and can set aside parental days according to the parental leave of your company, so that you and or your partner can plan how you want to take the leave. If the prevailing rules feel complicated, there is a lot of help and information available via their website. If you think it’s nice to listen instead of reading yourself, there are also various Webinars.
Around week 20, many pregnant women feel irregular foetal movements, but it can take longer if, for example: your placenta is in the anterior wall, it works as a cushioning cushion.
How the foetal movements are felt during this and the coming weeks is very individual and it is not unusual that it is only later that you understand that it was the baby’s movements that you felt. The feeling can sometimes be likened to a sweep or vibration that could just as easily be air in the intestines. However, there is a high probability that it is movements from the baby that you feel, and if so, it will become clearer in the next few weeks.
Why not do something fun together and celebrate reaching the halfway point!
Half of the pregnancy has now passed and in all likelihood the second half will go faster than you can imagine. If now seems like the right time, you might want to start thinking about what your baby will need once they have been born! The most important things are of course love, food and care – but there are also things that can make everyday life with a baby easier.
Under “Tools” in the app, you will find checklists for the arrival of your baby that may be useful to look through. Apart from avoiding feeling stressed close to the birth, you have time to plan purchases well in advance and also spread out the costs.
The pregnant woman will receive a maternity certificate, (Mat B1) from the midwife, which you give to your employer or send to the address on the back of the form. See here.
Your paternity leave will be registered in the name of the pregnant woman until your baby is born, but it is up to you to decide how you want to use the days. Many families appreciate having continuous free time together when the baby is newborn, both for the sake of the family but also to be able to support each other as new parents. As a partner, you are entitled to paternity leave in connection with the birth of your child and then can be at home to get to know the new family member.
