The labia majora and the labia minora cover the vulval vestibule. The onset of vasocongestion results in swelling of the clitoris, labia minora, and vagina. The onset of vasocongestion results in swelling of the woman's clitoris, labia minora and vagina. Females have a thick, elongated clitoris that protrudes from the labia of the vulva. Between the labia majora and labia minora are the interlabial sulci. External genitalia is normal, although the labia and clitoris are sometimes underdeveloped. The labia minora become less prominent. At birth, she had a genital malformation (a fused labia and deformed clitoris). The labia minora increase considerably in thickness. Pregnancy may cause the labia minora to darken in color. The scrotum is developmentally homologous to the labia majora. It has a hood formed by the labia minora (inner lips). They meet posteriorly at the frenulum of the labia minora, a fold of restrictive tissue. The scrotum is biologically homologous to the labia majora in females. These were somewhat loose and resembled labia majora.