Answer:
In pregnancy, the kittens are spaced along each horn of the uterus. Each kitten is contained within its own membranes and has its own placenta through which it derives nourishment. The uterus may be considered as a muscular, sausage-shaped bag, capable of contracting both around its diameter and along its length. To help in its passage, each kitten is contained within a fairly tough double-layered bag of membranes, which are filled with slippery fluid in which the fetus floats. This serves as both protection and lubrication and provides a distending, stretching and dilating force when the uterus relaxes in front of it and contracts behind it during the course of birth.
