The more babies a woman is carrying, the more likely it is that her uterus will swell, triggering contractions, says Brian Brost, M.D., associate professor of maternal/fetal medicine at the Mayo Clinic, in Rochester, Minnesota. An early due date isn't the only challenge to having multiples.
Dogs do not menstruate like humans do. Instead, they come into estrus (come into heat/season) about twice a year, once they have reached sexual maturity. This can sometimes be associated with a small amount of blood from the vulva, but it is not truly a period. Female puppies can reach sexual maturity potentially as early as six months old, although the first season (which is the closest equivalent to getting their period) is often at about nine months old.
The average length of the reproductive cycle for females is 2â4 weeks. Females reach sexual maturity (puberty) between 8 and 18 months of age.There is a tremendous variability in the maturation age between breeds, and even within a breed of dog.he average length of the reproductive cycle for females is 2â4 weeks. Females reach sexual maturity (puberty) between 8 and 18 months of age.