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The early years of life are an extraordinary period of discovery, learning and change.
There baby grow is the most worn clothing item in the first months of life. Every baby has several — but choosing the right one involves understanding the differences in format, material, fastening and size. This complete guide helps you kit out baby wisely from birth to 18 months. 🐸
A sleepsuit (also known as baby pyjamas, a onesie or a sleepsuit) is a one-piece garment that covers a baby’s entire body, from the feet right up to the neck. It differs from the bodysuit in that it has long legs with integrated feet. It is the standard night-time garment for infants and babies up to 18–24 months.
The most common format: it covers the whole body including the feet. Ideal for the night as it prevents baby from uncovering themselves. Non-slip feet are very useful as soon as baby starts to stand up.
Much appreciated innovation: a two-way zip. For night-time nappy changes, opening only the bottom part avoids having to undress baby completely — essential to avoid waking them up fully at 3 am.
More versatile, it makes it possible to add booties depending on the temperature. Practical in summer or as daywear.
Magnetic fasteners allow for silent and ultra-fast dressing, even in the dark. Ideal for parents changing baby at night without turning on the light.
The ultimate standard for delicate infant skin. Soft, breathable, hypoallergenic, free from chemical residues. The top choice for sensitive skin.
Thicker and softer knit than standard jersey. Slightly warmer — ideal for transitional seasons. Resistant to repeated washing.
For winter nights: provide superior warmth. To be worn with a sleeping bag with a TOG rating suitable for the room temperature.
Ultra-soft, thermoregulating, antibacterial. Particularly recommended for babies who sweat easily or have eczema-prone skin.
Babygrows often run slightly small – the built-in feet limit how long they can be worn. When in doubt, always size up.
The romper suit should not be worn on its own in cool weather — it should be worn with a sleeping bag. The principle is: a lightweight romper suit + a sleeping bag suitable for the season’s TOG rating. Never use a blanket over the top before 12 months.
Before 18 months, the babygro is recommended: it doesn't come undone and doesn't ride up during the night. The two-piece pyjamas present the risk that the top rides up and exposes the baby's tummy. The babygro maintains an even layer over the whole body, which paediatricians recommend to prevent nighttime chilling.
From around 18-24 months, when the child is more independent and starts undressing on their own, two-piece pyjamas can gradually take over.
Allow for 5 to 7 babygrows per size. Night-time messes (spit-up, nappy leaks) often mean changing baby during the night. With 6 babygrows, you have some leeway even if the washing takes a day. Focus your purchases on 3 months and 6 months — the newborn size is worn for a very short time.
A well-cared-for organic cotton babygrow can last two or three children. That is yet another reason to invest in quality rather than quantity.
To dress baby consistently, also find our guide on the bodysuit baby — the essential base layer to be worn under the sleepsuit in cool weather — and our advice on dressing baby in summer.
Yes, especially in the first few months. Rompers aren’t just for night-time — lots of parents dress their babies in rompers all day long. From 3–4 months onwards, you can mix things up a bit more with daytime outfits (size bodysuit + trousers, playsuits).
In cool weather (room temperature < 20°C): yes, a short- or long-sleeved bodysuit provides an extra layer of warmth. In hot weather (room temperature > 22°C): the romper on its own is sufficient.
Not if the size is right. A babygrow that is too short and pulls on the feet can hinder hip development. Always make sure the feet have room and that the crotch is not too tight.
The two complement each other. The sleepsuit is the night-time garment. The sleep sack (or sleeping bag) is the blanket worn over it. Together, they make up the ideal night-time outfit according to French paediatric recommendations.
Soft cotton rompers, double-zip designs, adorable patterns and OEKO-TEX-certified fabrics: PetitMaxou offers a comfortable and practical range for your baby’s first few months. Free delivery throughout the EU, returns within 14 days.
→ See all PetitMaxou baby rompers and baby clothes
A set of 3 to 5 organic cotton baby grows in a pretty box is one of the most popular new baby gifts — immediately useful, used daily, and often not thought of by parents-to-be who focus on the big items (pushchair, cot). If you are looking for other ideas to complete your gift, our selection of original newborn gifts is a good source of inspiration. Choose 3-month size rather than newborn — the newborn size is worn for a very short time and often already received in triplicate.
The early years of life are an extraordinary period of discovery, learning and change.
Baby sunscreen is one of the summer essentials for young parents —