According to the Southern Hamster Club, dwarf hamsters typically are pregnant for 18 days although the gestation period sometimes extends up to 25 days. The average litter size is four, but as many as 10 babies are possible. Large litters often have high mortality rates.
The Small Animal Channel explains that dwarf hamsters, or pups, are born blind and hairless. After about two weeks, they have fur and open eyes, and they move around on their own. Though pups are still nursing, they're able to start on solid foods. By 3 weeks old, pups are fully weaned. Between the ages of 3 1/2 and 5 weeks, pups need to be removed from their parents' home with males and females placed into separate cages.