A woman is a female human. The term woman is usually reserved for an adult, with the term girl being the usual term for a female child or adolescent. The term woman is also sometimes used to identify a female human, regardless of age, as in phrases such as "women's rights". "Woman" may also refer to a person's gender identity. Women with typical genetic development are usually capable of giving birth from puberty until menopause. In the context of gender identity, transgender people who are biologically determined to be male and identify as women cannot give birth. Some intersex people who identify as women cannot give birth due to either sterility or inheriting one or more Y chromosomes. In extremely rare cases, people who have Swyer syndrome can give birth with medical assistance. Throughout history women have assumed or been assigned various social roles.