And finally, the hair also may or may not grow. So these three trimesters basically divide the three different stages of the gestation period, the period during which that female individual is pregnant. Now, what about the birth process? Well, the birth process, also known as parteration, can also be broken down into three stages. We have stage number one, which lasts about 12 hours. We have stage number two, which lasts from anywhere from 20 minutes to 1 hour.