Newborn kittens should not be handled unless absolutely necessary for their health, according to Purina. The mother needs time to care for her kittens when they are born, including breaking the amniotic sac and biting through the umbilical cord. The mother also needs time for cleaning and feeding.
Kittens should also not be over-handled during their first week, as this could upset the mother, according to the American Society for the Prevention of Cruelty to Animals. The period between weeks two and seven is an important period for socialization. This is a good time to begin gently handling kittens to socialize them with humans. Kittens need to be handled with special care to avoid injury, and young children handling them should be closely supervised.
Until eight weeks of age, kittens are unable to regulate their own body heat and require the warmth provided by the mother and littermates, explains Petfinder. At eight weeks, kittens are usually weaned, eating kitten food and becoming more active as their motor skills improve.
On average, kittens weigh about 3 1/2 ounces at birth and gain steadily over the first weeks of life as their weight doubles or even triples, as reported by the ASPCA. Gaining adequate weight during the first eight weeks is essential for a kitten's survival.