Yes, prewash the nappies up to 50ºC to remove manufacturing residues before your baby wears them.
Use a simple plain detergent that has no softeners, no brighteners, no enzymes and no additives to ensure that the nappy stays absorbent and non-irritating to your baby.
It can take up to 5-6 washes for most absorbent fabrics to become at their most absorbent.

NOTE: Just make sure the nappies are the right fit and the right size before you wash them, so that you can exchange them for another size if they don't fit. Washed or worn nappies cannot be exchanged or returned.