What indicates a bluish tint of the vagina during pregnancy?

Chadwick's sign is the correct answer because it specifically refers to the bluish tint or discoloration of the vagina and cervix that occurs during pregnancy. This change is due to increased blood flow and vascularity in the pelvic region as a result of hormonal changes, primarily from estrogen and progesterone. Chadwick's sign is often one of the earliest observable signs of pregnancy and can be noted during a pelvic examination.

In contrast, Hegar's sign is characterized by softness of the lower uterine segment and is indicative of pregnancy, but it does not describe any change in color. Goodell's sign involves the softening of the cervix itself rather than a change in color. McDonald's sign refers to the ease of flexing the body of the uterus against the cervix, again not related to any discoloration. Understanding these signs is crucial for healthcare providers in confirming and monitoring pregnancy.