What is the cervix?

Written by Dr. Specialist Stine Andreassen
Specialist in Gynecology and Obstetrics, PhD in Obstetrics in 2015 and more than 15 years of clinical practice in Obstetrics and Gynecology

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The cervix is the lower part of the uterus that connects the uterus to the vagina. Although relatively small, the cervix plays an important role in menstruation, fertility, pregnancy, and childbirth.

The cervix contains a small opening that allows menstrual blood to leave the uterus and sperm to enter the reproductive tract.

Where is the cervix located?

The cervix sits at the upper end of the vagina and forms the entrance to the uterus. It acts as a passage between the uterus and the vagina and changes throughout the menstrual cycle in response to hormonal fluctuations.

What does the cervix do?

The cervix has several important functions.

• Menstruation: Menstrual blood passes through the cervix before leaving the body through the vagina.

• Fertility: The cervix produces cervical mucus that helps sperm travel toward the uterus during the fertile window.

• Pregnancy: During pregnancy, the cervix remains closed to help protect the developing baby.

• Childbirth: As labour approaches, the cervix softens, shortens, and dilates to allow the baby to pass through the birth canal.

How does the cervix change during the menstrual cycle?

Hormonal changes affect both the position and mucus production of the cervix.

Around ovulation:

• Cervical mucus becomes clearer

• Mucus becomes more slippery and stretchy

• Sperm can move more easily toward the uterus

After ovulation:

• Mucus becomes thicker

• Fertility decreases

Why is the cervix important in cervical screening?

The cervix is where cervical screening tests, including Pap smears and HPV testing, are performed. These tests help identify cervical cell changes before they develop into more serious conditions.

Related resources

• What is a pelvic exam?

• What are cervical cell changes?

• Learn more about menstruation

FAQ – The cervix

• What is the cervix?

  The cervix is the lower part of the uterus that connects the uterus to the vagina.

• Can I feel my cervix?

  Some women can feel their cervix inside the vagina, particularly at certain times during the menstrual cycle.

• Does the cervix change during pregnancy?

  Yes. The cervix undergoes significant changes during pregnancy and labour.

• Why is the cervix screened?

  Cervical screening helps identify HPV infections and abnormal cervical cell changes.