Here’s the thing: There’s no such thing.
Potty training—like sleep training—typically requires picking a method and committing to it. Some parents opt for a hard-core, three-day at-home intensive of pantlessness, mad bathroom dashes and plenty of accidents. Others take a laissez-faire stance and trust nursery school peer pressure to do away with diapers once their kids are ready (here’s to communal peeing and toddlers’ utter disregard for privacy).
Yet there is much murkiness around how to potty train kids at night. Well, let us shed some light: You don’t have to! This is one area of parenting where you can literally do nothing and still give yourself all the gold stars. Kids will awaken with the urge to urinate (or hold it in until morning) on their own, when—and only when—they are physiologically ready. And doctors say there is no way to predict exactly when this will happen (though it tends to around age four, on average).
Still, "Nighttime control can lag behind daytime control by a few months to a few years," [emphasis ours] pediatric urologist Dr. David Joseph tells Parents. It is not uncommon for kids (especially boys) who were potty trained at age three to still sleep in pull-ups at six or even a bit beyond—particularly if they are heavy sleepers. Kids who wet at night do so simply because, as one medical publication puts it, “the ‘wiring’ which allows a full bladder to ‘yell loudly enough’ at the brain to wake the child and make them go to the toilet isn’t fully mature yet.” Even at age seven, two kids out of 30 will still be wet at night.