I want to stop using diapers for my three year old in the night, but afraid that it would affect his sleep. Should I wait?

Don’t worry if you've left a gap between daytime potty training and getting them dry at night. This is completely normal: most pre-schoolers aren’t toilet trained at night until aged three or sometimes nearer four. You’ll know when the right time is to start. Sometimes your little one may tell you that they do not want to wear diapers anymore and yes, this is the time. The other sign is that their nappies are dry or nearly dry for several nights in a week. That means they’ve got the physical maturity to go a whole night without weeing. However, this is not always a reliable indicator - sometimes they use their night nappy for an early morning wee because they know it’s there, which is perfectly logical. You may wish to start with using pull-ups and say you think they are old enough to go to the loo or use the potty at night. They might be very happy about it too.