What to choose between size 1 or 2 diapers when baby is born?

In collaboration with Rokiyah Hosen Professional proofreading


There's a lot to think about when you're expecting a baby, especially when it's your first! Among these many supplies are the famous diapers. Figuring out how many diapers you're going to need, how many packs you're going to need, what you're going to stock up on in advance, etc. can be a real headache... And that's not even counting the diaper size! In this article, we explain what you need to bear in mind when choosing the right size for baby's birth!


What are the differences between size 1 and size 2 diapers?

There are two different diaper sizes to suit the birth of your baby: size 1 and size 2.

Size 1 diapers

The size 1 diaper is designed for newborns from 2 to 5 kg, up to around two months of age. This is the smallest diaper size available.

Size 2 diapers

The diaper size 2 is suitable for babies weighing between 3 and 6 kg, and can be used for up to 3 to 4 months. However, depending on the baby's weight and size at birth, size 2 diapers can be used from birth or shortly afterwards.

Verdict: what size diaper to choose when baby is born?

As you can see, the two sizes overlap in terms of weight. Difficult for parents to choose the right diaper.

We advise you to wait for the last ultrasound before buying diapers for your baby. In fact, it's at the last ultrasound that you'll find out your baby's expected weight. And weight is one of the factors that will help you choose the right size for your diapers.

The second factor to consider when choosing a diaper size is morphology. But this is difficult to predict in advance!

In any case, you'll need a pack of size 1 diapers for your stay in the maternity ward, i.e. for the first few days of baby's life. Even if your baby is expected to weigh 4 kg. The average maternity stay lasts from 3 to 5 days, to smake sure your baby is well looked after. You'll only need one or two packs of size 1 diapers. If your baby weighs 4 kg or more, a single pack of size 1 will suffice, and when you're back home you can go straight to size 2.

During the first few days of life, your baby will lose weight (around 10% of his birth weight). This is perfectly normal, as he loses water as he eliminates his meconium (the first stools). On the other hand, the amount of milk he drinks is very low. 

Your baby will regain his birth weight after 1 to 2 weeks. That's why size 1 diapers are essential for all babies, even if you only need one pack.

For smaller babies or premature babies, there is a size 0, but very few brands offer it. This size corresponds to babies weighing between 1 and 2.5 kg. As your baby grows, you can start with size 1.

When should you change your baby's diaper size?

Generally speaking, size 1 diapers are only needed for the first few days of your baby's life , while he's in the maternity ward. When you return to the maternity ward, depending on your baby's weight and morphology, you can switch to the next size up, size 2. There's no need to stock up on size 1 diapers!

Here are a few signs that it's time to upgrade:

  • If you notice recurrent leaks and an overflowing diaper;
  • If, when you change your baby, you notice red marks on the skin around the waistband of the diaper or on the thighs, this means that the diaper is too tight and potentially too small;
  • If you have trouble fastening the diaper's elastic bands s'they tend to come loose.

When it comes to diapering, you need to change your baby after every feed or bottle, and as soon as he or she has had a bowel movement. It's important to change your baby regularly to avoid any irritation, diaper rash or redness.

How to choose the right diapers for your baby?

Choosing the right size diaper is vital for your baby's well-being, as he'll be wearing them for a long time before he's potty-trained.

But when it comes to choosing a quality diaper for your baby, size is not the only factor to consider. Diapers are in direct contact with your baby's skin, which is highly sensitive and permeable. So it's important to s'interest in :

Ultra-chemical composition-free coating

The composition of the diaper. All the more so when you consider that a few years ago, 60 millions de consommateurs revealed the presence of toxic substances in many baby diapers. 

The French health agency (Agence Nationale de la Sécurité Sanitaire) then examined the composition of disposable diapers and came to the same conclusion, namely that many diapers contain chemical substances that are hazardous to the health of newborns, even exceeding authorized health thresholds.

No one wants to put their baby in toxic diapers. So, to avoid chemical substances, we recommend organic cotton diapers.

To ensure that the eco-friendly, organic diaper you choose for your baby is safe, there are several things you can refer to: 

  • The manufacturing process: most disposable diapers bleach the cellulose with chlorine dioxide using the ECF (Elementary Chlorine Free) method. 5% of diapers (ecological diapers) are bleached using the TCF method (Totally Chlorine Free), which is the most respectful method for lhumans, as it uses no chlorine or chlorine dioxide compared to the ECF method. For a high-quality diaper that's kind to your baby, choose the TCF method;
  • An eco-friendly diaper brand that's good for your baby's skin should be transparent about its composition and manufacturing methods, and chemical analysis reports should be accessible. If you can't find the chemical analysis reports, that's not a very good sign;
  • Organic diapers must not contain toxic or harmful residues or undesirable or carcinogenic substances such as glyphosate, volatile organic compounds, dioxins, furans, perfumes, pesticides, allergens or latex (in elastics);
  • For a healthy and respectful diaper, endocrine disruptors should also be banned;
  • A good ecological diaper also favors natural raw materials, which are softer and more comfortable for your baby's bottom, but also more respectful of the environment. The most important thing is that your baby's skin should be in direct contact with natural, biodegradable materials made from natural fibers, rather than plastic. Remember to check the composition of your diaper, as well as the percentage of natural fibers!

Absorption capacity

Having a diaper with impeccable absorbency is very important for your baby's comfort and to avoid leaks. Ecological diapers are just as absorbent as chemical diapers. They generally add natural cellulose to the absorbent layer, as they reduce the amount of SAP (sodium polyacrylate, an absorbent synthetic material with no more natural alternative) absorbent beads.

Choosing a good diaper for baby means choosing a diaper that's right for him, healthy and respectful of his skin, absorbent and comfortable.


Size 1 or 2 birth diaper FAQs

When to switch from layer size 1 to size 2?

Size 1 diapers are suitable for the first few days of your baby's life. Depending on weight and morphology, you can switch to size 2 more or less when you return home from the maternity ward.

How do you know if your baby's diapers are too small?

If you notice leaks and red marks on your baby's skin, and you have trouble getting the elastic to stay in place, his diaper is probably too small.