Pregnancy trimesters; what happens when? | Mom & co

Pregnancy trimesters

Dividing a pregnancy into terms is actually a bit crazy, because every pregnancy is unique. But if we do try to explain a pregnancy, you can say that it lasts about 40 weeks, and that it can be divided into 3 different stages of pregnancy. Every trimester of pregnancy is different and brings new challenges and changes. What we know is that few women give birth on their due date and every pregnant woman has different ‘illnesses’. And to make it even more complicated; these are experienced differently by every pregnant woman.

The first trimester of your pregnancy (1 to 12 weeks)

The first trimester is often an exciting trimester and, until the first ultrasound, quite an uncertain one. 80% of all miscarriages occur in the first trimester. Please note: as soon as you have had an ultrasound where you have seen and heard the heart beat, the chance of a miscarriage is only 2%.


The nice thing about this first term of pregnancy is that you are often already in it without noticing it. Because in this trimester fertilization and implantation take place, which you sometimes don’t notice. After conception, the hormonal changes start in the mother, and you experience the first pregnancy ailments. Your body will produce the hormones HCG, progesterone and estrogen. As a result, you will sometimes experience fatigue and/or nausea. You may get sore breasts or gain weight. This is also where mood swings come into the story – you may remember them from your period. Oh yes, one minute you want to eat a lot, and then nothing at all. You will urinate frequently and may experience constipation.

No ailments to get excited about. But there is good news; they usually disappear in the second trimester.


What happens to your baby in this trimester? A lot! When the fertilized egg has implanted, your baby grows to a size of 6.5 cm. Organs such as the brain, heart and circulatory system are built. The heart is the first organ to function, and it starts beating from the 21st day. From about 6 weeks you can see a beating heart on the ultrasound. Also in this trimester the sex is formed. At week 8 the placenta is formed; an incredibly interesting organ that, in addition to producing nutrients and oxygen, produces all kinds of hormones for the growth and development of your baby.

The second trimester of your pregnancy (weeks 13 to 26)

Many women find the second trimester the best of the three. Most pregnancy ailments are gone – or you’re used to them – you’re a little more confident because of the ultrasounds you’ve had and you’ve shared news with friends and family. What else will happen during this special period?


You may feel some growing pains in your abdomen, also known as ligament pain. Logical, because your baby, uterus and belly are growing. You will also get a visible belly. During this trimester you will gain about half a kilo per week and you may become more forgetful. The latter is called pregnancy dementia, a term you have probably heard. Ideal to use if you have forgotten to do your shopping. You will also choose a pregnancy course during this trimester.


In the second trimester of pregnancy, the baby will grow significantly. Your baby grows from 6.5 to 37 cm, and from 325 grams to about 940 grams. Around the twentieth week you will have an extensive medical ultrasound where the sonographer will check whether your baby has any physical abnormalities. A baby is viable from 24 weeks, so milestones are set. What’s sometimes a little crazy about this trimester is that you usually feel really good and you may not always feel like you’re pregnant. If around 18-24 weeks the movements of your baby can be felt more and more clearly, the pregnancy will become more ‘real’.

The third trimester of your pregnancy (27 weeks – delivery)

The third trimester of your pregnancy is the hardest for most women physically, but mentally calmer. Your belly gets bigger and can sometimes get in the way for a while. Your baby’s steps are sometimes visible, and if everything goes well, your baby will continue to grow.


Stopping working and surrendering to the urge to nest is very nice, but at the same time there can be some tensions towards the delivery. It’s really getting close now. With this trimester come some new ailments. It is quite common that you suffer from your lower back and pelvis. The cartilage in your pelvis softens so that it is more mobile during childbirth. Very well thought of by mother nature, but sometimes certainly not nice. If you have problems with your pelvis, please contact a pelvic physiotherapist. In the Mom & co podcast (ep. 5) we recorded a very nice episode with Jody Kienhuis, a pelvic physiotherapist who gives valuable tips on this subject.


Your baby grows from 940 grams to an average of 3400 grams and is about 50 cm long. In this trimester you can make more and more contact with your baby and that is very special. Not only will you feel the baby move more and more, but he or she will also respond more and more to sounds and familiar voices. The eyes open, they start to swallow, hiccup and sometimes suck their thumb. The brain develops quickly, the internal organs have finished developing at the end of this period and a lot of cartilage is converted into bone. In the third trimester of pregnancy, you will talk to your midwife about the birth. It is useful to have a birth plan made before you have this conversation. Then waiting for the first signs of labor is the most important thing for you to do.

A beautiful loving message from us is that, despite perhaps the discomfort, ailments and tension that sometimes color your days: the third trimester of pregnancy ends with one of the most beautiful encounters that you and your partner will experience: the meeting with your baby.

Blog: Een eerlijk pleidooi van een jonge moeder over haar zwangerschap

An honest plea from a young mother about her pregnancy | Mom & co

You have invented something new: you climb on me, and you half standing drink from my breast. I feel my heartbeat echoing in your stomach and I go back to the first time I heard your heartbeat.

The first ultrasound of my pregnancy. You were nine weeks and you were already asserting yourself, our baby. Your father and I hadn’t been together very long, but I knew then that you would come. After a summer full of holidays and festivals you started to exist. Was it Berlin, on the French coast or somewhere on a Wadden Island? What I did know is that you are made of love, my little girl. You came from so much love and happiness, and I felt it too, but I also encountered another side. A dark side that hurt, that sometimes brought fear and uncertainty and made me nauseous.

I was so tense for a while, and I felt really bad sometimes. It was difficult at times, while I thought: I must be very happy, right?

But you don’t hear about this from friends. Sometimes it seems like you are expected to be pregnant all the time. It is, but it is also a huge challenge for body and mind. I therefore advocate that we be more honest, and that we talk more about it. Much more!

A large proportion of pregnant women, especially in the early stages of pregnancy, are extremely nauseous. If you are unlucky you also vomit every day and that can make you feel really bad. You should be happy, but it seems like your happiness can’t connect with your body for a while. You become exhausted, and without energy it is very difficult to enjoy a new life ahead.

Try not to ask too much of yourself in those moments. A new life is growing inside you, at an insane speed. This takes so much energy! Therefore be gentle with yourself and do not demand that you still have to be able to do everything. Accept grumpiness, be lifeless. Drink extra water or tea, eat small amounts. And take naps, OMG take naps! Put some crackers on your nightstand so you can eat them before you get up. And know this: Your pregnancy lasts nine months, that nausea is getting less, really. When you start to feel better physically, there will automatically be more room for happiness. Practice this mantra that you can use in a young motherhood as a new mom: Everything is a phase, everything is a phase, everything is a phase.

It is also important that you keep talking. With your partner, your mother, a friend, or maybe someone who is a little further away from you. You are not alone. There are also great groups to be found online. And we, at Mom & co also try to create that connection or be there for you in another way, in addition to our pregnancy course.

Dear mom, sometimes it’s so crazy that being pregnant. It made me stronger and more decisive than ever, but I also experienced anxious and lonely moments and it’s all part of it. So keep talking! About the beautiful and the difficult. Trust that you are doing it right. For yourself and for that other heartbeat that beats inside you.

Love, Maria.