Pregnancy
What you need in the first trimester
The first trimester in practice. Folic acid and vitamin D, tiredness and nausea, your first visits to the gynaecologist, clothes, and what not to buy yet.
2 min read
How your body changes during pregnancy
Pregnancy is divided into three trimesters. Each has its typical changes, and each calls for slightly different clothes, a different rhythm to the day and different preparations.
The three trimesters at a glance
The NHS divides pregnancy like this: the first trimester runs to week 12, the second from week 13 to week 27, and the third from week 28 until the birth.1 Weeks are counted from the first day of your last period, so “week 4” means roughly the time of the missed period.
| 1st trimester | 2nd trimester | 3rd trimester | |
|---|---|---|---|
| Weeks | up to 12 | 13–27 | 28 to the birth |
| Common changes | tiredness, nausea, tender breasts, needing to wee more often2 | the bump starts to show, first-trimester symptoms often ease1 | the bump grows fastest, sleep gets harder, less room for the stomach |
| Baby’s movements | you can’t feel them yet | first movements; if you have not felt any by week 24, tell your doctor or midwife3 | you know their pattern; report any change straight away3 |
| Clothes | a soft bra, a stretchy waistband | first maternity leggings and tops | layers that open, a coat or an insert |
| Preparations | supplements, first visits to the gynaecologist | baby kit, clothes, a sling or carrier | hospital bag, car seat, documents |
The first trimester
Nothing shows on the outside, but your body is working flat out. More in the article What you need in the first trimester.
The second trimester
For many women this is the most pleasant stretch: the worst symptoms of the first trimester often ease and the bump starts to show.1 It is a good time for:
- your first maternity clothes, ideally ones that open for breastfeeding (guide),
- thinking through the baby kit (complete list),
- choosing and trying out a sling or carrier (wrap or carrier).
The third trimester
The bump grows and the space shrinks. Sleep may be harder and movement slower. The NHS recommends packing your hospital bag at least three weeks before your due date.4 In detail in the article Getting ready for the third trimester.
Your body after the birth
The bump does not disappear straight away. In the first weeks you will be comfortable in maternity trousers and in tops that open for breastfeeding. That is why it pays to buy maternity pieces with the time after the birth in mind as well.
Where this comes from
The numbers in the text refer to these sources. The links go to the publishers’ own pages; we simply cite them.
- NHS (United Kingdom):Week-by-week guide to pregnancyFirst trimester weeks 4–12, second 13–27, third 28–41.
- NHS (United Kingdom):4 weeks pregnant – early pregnancy symptoms
- NHS (United Kingdom):Your baby's movementsIf you have not felt movements by week 24, tell your midwife; if the movements change, call straight away.
- NHS (United Kingdom):Hospital bag checklist
We last checked these sources on 13 October 2026.
Further along the path
Pregnancy
Getting ready for the third trimester
A practical plan for the third trimester. The hospital bag, documents and acknowledging paternity, the car seat, baby kit, a sling or carrier, nursing clothes, and what to watch for with your baby’s movements.
3 min read
Clothes
Maternity clothes – the complete guide
What to buy, when and in what size. A wardrobe for three trimesters, fabrics, cuts that last beyond the birth, and things that aren’t worth it.
In-depth guide 6 min read