Causes Of Female Infertility
1. Hormone Imbalance
- Poly Cystic Ovarian Syndrome
- Premature Menopause
2. Physical Abnormalities
- Fallopian Tubes
- Uterine Abnormalities
- Cervical incompetence
- Immune System
3. Uterine Factors
1. HORMONAL IMBALANCE
Female infertility is often caused by a woman’s inability to ovulate or release an egg. Failure to ovulate is usually rooted in hormonal problems. Fortunately hormonal imbalances are not hard to detect and treatments are straightforward and relatively effective.
In many infertility cases, a woman may be producing too little of one hormone or too much of another. Such is the case with the conditions listed here.
Hormonal imbalances can sometimes be traced back to the primary glands (hypothalamus, thyroid and pituitary) that produce reproductive hormones. The hypothalamus, pituitary and ovaries send signals back and forth during the reproductive process that cause changes in hormone production.
- Hypothalamus: This gland can be affected by stress, birth control pills, disease and some medications.
- Thyroid: An under-active thyroid gland causes hypothyroidism and can be characterized by excessive levels of the hormone prolactin, which interferes with ovulation.
- Pituitary: Microscopic tumors (prolactinomas) on the pituitary gland can secrete the hormone prolactin, which interferes with ovulation.
Ovulation is one of the leading causes of female infertility, in about 25% of cases. Some women ovulate irregularly or do not ovulate at all (this is called anovulation). When women have problems with ovulation it’s usually because they have hormonal imbalances such as too much prolactin (a milk-producing hormone that suppresses ovulation) or too many androgens.
Androgens, or male sex hormones, the most important of which is testosterone, promote the development of male sex characteristics. Both males and females have the same starting products of androgens. Androgen levels rise continuously between the ages of seven and thirteen in puberty, prompting the appearance of axillary and pubic hair. They are also responsible for sex drive, and may be converted to estrogen after menopause when ovarian estrogens are no longer produced. An imbalance can cause the shift for women to have too many androgens or men to have too little.
Polycystic ovarian syndrome (PCOS)
Polycystic Ovarian Syndrome (PCOS), is a condition in which hormone imbalances interfere with ovulation. The adrenal glands and ovaries produce excessive amounts of male hormone, which leads to an abnormally high production of luteinizing hormone (LH) and an abnormally low production of follicle-stimulating hormone (FSH). As a result, the ovary fills with cysts of immature follicles that are unable to generate eggs.
Women with this condition may experience:
- Irregular periods
- Enlarged ovaries
- Excessive facial and body hair
- Oily skin
Why do women with Polycystic Ovarian Syndrome (PCOS) have trouble with their menstrual cycle?
The ovaries are two small organs, one on each side of a woman’s uterus. A woman’s ovaries have follicles, which are tiny sacs filled with liquid that hold the eggs. These sacs are also called cysts. Each month about 20 eggs start to mature, but usually only one becomes dominant. As the one egg grows, the follicle accumulates fluid in it. When that egg matures, the follicle breaks open to release the egg so it can travel through the fallopian tube for fertilization. When the single egg leaves the follicle, ovulation takes place.
In women with PCOS, the ovary doesn’t make all of the hormones it needs for any of the eggs to fully mature. They may start to grow and accumulate fluid. But no one egg becomes large enough. Instead, some may remain as cysts. Since no egg matures or is released, ovulation does not occur and the hormone progesterone is not made. Without progesterone, a woman’s menstrual cycle is irregular or absent. Also, the cysts produce male hormones, which continue to prevent ovulation
Women under 40 years of age whose ovaries are not producing sufficient hormones to sustain ovulation and menstruation are deemed prematurely menopausal. Premature menopause, also known as premature ovarian failure (POF), occurs in 1 to 4% of women and occurs when a woman has prematurely depleted her supply of eggs.
Abnormal cervical mucous
Normal cervical secretions are a vital component to successful impregnation. Many women notice a change in the consistency of their cervical mucus throughout the menstrual cycle. Cervical mucous is thin and watery around the time of ovulation, making it easy for sperm to enter the uterus. Abnormal cervical mucous is a rare condition that involves at least one of the following:
The cervical mucous is too thick for sperm to swim through even during ovulation.
The cervical glands do not produce enough mucous.
In some cases, surgery or infection can damage the glands that produce cervical secretions, which can ultimately cause mucous abnormalities.
2. PHYSICAL ABNORMALITIES
Endometriosis is a benign disease defined by the presence of ectopic (outside the uterus) endometrial tissue and stroma that can be associated with pelvic pain and infertility. Endometriosis exhibits a broad spectrum of clinical manifestations, is prone to progression and recurrence, and often presents difficult clinical management problems for women and their clinicians. Endometriosis is a major cause of infertility and may be present with no symptoms. Some studies indicate that endometriosis decreases pregnancy rates even though there may be little visible organ damage.
Endometriosis lesions can be found anywhere in the pelvic cavity: on the ovaries, the fallopian tubes, and on the pelvic sidewall. Other common sites include the uterosacral ligaments, the cul-de-sac, the Pouch of Douglas, and in the rectal-vaginal septum.
In addition, it can be found in caesarian-section scars, laparoscopy or laparotomy scars, and on the bladder, bowel, intestines, colon, appendix, and rectum.
In rare cases, endometriosis has been found inside the vagina, inside the bladder, on the skin, even in the lung, spine, and brain.
The most common symptom of endometriosis is pelvic pain. The pain often correlates to the menstrual cycle, but a woman with endometriosis may also experience pain that doesn’t correlate to her cycle. For many women, the pain of endometriosis is so severe and debilitating that it impacts their lives in significant ways.
Endometriosis can also cause scar tissue and adhesions to develop that can distort a woman’s internal anatomy. In advanced stages, internal organs may fuse together, causing a condition known as a “frozen pelvis.”
The infertility associated with endometriosis has been attributed to three primary mechanisms: distorted adnexal anatomy that inhibits or prevents ovum capture after ovulation, interference with oocyte development or early embryogenesis, and reduced endometrial receptivity.
Symptoms of endometriosis
The most common symptom of endometriosis is pelvic pain. The pain often correlates to the menstrual cycle, however a woman with endometriosis may also experience pain at other times during her monthly cycle.
For many women, but not everyone, the pain of endometriosis can unfortunately be so severe and debilitating that it impacts on her life significant ways.
Pain may be felt:
- before/during/after menstruation
- during ovulation
- in the bowel during menstruation
- when passing urine
- during or after sexual intercourse
- in the lower back region
Other symptoms may include:
- diarrhoea or constipation (in particular in connection with menstruation)
- abdominal bloating (again, in connection with menstruation)
- heavy or irregular bleeding
The other well known symptom associated with endometriosis is infertility. It is estimated that 30-40% of women with endometriosis are subfertile.
The fallopian tubes are the channels between the uterus and the ovaries. Sometimes these tubes are to found to be blocked or at least one is blocked or there is scarring or other damage to the tube.
Infections, endometriosis, scar tissue, adhesions, and damaged tube ends (fimbria) can result in blocked or otherwise abnormal fallopian tubes. Even if you ovulate regularly, blocked tubes make pregnancy next to impossible, since your egg can’t get to your uterus, and sperm can’t get to your egg.
Possible solutions: The main treatment is usually IVF. However, if the blockage is found to be limited to a small area it might be possible to clear it by laparoscopy or open tubal surgery to remove the blocked portion. Infections such as chlamydia tend to damage the whole length of the tube and are less amenable to surgery. A laparoscopy is usually carried out to determine which is the most appropriate treatment for you.
Abnormalities of the uterus are a relatively uncommon cause of infertility but should always be considered. The anatomic uterine abnormalities that may adversely affect fertility include congenital malformations, leiomyomas (fibroids), intrauterine adhesions (scarring), and endometrial polyps. These same abnormalities can also adversely affect pregnancy outcome (recurrent pregnancy loss).
- Congenital Uterine Malformations
- Uterine Leiomyomas (fibroids)
- Intra-uterine adhesions (Ashermans Syndrome)
- Endometrial polyps
Congenital Uterine Malformations
Developmental uterine anomalies have long been associated with pregnancy loss and obstetric complications, but the ability to conceive is generally not affected.
When discovered during evaluation for infertility, anomalies cannot, therefore, be regarded as the likely cause or even as an important contributing cause of infertility but only as another obstacle that must be considered when choosing from the range of treatment options once evaluation is completed. For example, treatments that are associated with substantial risk for multi-fetal gestations ( superovulation with IUI, IVF ) present even greater risks to women with uterine malformations.
There are quite a few different kinds of problems of the uterus:
A bicornuate uterus (a womb with two ‘horns’) is the most common. Instead of the womb being pear-shaped, it is shaped like a heart, with a deep indentation at the top. This means that the baby has less space to grow than in a normally shaped womb.
A unicornuate uterus (a womb with one ‘horn’) happens when the tissue that forms the womb does not develop properly. This is a very rare condition. A unicornuate uterus is just half the size of a normal womb and the woman has only one fallopian tube. However, she usually has two ovaries.
A double uterus, technically called a “uterus didelphys”, is when the uterus has two inner cavities. Each cavity may lead to its own cervix and vagina, so the woman has two cervixes and two vaginas. Again, this is very rare.
A septate uterus is where the inside of the uterus is divided by a wall (septum). The septum may extend only part way into the uterus or it may reach as far as the cervix.
Normally, the uterus leans forwards over the top of the bladder. Doctors call this position “anteverted” and “anteflexed”. Some women have a tilted uterus (which may also be described as “backward”, “retroflexed”, “retroverted” or “tipped”) which leans away from the bladder rather than over it.
Among all congenital uterine abnormalities, the septate uterus is both the most common and the most highly associated with reproductive failure and obstetrical complications, including first and second trimester miscarriage, preterm delivery, fetal malpresentation, intrauterine growth retardation, and infertility.
A tilted uterus does not make a woman less fertile. Women with a unicornuate uterus may have difficulties conceiving, because they have only one fallopian tube. However, pregnancy in women with this condition is far from unknown. In general, uterine abnormalities do not prevent a woman from getting pregnant, but they may make it more difficult for her to carry a baby for the full nine months of pregnancy.
Uterine Leiomyomas ( Fibroids )
Available evidence indicates that pregnancy and implantation rates are significantly lower in women with submucous myomas but not in those with subserosal or intramural myomas that do not encroach on or clearly distort the endometrial cavity, at least when they are relatively modest in size ( less than 5 – 7 cm ).
Judgments concerning the indications for surgical intervention in infertile women with myomas in many ways parallel those in women with congenital uterine malformations. Like septate uteri, submucous myomas are associated with a decreased probability for successful pregnancy and are most often amenable to that has relatively low morbidity and avoids the risks and consequences of abdominal uterine surgery. The management of uterine myomas in infertile women must be highly individualized.
Consideration is given to the relative risks, benefits, and consequences of different surgical treatments, as well as age, ovarian reserve, reproductive history, duration of infertility, other infertility factors and the treatment they require, plus the size, number, and location of myomas.
Intrauterine Adhesions ( Asherman’s Syndrome )
Asherman’s Syndrome is an acquired uterine disease, characterized by the formation of adhesions (scar tissue) in the uterus. In many cases the front and back walls of the uterus stick to one another. In other cases, adhesions only occur in a small portion of the uterus. The extent of the adhesions defines whether the case is mild, moderate or severe.
Most patients with Asherman’s have scanty or absent periods (amenorrhea) but some have normal periods. Some patients have no periods but feel pain at the time each month that their period would normally arrive. This pain may indicate that menstruation is occuring but the blood cannot exit the uterus because the cervix is blocked by adhesions. Other symptoms include recurrent pregnancy loss and placenta accreta.
Most commonly, intrauterine adhesions occur after a D&C (dilatation and curettage) that was performed because of a miscarriage or because of retained placenta with or without hemorrhage after a delivery. Adhesions sometimes also occur in other situations, such as after an elective abortion, after a ceasarean section, after uterine surgery (for example, after surgery to remove fibroids), or as a result of pelvic tuberculosis. The more D&Cs done after a delivery (and especially D&Cs done in the second to fourth week after delivery), the higher is the likeliness of developing adhesions
Chronic inflammatory or infectious insults, notably genital tuberculosis, also can result in intrauterine adhesions. Hysteroscopy is the method of choice for treatment of intrauterine adhesions and is safer and more effective than blind curettage.
The overall prevalence of polyps in infertile women is approximately 3% – 5%. The prevalence is higher in women with other symptoms (abnormal bleeding) and may also be higher in those with endometriosis. Polyps can be identified by HSG or transvaginal ultrasound.