Chadwick's sign is a bluish discoloration of the cervix, vagina, and labia resulting from increased blood flow. It is considered an indication of pregnancy, and can be observed as early as 6–8 weeks after conception, and its presence is an early sign of pregnancy.
These color changes were discovered in approximately 1836 by Frenchdoctor Étienne Joseph Jacquemin (1796-1872), and are named after James Read Chadwick, who drew attention to it in a paper read before the American Gynecological Society in 1886 and published in the following year, wherein he credited Jacquemin for their discovery.
^ abGleichert, James E. (1971). "Étienne Joseph Jacquemin, Discoverer of 'Chadwick's Sign'". Journal of the History of Medicine and Allied Sciences26 (1): 75–80. doi:10.1093/jhmas/XXVI.1.75. PMID4925842.
^Chadwick, James Reed (1887). "The value of the bluish discoloration of the vaginal entrance as a sign of pregnancy". Transactions of the American Gynecological Society (11): 399–418.