The uterus or womb is a core organ of the female reproductive system. From the very moment the embryo attaches to the lining of the uterus, it is home for the developing baby during the 9 months of pregnancy.
The presence of uterine anomalies and/or diseases can affect the womb by causing female infertility. This type of infertility is known as uterine factor infertility, cervical factor infertility or infertility of uterine origin.
In the worst-case scenario, uterine factor infertility can lead to repeated implantation failure or recurrent miscarriages, causing the woman to be unable to bear an ongoing pregnancy. These women might need to use a gestational carrier to have biological children.
The various sections of this article are assembled in the following table of contents.
The normal uterus
The uterus or womb is a hollow muscular organ of the female reproductive system. It is located in the uterine cavity, particularly between the bladder and rectum.
Before giving birth for the first time, the normal size of the uterus is 8 cm × 5 cm × 3 cm. As for the normal anatomical position, it is anteverted (cervix angles forward) and anteflexed (body is flexed forward).
Anatomically, a normal uterus can be divided into the following major regions:
- It is a pear-shaped region that is composed of 3 layers: perimetrium, myometrium, and endometrium. It is connected to the cervix through the internal orifice, and to the Fallopian tubes through the uterine tubes.
- This muscular anatomical structure is the birth canal, that is, the passage through which babies pass during birth. It is also the pathway of sperm throughout their journey to the egg.
Abnormalities in any part of the womb or its function that affect embryo implantation and development can lead to female infertility of uterine origin.
Uterine anomalies, uterine malformations or Müllerian duct anomalies occur during fetal development, particularly during weeks 8 and 17 of pregnancy.
What follows is a list of the different types of Müllerian duct anomalies that may develop in female fetuses:
- Müllerian agenesis
- The woman is born without a womb as a result of a failure in the development of the female reproductive system at embryo stage. The Fallopian tubes are absent as well, whilst the vagina might be absent or underdeveloped. This anomaly is known as Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome.
- Unicornuate uterus
- The uterus is half its normal size, with a single horn that connects to one Fallopian tube. It can lead to complications during pregnancy and increase the risk of preterm birth.
- Bicornuate uterus
- The woman has a heart-shaped uterus, with two symmetric cavities divided by a septum. Potential complications include miscarriage and preterm delivery.
- Uterus didelphys
- Two independent uterine cavities are observed, with two uterine cavities and, in some cases, two vaginas. It causes recurrent miscarriages.
- Septate or arcuate uterus
- The uterus is divided by a central septum. The longer this septum, the higher the chances of miscarriage.
Some of these anomalies can be treated by a surgical procedure such as hysteroscopy or laparoscopy. For example, they can be used to remove the septum from the uterine cavity.
Recommended for you: Uterine Anomalies – Types, Impact on Fertility & Treatment.
Tumors & abnormal growths
A tumor is caused by an abnormal growth of tissue, which causes a swelling of a part of the body.
Normally, uterine tumors are benign and can be easily removed by surgery. Continue reading to learn more:
Uterine fibroids, also called fibromyomas, leiomyomas or myomas, are tumors that form in the muscular layer of the uterus (myometrium). There exist four types:
- Subserosal fibroids
- They grow just beneath the outer layer of the uterus. Sometimes, enlarged subserosal fibroids may affect nearby organs. They are asymptomatic in almost all cases.
- Intramural fibroids
- They grow within the muscular uterine wall. If they grow larger, they may stretch the womb.
- Submucosal fibroids
- Also known as submucous fibroids, they grow into the endometrial cavity. They are the rarest ones, but when present they may cause severe bleeding. Moreover, this type of fibroids can distort and/or block a woman’s Fallopian tubes.
- Pedunculated fibroids
- They can be either subserosal or submucosal, but only attached to the uterine wall by a peduncle, that is, a stalk-like growth.
As regards their relationship with female infertility, fibroids may lead to certain complications based on their size and the grade of severity, including compression on the Fallopian tubes, implantation failure, recurrent miscarriages, etc.
Uterine fibroids can be removed and the woman is likely to recover her fertility by undergoing a myomectomy (also known as fibroidectomy) to remove the fibroids.
Unfortunately, in the most severe cases, the presence of multiple fibroids larger than the size of the uterus, a hysterectomy (removal of the womb) might be necessary. In such case, pregnancy will be no longer possible.
Uterine or endometrial polyps originate when endometrial tissue grows toward the uterine cavity. It occurs when the endometrial lining doesn’t shed with menstruation, which leads to the growth of polyps. If untreated, polyps can continue growing.
Large uterine polyps can cause bleeding between periods (metrorrhagia), after sexual intercourse or an unusual heavy bleeding during menses (hypermenorrhea). Both metrorrhagia and hypermenorrhea are considered major causes leading women to suffer from anemia.
So, in conclusion, symptoms accompanied by these symptoms should be removed, especially if you are planning to get pregnant, as they can cause infertility.
Since they appear within the uterine cavity, endometrial polyps can prevent embryo implantation or cause miscarriage.
Polyps may also grow towards the cervix or near to that area, in which case they are known as cervical polyps. Less than 5% turn out to be cancerous, though.
The endometrium is the innermost layer of the womb, where embryo implantation takes place. In other words, it is responsible for the start of a new pregnancy in women.
The menstrual cycle determines the status of the endometrium, as its structure and functionality vary according to the levels of estrogens and progesterone in the woman. With the end of each cycle, it sheds in the form of what we know as menstrual flow.
So, this borne in mind, we can say that any type of abnormality in the endometrium that prevents it from being functional, including hormonal imbalances, may lead to infertility issues.
The following conditions are common causes of female infertility due to alterations in the endometrium:
Endometriosis is a chronic (long-lasting) disease of the uterus that causes the endometrial tissue to grow outside the endometrial cavity. It can invade other body parts, including the Fallopian tubes, ovaries, ligaments of the pelvis, bladder, intestines, etc.
In the most severe cases (grade IV endometriosis), implants (clumps of tissue) may fill with blood, in which case they are commonly referred to as chocolate cysts or endometrioma cysts.
About 40 percent of women with endometriosis are childless, too. Endometrioma cysts can appear in the ovary and affect the ovarian reserve (supply of eggs) severely. They affect tubal patency and endometrial receptivity to a large extent as well.
Living with severe or grade IV endometriosis can turn out to be really hard—especially due to severe pain, the most common symptom reported by women with endometriosis. There is only one treatment to stop the growth of endometrial implants, which is birth control. Unfortunately, birth control is incompatible with a pregnancy, hence the fact that these women encounter so many problems to have children.
For this reason, many specialists recommend that women with severe endometriosis turn to alternative options to have children, such as gestational surrogacy. Untreated endometriosis is associated with an uncontrolled growth of implants.
Adenomyosis is a type of endometriosis that occurs strictly in the uterus. In this case, the inner lining of the uterus breaks through the myometrium (muscle wall of the uterus).
The most common symptoms of adenomyosis are heavy bleeding during periods, metrorrhagia, lower back pain, and dyspareunia (painful intercourse).
Moreover, this type of endometriosis can make a woman infertile by causing repeated implantation failure and greater chances of miscarrying.
Women with adenomyosis are likely to need fertility treatment in order to have a baby. In the most severe cases, hysterectomy may be required.
Intrauterine synechiae, scarring or adhesions occurs when scar tissue form around the uterine cavity. As a consequence, they alter its function and appearance.
This uterine condition is known as Asherman’s syndrome and can have an extremely negative impact on female fertility.
Uterine synechiae alter the structure of the endometrial lining, and therefore hinder embryo implantation. Also, if the woman gets pregnant, the uterus may stretch as the fetus grows. This can cause complications during pregnancy and increase the miscarriage rate.
Surgery is the best treatment option to eliminate endometrial adhesions.
Asherman’s syndrome is often due to previous surgery to the endometrium that causes damage to its tissue, including D&C, C-section, myomectomy, etc.
The most severe version of Asherman’s syndrome is known as unstuck Asherman’s or endometrial sclerosis. It leads to a lack of endometrial tissue and therefore to the inability for the woman to get pregnant.
Get more info by clicking the following link: Asherman’s Syndrome – Grading, Symptoms, Causes & Fertility.
How to get pregnant
As explained through this post, the most appropriate treatment to achieve an ongoing pregnancy that leads to the birth of a healthy baby depends on the cause of infertility.
The best-case scenario is when a simple surgical procedure such as hysteroscopy works. In these cases, the woman recovers her ability to get pregnant successfully. For example, this would be the most adequate treatment option in cases of uterine anomalies or uterine myomatosis.
Also, some Assisted Reproductive Technologies (ART) like IVF or egg donation have allowed many women with uterine factor infertility have a baby with success.
Finally, gestational surrogacy can be used as a last resort in the most severe cases. Patients with serious illnesses, including medical contraindications to pregnancy, or even in those born without a womb, can turn out to a surrogate to have a baby.
The regulations governing surrogacy vary by state. In other words, it is not legal in all 50 US states. Some intended parents decide to pursue surrogacy abroad, which is another plausible option. In case you are interested in international surrogacy, click here: International Surrogacy – Laws & Options for Surrogacy Abroad.
Surrogacy is probably the most confusing of all infertility treatments. Transparency is a key value for us when it comes to recommending a clinic or agency for intended parents. You can now use The Calculator to receive a detailed report that will solve any question you may have, and most importantly, to help you avoid potential frauds.
FAQs from users
What is absolute uterine factor infertility?
Absolute uterine factor infertility (AUFI) refers to infertility that is 100% due to conditions that originate in the uterus, either because it is absent (MRKH syndrome or hysterectomy) or because there is an abnormality (anatomic or functional) that prevents embryo implantation or completion of pregnancy.
Can a woman have a baby without a womb?
No, it is not possible in any case. For embryo implantation to occur, a viable uterus has to be present. No uterus equals inability to get pregnant. A woman without a womb should consider using a gestational surrogate to create a family.
Related content: What Is MRKH Syndrome? – Causes, Symptoms & Treatment.
Suggested for you
If you suffer from a serious uterine disease or anomaly, or if you don’t have a uterus, you may have considered surrogacy as an option to start a family. Read this post to learn how it is regulated: Surrogacy in the USA – Is It Legal in All 50 States?
To read about other diseases that can prevent a woman from completing a pregnancy to term, click here: Medical Contraindications to Pregnancy – When to Use a Surrogate.