A newborn's diaper has a different job from the diaper of an 8-month-old baby. In the first weeks the baby weighs between 2.5 and 4 kg, poos many times a day, has an umbilical stump that is healing and skin that reacts to almost everything. So "the best diaper" for this stage is neither the most absorbent nor the cheapest: it is the one that fits a small body well, protects the belly button, keeps the skin dry and does not force you to buy half the shop to find out. This guide explains how to choose, compares the options we have in store and sums up what changes over the first 30 days.
The four criteria that matter for a newborn
- Fit for the baby's actual weight. Sizes are defined by weight ranges, and a newborn may be born weighing 2.6 kg or 4.2 kg. The diaper has to fasten without stretching and leave room for two fingers at the waist.
- Belly button protection. Until the stump falls off (usually between 10 and 20 days), the diaper should not rub or cover the area. Some Size 0 and Size 1 diapers have a cut-out at the front; with others, you fold the front down.
- Dry skin and no friction. A soft interior, no fragrance, gentle side barriers. A newborn's skin is irritated mainly by prolonged moisture and friction, not by "chemicals" in general.
- Easy changing. With 8 to 10 changes a day, a wetness indicator and refastenable tabs save time and mistakes, especially at night.
Size 0 or Size 1: which to choose
This is the most common question before the birth, and the answer depends on birth weight:
- Size 0 (1-2.5 kg or 1-3 kg, depending on the brand): for premature babies or those under 2.5 kg. Most full-term babies skip this size or use it for only a few days.
- Size 1 (2-5 kg or 2-4 kg): the newborn size for the vast majority. It typically lasts between 3 and 6 weeks.
- Size 2 (3-6 kg or 4-8 kg): a baby born at 4 kg or more may move to Size 2 in the first weeks.
The practical rule: if the baby's weight is in the upper half of a size's range, buy only a little of that size and already have the next one at home. We explain the differences in detail in newborn diapers vs Size 1.
Comparison of the newborn diapers we sell
Prices in our store in September 2026; availability of the smallest sizes varies a lot, because they are the first to sell out.
| Diaper | Weight | Units | Price | Per diaper | Best for |
|---|---|---|---|---|---|
| Dodot Sensitive Size 0 | 1-2.5 kg | 24 | €5.58 (€7.99) | €0.23 | Premature babies and babies under 2.5 kg |
| Bambo Nature Size 0 | 1-3 kg | 24 | €6.84 | €0.29 | Eco-friendly option for small babies |
| Dodot Sensitive Size 1 | 2-5 kg | 44 | €9.80 | €0.22 | Starter pack to try out |
| Dodot Sensitive Size 1 | 2-5 kg | 116 | €23.80 | €0.21 | Box for the first month |
| Bambo Nature Size 1 | 2-4 kg | 22 | €6.00 | €0.27 | Eco-friendly, no fragrance or lotion |
| Moomin Baby Size 1 | 2-5 kg | 25 | €6.99 | €0.28 | Sensitive skin, good value for money |
| Moomin Baby Size 2 | 3-6 kg | 56 | €16.99 | €0.30 | Babies born at 4 kg or more |
What sets each one apart in practice:
- Dodot Sensitive is the benchmark for newborns in Portugal: a very soft interior, a belly button cut-out in Sizes 0 and 1, a wetness indicator and the widest range of packs. See the Dodot Sensitive collection.
- Bambo Nature is the eco-friendly choice: certified, fragrance-free, lotion-free, with pulp from sustainable sources. It costs a little more per diaper in small packs and the same as Dodot in large packs. See the Bambo Nature collection.
- Moomin Baby is a Nordic diaper designed for sensitive skin, dermatologically tested, with a stable price per unit across sizes. See the Moomin Baby newborn collection.
All Size 0, 1 and 2 options are gathered in the newborn diapers collection.
What changes in the first 30 days
Days 1 to 7: fit and belly button
The baby loses up to 10% of their weight and regains it in about a week. The umbilical stump is fresh. At this stage the priority is for the diaper not to touch the belly button (cut-out or folded front) and to fasten without squeezing. Poo is dark and sticky (meconium) and the diaper is changed 8 to 10 times a day. A pack of 24 to 44 diapers is enough for the first few days.
Days 8 to 20: frequent stools and reactive skin
Once breastfeeding is established, many babies poo at every feed. The diaper has to contain runny stools, and well-opened side barriers make all the difference. This is also when the first redness appears; changing straight after a poo and drying the skin folds well solves most of it. We have an article on which diaper to choose when your newborn poos a lot.
Days 20 to 30: the stump falls off and the size starts to get tight
The belly button has healed and the diaper can come back up. A baby born at 3.5 kg is now close to 4.5 kg, and marks at the waist or thighs are the sign that Size 2 is near. If there are leaks at the back, it is almost always the size and not the brand. The guide on how to choose the right size has the full list of signs.
How to choose without buying half the shop
Before the birth, buy a small pack of Size 1 from one brand (25 to 44 units) and, if you want to compare, a second small pack from another. Use each for 48 hours and note three things: where leaks appear (back, legs, front), whether the skin gets marked or red, and whether the tabs fasten with room to spare. The winner is the one that passes all three. Only then buy the large box, which works out 20 to 30% cheaper per diaper. For quantities, see how many diapers to buy before the birth.
The most common mistakes (that make a good diaper look bad)
- Fastening too tightly to "prevent leaks". It leaves marks and solves nothing; leaks come from the barriers, not the waist.
- Side barriers folded inwards. This is the number one cause of leaks at the legs. Run your finger along both barriers after fastening the diaper.
- Buying a large box before the baby is born. If the weight or brand does not suit, you are left with 100 unused diapers.
- Switching brands at the first sign of redness. In the first days, redness almost always comes from how often you change and from moisture, not from the diaper. See diapers for sensitive skin.
- Covering the umbilical stump. It delays healing and can become infected. We explain belly button care in another article.
- Tight clothes on top. Tight bodysuits push on the diaper and open the barriers.
Disposable or reusable for a newborn?
Both work. Disposables win in the first weeks for practicality, fit on very small babies and the wetness indicator, which helps first-time parents. Reusables pay off once the routine settles and the baby passes 4 to 5 kg. Many families start with disposables (eco-friendly or not) and introduce reusables in the second month. We compare the two in disposable vs reusable diapers.
Changing routine in the first weeks
During the day, change the diaper every 2 to 3 hours and always straight after a poo. At night, if the diaper is just wet and the baby is asleep, you can wait for the next feed; if there is poo, always change. Wipe from front to back, dry the skin folds well and leave the skin to air for a minute before fastening. The step-by-step guide is in how to change a newborn's diaper. If you want to know how many diapers this adds up to per month, see how many diapers a baby uses per month.
Frequently asked questions
What is the best newborn diaper in Portugal?
For most babies, Dodot Sensitive Size 1 is the safest choice thanks to its fit, belly button cut-out and availability. If you prefer an eco-friendly diaper, Bambo Nature Size 1; for very sensitive skin at a good price, Moomin Baby Size 1. Ideally, test two with a small pack.
Should I buy Size 0 before the birth?
Only if the scan suggests a weight under 2.5 kg or if there is a risk of premature birth. Otherwise, buy Size 1 and a small pack of Size 2 as a backup.
How many diapers does a newborn use per day?
Between 8 and 10 in the first weeks, which means 250 to 300 in the first month.
How do I know the diaper fits properly?
It fastens without stretching, two fingers fit between the waistband and the tummy, the leg barriers are turned out and the front sits below the belly button until the stump falls off.
Can the diaper cause diaper rash?
Rarely the diaper itself; the usual cause is moisture and stools in contact with the skin for too long. Frequent changes, careful drying and a protective barrier cream solve most cases.
Summary
Choose by your baby's actual weight (Size 1 for almost everyone), protect the belly button until the stump falls off, test two brands with small packs for 48 hours and only then buy the large box. Dodot Sensitive, Bambo Nature and Moomin Baby all serve a newborn well; the difference lies in your family's priority: availability and belly button cut-out, eco-friendly footprint or stable price. You will find them all in the newborn diapers collection.
