Chadwick’s sign is a physical indicator of pregnancy that can occur as early as the sixth week. It is a change in the color of the labia, vagina, and cervix as they start to fill with blood in response to changes in hormone levels. They start to turn purple or bluish, indicating that vascular congestion is occurring. There are more reliable methods for diagnosing pregnancy, but signs like this can interesting for pregnant patients and they were once very important when people didn’t have access to blood and urine testing.
This obstetrical sign may onset at various points, depending on the individual. Patients may notice some physical swelling associated with the engorgement as blood rushes to the area when the hormones begin to change. Discoloration can also appear in other areas of the body; for example, pregnant patients experience a distinctive dark line down the abdomen known as the linea nigra, and some patients may notice changes in facial color. The skin can change in texture as well as color.
A physical examination early in pregnancy may reveal Chadwick’s sign along with other indicators, like increased puffiness and tenderness in the nipples. As the pregnancy progresses, these indicators can become more pronounced and the patient may start to notice abdominal swelling as the developing fetus forces the uterus to expand. Pelvic pain and swelling in the legs can also occur as the pelvic region prepares for delivery and the circulation of the blood and lymph is disrupted.
Patients may notice Chadwick’s sign if they pay close attention to their genitals, as may be the case with people who have fertility problems and closely monitor cervical mucus and other indicators of ovulation. A doctor can also show the patient during a physical examination with the assistance of a mirror to help the patient see the internal color changes. Some patients like to chart the progress of various clinical signs of pregnancy and can ask if they want more information.
Indicators like Chadwick's sign were used by physicians for centuries in the early diagnosis of patients, as well as being passed down among women who wanted to be able to spot pregnancy early. The identification of indicators like Chadwick’s sign helped physicians more accurately identify early pregnancies so they could advise patients on how to proceed with prenatal care and preparations for delivery. Early diagnostic techniques were not always accurate and it was sometimes hard to pinpoint delivery dates. When researchers specifically identified hormones associated with pregnancy and developed tests for them, this became the preferred method for diagnosing pregnancy.