Baby clothes are sold in months. Babies, unhelpfully, are born in kilograms — and the gap between those two facts accounts for most of the newborn clothing that never gets worn.
An average British baby arrives at around 3.5 kg. But the healthy range at term runs from roughly 2.5 kg to 4.5 kg, which is nearly double from one end to the other. Two babies born on the same morning can need different sizes on the same day, and neither of them is unusual.
So the useful question is not how old the baby will be. It is how much the baby will weigh.
What the labels actually mean
Most European babywear, ours included, maps to weight rather than to a birthday:
Newborn — up to about 4.5 kg, or roughly the first three to four weeks. 0–3 months — about 4.5 to 6 kg. 3–6 months — about 6 to 8 kg. 6–12 months — about 8 to 10 kg.
A baby born at 4 kg may skip newborn altogether and start in 0–3. A baby born at 2.8 kg may live in newborn for six or seven weeks. Both are entirely normal, and neither is a sign that anything has been bought wrongly — only that months are a blunt instrument.
What to buy before the birth
Two sizes, and not many of either.
A small number of newborn pieces — four or five, no more. If the baby is large they will be worn for a fortnight; if the baby is small they will be worn for a month and you will be very glad of them. Either way this is not the size to stock up on.
A proper set in 0–3 months — this is the size that does the real work. Almost every baby passes through it, most of them for eight to ten weeks, and it covers the period when you are least likely to want to be shopping.
Everything beyond that can wait. Babies grow at their own pace, seasons change, and a drawer of 6–12 month clothes bought in advance is a drawer of clothes that will be the wrong weight for the weather when the time comes.
Why the fabric matters more at this size
A newborn's skin is around a fifth of the thickness of an adult's, and it spends the first weeks learning to regulate temperature and moisture on its own. What sits against it is not a small consideration.
Everything we make is 100% organic Egyptian cotton — the softest cotton in the world. The fibre is long-staple, which means fewer joins in the yarn, fewer loose ends against the skin, and a fabric that stays smooth rather than pilling into roughness after a fortnight of washing. It is GOTS certified, so nothing harsh has been used at any stage between the field and the drawer.
It also has a practical advantage at this size: long-staple cotton holds its shape. A newborn bodysuit that has been washed twenty times still fits over the head the way it did on the first day, which matters a great deal more at three in the morning than it does in a shop.
Buying for someone else
If you are choosing a present before the baby arrives, buy 0–3 months rather than newborn. It is the size the parents will be short of, it will fit whatever the birth weight turns out to be, and it arrives at the point when the first wave of gifts has been outgrown and nobody has had a moment to replace them.
The other kindness is to buy something that opens easily. Which is a whole subject of its own, and one we take up next.
