The most common cause of leakage is fitting your baby with the wrong nappy size. So start by checking if the nappy size is right for your baby. Note also that the amount of pee increases as your baby grows. By the time your baby is 12 months old, the amount of pee discharged in a day will be twice that of a newborn. While the nappy size may appear to fit your baby, the amount of pee may have increased with his growth, so the nappy may not be able to absorb the larger amount of urine. For disposable nappies, the bigger the size, the better the absorbency. If you notice frequent leakages, it may be time to change the nappy to a larger size.
If there is leakage even though you have fitted the nappy properly on your baby, do a check for the following:
Why is baby's nappy leaking?
Advice for leakages from different parts of the nappy
When placing the nappy under your baby's bottom, make sure you pull the nappy high enough to prevent leakage. Raise the back portion slightly higher than the front portion and then fasten the tape diagonally downward.
Make sure that the nappy edges are not folded and that tape is fastened evenly. If you notice that the position where you fasten the tape is out of the marked area, it's time to change the size of the nappy. Try using one size bigger.
Pull the nappy straight and high enough to reach the belly button area. Adjust the gathers around the leg area so that they fit properly around the crotch area. Make sure the gathers are pulled outwards. If the leakage continues when your child is strapped onto a seat belt, try to fasten the nappy tape at a lower level, slightly slanted at an angle.
Raise the front portion of the nappy slightly higher than the back portion and fasten the tape slanting upwards so that the belly button is hidden. For boys, make sure the penis is pointing downwards.