Chadwick Sign

What is the Chadwick sign (Chadwick’s sign)?

The Chadwick sign is a potential early sign of pregnancy where your vulva, vagina and cervix turn a bluish color. Sometimes, your genitals look purplish or purplish-red. You may notice this change or your gynecologist may notice the Chadwick sign during a physical exam. It’s considered a non-specific pregnancy symptom. This means that you could be — not that you are — pregnant.

The Chadwick sign usually appears six to eight weeks after conception, when sperm fertilizes an egg. But the bluish discoloration can show up as early as four weeks. This timeline corresponds with changes in your reproductive system to support a pregnancy. The Chadwick sign disappears during pregnancy or shortly after delivery.

What causes the Chadwick sign?

Increased blood flow to your genitals, vagina and cervix cause the Chadwick sign. The blue hue is just how blood-filled veins appear beneath your skin. Blood volume and blood flow increase in these areas during pregnancy. You need more blood to carry oxygen and nutrients to your reproductive organs and the developing fetus.

Other signs you might be pregnant often arise alongside the Chadwick sign.

Goodell sign

The Goodell sign is the softening of your cervix. Your cervix connects your uterus (where the fetus develops) to your vagina (where your baby leaves your body during childbirth). In early pregnancy, blood vessels enlarge, and new blood vessels form in your cervix. They fill with more blood. All these changes cause your cervix to soften, making it easier for your baby to pass through to your vagina during birth.

Your gynecologist may notice the Goodell sign within the first four to eight weeks of pregnancy.

Hegar sign

The Hegar sign also involves the softening of your cervix and is usually noticeable between weeks four and eight. It involves the softening of a particular part of your cervix called the cervical isthmus. This is the part of the cervix closest to your uterus.

Does the Chadwick sign indicate pregnancy?

The Chadwick sign means you could be pregnant, not that you are. You can be pregnant without the color changes. Also, the appearance of your genitals can change for reasons unrelated to pregnancy.

Still, the Chadwick sign has been an informal indicator of pregnancy for centuries. It’s one potential change in your body your healthcare provider may look for to see if you may be pregnant.

History of the Chadwick sign to diagnose pregnancy

Healthcare providers have known about the Chadwick sign since the early 19th century. A French doctor named Etienne Joseph Jacquemin linked the bluish discoloration to pregnancy while treating imprisoned sex workers.

Years later, an American doctor named James Read Chadwick presented Jacquemin’s observation to the American Gynecological Society in 1886 in a paper called “The value of the bluish discoloration of the vaginal entrance as a sign of pregnancy.” The Chadwick sign is named after him.

The Chadwick sign in pregnancy today

The Chadwick sign alone isn’t a reliable indicator of pregnancy. But if it happens alongside other common early pregnancy symptoms, it may be time to take a pregnancy test or schedule a visit with a provider. Other symptoms to watch out for include:

• A missed period.
• Having to pee more.
• Fatigue (feeling tired even with rest).
• Breasts (chest) that feel tender and get bigger.
• Nausea and vomiting (called morning sickness, but it can happen day or night).
• Changes in your pelvic organs. These include the Chadwick sign, Goodell sign and Hegar sign. Only a provider can detect the Goodell and Hegar signs. Other changes include increases in vaginal discharge, relaxation in your pelvic joints and a growing belly.
• Changes in your skin. Parts of your skin may darken or you may notice streaks in your skin.

Both at-home pregnancy tests and the pregnancy test you take in your provider’s office usually produce reliable results. You’ll know with certainty that you’re pregnant when your provider detects a fetal heartbeat or sees the fetus on an ultrasound.

What conditions can be mistaken for the Chadwick sign?

Bluish discoloration of your cervix doesn’t always mean pregnancy. Other conditions that can cause your cervix to appear blue include:

• Cervical endometriosis. With endometriosis, tissue similar to the tissue lining your uterus grows outside of it. Endometrial tissue on your cervix may appear blue-colored to a provider examining you. It may cause symptoms like pelvic pain and vaginal discharge. While endometriosis is a common gynecological condition, cervical endometriosis is rare.
• Adenomyosis. Adenomyosis involves your uterine lining growing into the wall of your uterus. It can affect the appearance of your cervix if the uterine lining grows there.
• False pregnancy (pseudocyesis). Pseudocyesis is when a person believes they’re pregnant even when they’re not. The belief can cause changes in your body that cause pregnancy symptoms, including the Chadwick sign.

When should I see a healthcare provider?

Schedule a visit with a healthcare provider if you have pregnancy symptoms, including blue discoloration in your genitals. They may perform a physical exam or pregnancy test to check for other signs of pregnancy.

If the blue color isn’t related to pregnancy, they can explore other factors that may be causing the change.