Cervical factor: female sterility due to cervical abnormalities

By (gynecologist), (embryologist) and (psychologist).
Last Update: 03/07/2016

The cervix is the lower part of the uterus, which connects the vagina to the uterine cavity.

Its main function is to act as an initial barrier against the entry of spermatozoa into the female reproductive tract during sexual intercourse.

The cervix is also the outflow channel for blood during menstruation.

Infertility of cervical origin.

The cervix is the canal that connects the vagina to the uterus. It measures approximately 3 cm and has two important functions related to fertility:

  • It is the place where sperm cells enter on their way to fertilize the egg
  • It is the tube through which the baby is born after 40 weeks of gestation during vaginal delivery.

Any alteration in the cervix may imply a sterility problem. However, only 5-10% of couples with difficulty in achieving pregnancy have infertility caused by cervical factor.

In addition to the structure of the cervix itself, inside the cervix, we find a key component for female fertility: cervical mucus. We will now discuss their functions and features.

Cervical mucus

Cervical mucus or discharge is a mucous substance released by the cervix, whose appearance and consistency vary depending on the time of the woman's menstrual cycle due to the effect of sex hormones.

The main functions of cervical mucus are as follows:

  • Change its consistency from thicker to more watery to allow the passage of spermatozoa at the time of ovulation
  • Protect sperm from the vaginal environment
  • Select the most suitable spermatozoa for fertilization, leaving behind those that are defective and with impaired motility
  • Semen capacitation: nutrition of spermatozoa and separation of sperm components

In short, cervical mucus acts as the first filter for sperm to enter the uterus.

In the days close to ovulation, the cervical mucus is liquid and abundant due to the influence of estrogens. After the fertile days, this mucus becomes thin, viscous, and thick as the release of progesterone begins.

If you want to learn more about cervical discharge and how it indicates a woman's fertile period, you can continue reading in the following post: What does the cervical mucus look like during the fertile period?

Cervical alterations

Cervical alterations that can lead to sterility due to a cervical factor can be differentiated into anatomical or functional.

In both cases, the correct migration of spermatozoa to the uterus and fallopian tubes is affected.

Anatomical alterations

As a consequence of these pathologies, an obstruction of the cervix usually occurs. These are discussed below:

Developmental abnormalities
occur from birth as a result of defects in the fusion of the Müllerian ducts. For example, cervical duplication, cervical agenesis or cervical hypoplasia.
such as polyps, fibroids or cysts. They are usually benign in origin and can be removed by surgery. The most serious case would be cervical cancer, which can be caused by human papillomavirus (HPV) infection.
can be produced by surgery or appear occasionally. For example, tears, perforations, fistulas or incontinence of the internal and external orifices.
acute or chronic inflammation of the cervix. It is usually caused by microbial infections such as chlamydia, Trichomonas vaginalis, candida or mycoplasma.

There are other alterations at the cervix level. However, its impact on women's fertility is minimal or with a very low incidence.

Functional alterations

They refer to the variation in the characteristics of cervical mucus, such as its consistency, quantity, acidity, etc.

Any alteration in the cervical flow can prevent sperm from entering the uterine cavity and, therefore, cause infertility.

The causes that provoke alterations in cervical mucus are the following:

Insufficient estrogen release
if during the follicular phase of the menstrual cycle an inadequate amount of estrogen is not produced by the ovary, the cervical mucus becomes thicker and does not allow the passage of sperm when ovulation takes place.
clomiphene citrate has an anti-estrogenic action on the ovaries.
the invasion of microorganisms into the cervix also causes an alteration of the mucus, in addition to inflammation of the cervical walls.
Antispermatozoa antibodies
its presence in cervical mucus is also a consequence of infection.

If you want to know in more detail the role of estrogens in the female menstrual cycle, we recommend you to read the following post: Estrogens.

Diagnostic tests

Normally, cervical factor studies are not routinely performed in women with infertility problems. However, if the woman has symptoms or suspects that she may have some alteration at the level of the cervix, it is possible to perform the following tests:

Postcoital test (PCT or Sims-Huhner test)
the presence or absence of motile spermatozoa in the cervical mucus after sexual intercourse is studied.
Microbiological cultures
to confirm if there is any bacterial infection.
Cervical patency test
a cannula is inserted to check if it passes easily or if there is any obstruction.
In vitro immunological test
the mucus-semen interaction, its characteristics, the ability of the sperm to pass through the cervical mucus and the presence of antisperm antibodies in both fluids are evaluated.
the inside of the cervix is observed thanks to the introduction of a camera.

Prior to these tests, the gynecologist performs a physical examination and an ultrasound on all women who come for a check-up. In some cases, some cervical abnormalities can already be detected in this first examination.


The treatment of cervical factors depends on the specific cause that is causing infertility. In the following, we will discuss the most frequent treatments nowadays:


The use of antibiotic medications is indicated in cases of vaginal infections or acute cervicitis.

First of all, it is necessary to identify the microorganism causing the infection in order to select the appropriate type of antibiotic.

In the case of chronic cervicitis, the option of combining antibiotic treatment and surgery should be considered.

Estrogen therapy

In cases of insufficient or inadequate cervical mucus, administration of exogenous estrogens may result in an improvement in the quantity and quality of cervical mucus.

Estrogens should be taken during the first phase of the menstrual cycle, from day 5 to approximately day 13.

Surgical intervention

It is the appropriate method when there is a tumor that must be removed, as well as when there are anomalies in the development of the cervix.

Trauma to the cervix should also be surgically repaired.

Finally, cauterization of the cervix is the most appropriate method to eliminate malignant cells or infectious agents. For more information, you can continue reading the following article: Cauterization of the cervix.

Artificial insemination (AI)

This assisted reproduction treatment is suitable for couples or women with cervical factors who wish to have a child.

Artificial insemination is a very simple procedure that consists of introducing previously capacitated sperm into the uterine cavity with an insemination cannula.
This avoids the barrier formed by the cervix and increases the chances of pregnancy.

Did you know that we can help you to choose a fertility clinic for your IUI cycle? All you have to do is get your Fertility Report now. It is an easy-to-use tool that is capable of filtering the best clinics and tailor an individual report exclusively for you with useful tips that will help you make a well informed decision.

FAQs from users

Can alterations in the cervical mucus lead to female infertility?

By Óscar Oviedo Moreno M.D. (gynecologist).

Yes, alterations in the cervical mucus can are a common cause of female infertility. The cervical mucus is a secretion produced before ovulation and it disappears after the woman ovulates. It has a sticky texture, and its mission is to pave the way for sperms toward the tubes. It is, in fact, a good indicator of female fertility.

What is the cause of chronic inflammation of the cervix?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

Inflammation of the cervix, also called cervicitis, can be acute or chronic. Although the causes of both types can be highly variable, they are usually due to infection by microorganisms such as for example, chlamydia, trichomoniasis, gonorrhea, herpes virus, and human papillomavirus.

Cervicitis can prevent pregnancy and cause infertility, as well as other discomforts such as leucorrhea, dysmenorrhea, pain during sexual intercourse, etc.

How is it possible to make an early detection of cervical alterations?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

Normally, alterations affecting the cervix are detected in routine gynecological examination with ultrasound or cytology. If it is not very clear or there is a cause of infertility that could be due to the cervical factor, it is possible to do further tests such as those explained in this article.

What is the difference between an endometrial polyp and an endocervical polyp?

By Zaira Salvador B.Sc., M.Sc. (embryologist).

Endometrial polyps are those that appear inside the uterine cavity. On the other hand, there are also cervical polyps, those that form at the edge of the cervix, and endocervical polyps, those that are inside the cervical canal.

Polyps that form in the cervix can grow to protrude into the vagina.

Cervicitis is a cause of female infertility due to a cervical factor. If you want to know in detail what this pathology consists of, we recommend you to read the following post: Cervicitis.

Artificial insemination is the appropriate technique to achieve pregnancy when there is sterility due to a cervical factor. You can find more information and a step-by-step process in the following article: Artificial insemination.

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Authors and contributors

 Óscar Oviedo Moreno
Óscar Oviedo Moreno
Bachelor's Degree in Medicine & Surgery from the University of Caldas (Colombia). Specialist in Internal Medicine by the Pontificia Universidad Javeriana of Bogotá. Degree standardized in Spain in 2003. Specialist in Gynecology & Obstetrics from the Complutense University of Madrid, with residence at Hospital Clínico Universitario San Carlos de Madrid. Expert in Reproductive Medicine and Certification in Obstetric-Gynecologic Ultrasound (levels I, II and III). More information about Óscar Oviedo Moreno
License: 282858310
 Zaira Salvador
Zaira Salvador
B.Sc., M.Sc.
Bachelor's Degree in Biotechnology from the Technical University of Valencia (UPV). Biotechnology Degree from the National University of Ireland en Galway (NUIG) and embryologist specializing in Assisted Reproduction, with a Master's Degree in Biotechnology of Human Reproduction from the University of Valencia (UV) and the Valencian Infertility Institute (IVI) More information about Zaira Salvador
License: 3185-CV
Adapted into english by:
 Cristina  Algarra Goosman
Cristina Algarra Goosman
B.Sc., M.Sc.
Graduated in Psychology by the University of Valencia (UV) and specialized in Clinical Psychology by the European University Center and specific training in Infertility: Legal, Medical and Psychosocial Aspects by University of Valencia (UV) and ADEIT.
More information about Cristina Algarra Goosman
Member number: CV16874

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