The third trimester

As pregnancy enters the third and final trimester, you may start to feel a bit more like you did during your first trimester. Your nausea might come back and fatigue can kick in from zero to 100 in a matter of seconds. Unlike before, at this point, this is largely because your body no longer looks or functions as it normally does.

When does the third trimester start?

The third trimester begins week 28 and lasts until delivery. But there is no definitive consensus on when it begins: trimesters are mainly a way to organise months. You might therefore read that the third trimester begins a week earlier.
When you leave the second trimester, your body will likely already be bigger, and the remaining time of the third trimester – much of which is about the baby growing – will likely present you with weight gain, fatigue and a longing to meet your baby.

Dizziness and an urgent need to pee – what happens in your body during the last trimester?

You might be achy, and you might feel bulky in a way that affects your mood and your nighttime sleep. Your need to pee was due to hormonal changes before, but now it’s because an active baby is pressing on and kicking your bladder. You might feel a bit more introverted at this point in your pregnancy, and focused on the upcoming labour and life adjustment. You might seem distracted and unfocused to those around you. But that’s completely normal and a very reasonable form of preparation for becoming a parent. That inward gaze might actually cause you to stress less and to take better care of yourself overall.
If you experience dizziness during the third trimester, it might be caused by sleeping on your back, because your now rather heavy uterus can press up against a blood vessel, which can cause dizziness. So try sleeping on your side to see if it helps.

Physical activity and exercise

It’s common to give up any attempts at exercise during the last trimester of pregnancy. It might feel like quite a struggle to shuffle around with a body that feels big, and that is potentially in a bit of pain. But continuing to move will help you feel good and can also support your mood if you’re feeling low. So adapt your workout to how you’re feeling: slow walks (with small, short steps if you’re having pelvic pain), gentle prenatal yoga, or water aerobics – as long as the exercise feels good for your body, then it is good.

How does the baby develop during the third trimester?

The baby has almost finished developing; most of what is necessary for survival outside the uterus is in place and the remaining weeks are primarily for the baby to gain a few kilos and centimetres. During the last trimester, baby will grow from the size of an aubergine to the size of a watermelon. They can hear well at this point, so take the chance to sing and talk to your baby, who will recognise those voices upon being born. And by the way, did you know that babies can already dream and suck their thumbs? They’re also starting to develop a circadian rhythm, which usually stays with them after birth.

When does the third trimester end?

Because the third trimester is the last portion of pregnancy, it ends with the baby’s arrival. Most people are more than ready when it’s finally time, and it isn’t unusual to feel as if you’ve been waiting forever, even if your baby arrives before they’re due. Towards the end of pregnancy, you might be a bit more sensitive to infections and it can be harder to get rid of stubborn colds during the last trimester.

Please note that all information above is based on Swedish recommendations.