If a female cat is pregnant with a litter of wee kittens, it's hard to accurately guess just how many little ones her body is carrying. Unlike in humans, single births, although definitely possible, are not the standard in the feline world. Twins are also possibilities in kitten litters.
Kittens as Twins
Kittens can certainly be twins. In some cat breeds, twin-sized litters are extremely common. One such example is the Singapura breed. The dainty felines of this breed typically produce between two and three youngsters per litter -- smaller than the average litter size for cats of all breeds and types. Although twins are especially common in certain cat breeds, they are possible in any and all of them, including both domestic short-haired and long-haired varieties.
Average Litter Size
Twins are possible but not common among cats. Feline litters generally consist of five kittens, according to the Utah Humane Society -- three more than it takes to be considered twins.
Age of the Mother Cat
Smaller feline litters of one, two and three kittens are also more prevalent in younger mother cats who have never bred previously. If a queen is bearing her initial litter, the chance of twins is higher. Once a mother cat begins to get a little older, however, her litter sizes tend to get smaller again -- usually once she's around 6 years old.
Time of the Year
The specific time of year may also have an effect on litter size. Cats are capable of reproducing all year long, whether it's cold, mild or hot outside, although the spring and summer seasons definitely are peak points. Litters tend to be bigger in the summertime, so the chance of a queen bearing twins is higher at other times of the year.
Kittens can be "twins" due to occupying their mother cats' wombs at the exact same time, but they also can be identical twins, meaning they both came into existence thanks to just one sperm and one egg. If two feline siblings have that in common, they are technically twins rather than typical litter-mate siblings, notes feline breeder Jessica Sylvester via the website CatChannel.com.