There are a lot of possible answers to this question, so I always need more information to answer it.
- Does the diaper fit correctly?
The diaper should not gap away from the baby's skin anywhere on the legs or waist. You should have to stretch the elastic aside in order to get one finger between the diaper and the baby. Also check for gaps when the baby is in different positions - a common culprit is when the baby is sitting upright, the legs can gape at the crotch. For boys, a diaper that is too low-cut in the front can cause leaking since their pee is aimed towards the front.
- Is the diaper or pocket insert completely soaked when it begins to leak?
Then change the diaper more often. Diapers will leak if they are completely saturated and the baby pees again.
- Does it leak when the insert is not saturated?
This happens because the pee is running off the inside of the diaper before it can soak in. This can be caused by three factors:
1. Buildup on the diapers is causing the diaper to repel the pee before it can soak in. The solution is to strip the diapers - wash them several times on hot with no detergent to work out the excess detergent.
2. Toddlers often have this problem because they drink a lot of liquids and they hold their pee for longer, so when they do pee, it comes out very quickly and forcefully, called "flooding." This is usually only a problem with pocket diapers as the stay-dry inner layer requires a few moments for the pee to pass through. This stage of the baby's development usually passes, but it can be solved by using natural-fiber pockets or all-in-ones or fitteds and covers.
3. If it happens while lying down in a pocket, it can be because the pee rolls inside the diaper to an area where there is no insert inside (like the wings.) The solution would be to not use a pocket for times when the baby will be lying down.
- Does it leak only at night?
Babies can contort themselves into weird positions at night, and if they sleep for longer and still nurse at night, there is a lot of pee for a diaper to contend with! We have a page of night-time diapering solutions, but in general, using a fitted with several doublers and a pull-on style cover made of fleece or wool will be your best bet.
- Does the leaking seem to come right through the outer fabric everywhere?
This is usually waterproofing/PUL failure, usually caused by excessive bleach or really harsh washing methods. If you look at the inside of the waterproofing, instead of being smooth and clear or slightly whitish, it will be cracked, ripped or peeling, and sort of look like a peeling sunburn. This cannot be fixed, but it is sometimes a manufacturing defect and may be covered under the manufacturer's warranty.