The average number of days a cat (known as a queen) is pregnant is 63 (or 9 weeks), but birth can occur anywhere between the 60th and 70th day. There are some signs that she may be close to giving birth (known as "queening"). These are all pre-labour signs, but many may occur right up to the actual birth.
Birth is divided into three stages:
First stage - The beginning of uterine contractions.
Second stage - Contractions become stronger until she delivers her kitten.
Third stage - Delivery of the placenta.
So, what are the signs that a cat is close to giving birth?
Swollen nipples and milk discharge: In the days leading up to the birth, her nipples will increase in size, around two days before she gives birth, they will produce milk. You may be able to express some out by gently squeezing the nipples between your thumb and forefinger.
Her personality may change: Often queens become quite clingy and affectionate with their owner right before labour. She may purr, lick you, follow you around the house. On the other hand, a normally friendly cat may withdraw and spend more time on her own. Both of these changes are completely normal. It should be mentioned that in the final two weeks before delivery, she should be left alone if that is what she wants. Many cats have a favourite person, and they can check up on her, but now is not the time to let children or strangers come and pester her unless that is what she is happy with.
She will start nesting: Seeking out a quiet and safe spot for her to deliver her kittens. The pet owner should have already prepared a nesting box for the queen, although sometimes the queen herself will choose another location. Common spots queens choose is the back of a wardrobe or inside drawers. She may rest in her nesting box and knead with her front paws. A nesting box should be provided for the queen two weeks prior to delivery so she can settle in. It should be in a quiet but warm spot, out of the way of children and other pets. She needs to feel safe in her nesting box.
Pacing, restlessness, and more vocal: All are are common in the immediate hours before birth.
Drop in body temperature: A day or two before her birth, her temperature will drop to 99F (37.2C). The normal temperature is 100 - 102F (37.7 - 39.1C).
Genital licking: This is a sign that delivery is very close.
Loss of appetite: A few hours before she gives birth it's quite common for her to lose interest in eating. She should be provided with food and water at all times, however.