Hegar’s sign, also known as Hegar’s sign of pregnancy, is a sign used to confirm pregnancy, typically occurring between the sixth and eighth weeks of gestation, and is also used to estimate gestational age. It is characterized by the softening of the lower uterine segment and cervical dilatation in response to pressure from the growing fetus. Hegar’s Sign was first described in 1879 by German gynecologist Ernst Heinrich Georg August Ludwig Hegar. It is named after him.

The exact cause of Hegar’s sign is unknown, but it is believed to be caused by changes in the levels of hormones during pregnancy. There are no known risk factors associated with Hegar’s sign. However, some complications that have been associated with it include preterm labor and placental abruption. 

Hegar’s Sign is a physical finding during a pelvic examination. The examiner palpates (feels with their fingers) the lower part of the uterus through the vagina and cervix. Normally, this area feels firm like the tip of your nose. With Hegar’s sign, the lower uterine segment  softens  and the cervix starts to dilate (open) in response to pressure from the growing fetus.

Importance

Hegar’s sign can be useful in two ways: 

1) To help confirm that a woman is pregnant, especially if she has a history of irregular periods or has been recently sexually active; 

2) To help estimate how far along (gestational age) a pregnant woman is, based on when Hegar’s sign is first detected. However, it is important to note that Hegar’s sign is not always an accurate predictor of gestational age and should not be used as the sole method for estimating due date.

Disambiguation

There are some other terms that are often confused with or used interchangeably with Hegar’s sign:

Chadwick’s sign: Chadwick’s sign refers to overall darkening/bluish discoloration of the vagina and cervix, which can occur in early pregnancy due to increased blood flow to these areas. Unlike Hegar’s sign, Chadwick’s sign is not specific to pregnancy and can also be seen in non-pregnant women. 

Goodell’s sign: Goodell’s sign refers to softening of the cervix, which can also occur in early pregnancy as a result of increased blood flow and hormonal changes. Unlike Hegar’s sign, Goodell’s sign does not necessarily involve dilatation (opening) of the cervix.

Other Related Terms

There are a few terms that are closely associated with Hegar’s sign. These include cervical effacement, cervical dilation, and uterine prolapse.

This image shows how often the term ‘Hegar’s Sign’ is used in relation to other, similar birth terms:

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