Low birthweight is defined as less than 2,500 grams (up to and including 2,499 grams).
Birthweight is the first weight of the newborn obtained after birth. For live births, birthweight should preferably be measured within the first hour of life, before significant post-natal weight loss has occurred.
Method of estimation:
Numerator: The number of live births in a given population and over a given time period that weigh less than 2,500 grams
Denominator: Total number of live births in the given population during the same period