To analyze the causes of female infertility, the patient should undergo some tests. There are several factors that can make difficulty of getting pregnant for a woman. Among the most common are:
- Hormonal disorders that prevent or hinder ovum growth and release (ovulation);
- Polycystic Ovarian Syndrome;
- Problems in the fallopian tubes caused by infections or surgeries;
- Tubal ligation;
- Cervical mucus that prevents the passage of sperma;
- Infection in the cervix;
According to traditional medical knowledge, ovum production occurs along with fetus formation. Women would already be born with the eggs to be released throughout life with each menstruation. This way older the patient is, older her egg would be, making it difficult for pregnancy to occur. Recent studies indicate, however, the likelihood that adult women will also produce new eggs, which could increase effectiveness of female infertility treatments.
Problems in the uterus are the most common. Some hormonal imbalances that occur during the woman's fertile period can make cervical mucus thicker, making it difficult or impossible for sperm to pass. Hormonal imbalances are also recurrent after age 35. Endometriosis or leiomyomas can also make pregnancy difficult.
Smoking also affects female fertility. Smoking may interfere with fertilization, implantation of the conceived ovum, or subclinical loss after implantation. Thus, a woman who wishes to become pregnant should stop smoking for at least two months before attempting to become pregnant. According to studies, woman fertility is more affected by smoking than man, although this also may face negative consequences of smoking in trying to be a father.
To detect infertility cause, the couple should first seek the gynecologist and report the problems presented. After the diagnosis of female infertility, complementary tests will be requested to identify the causes and possible treatments.
Ovarian and Ovary Causes
One of the diseases that occurs with lack of ovulation is the so-called polycystic ovary syndrome (or chronic anovulation syndrome) in which the patient has irregular uterine bleeding, usually every 2 or 3 months and the ultrasound examination shows a presence of innumerable ovarian follicles (pockets of fluid that may each ovum contain) often located at the periphery of the ovary. As these patients may have increased male hormones (androgens) they sometimes have increased hair and, more rarely, hair loss. They may also present obesity and difficulty in assimilating carbohydrates , due to insufficient insulin action.
In premature ovarian failure (or early menopause), the ovaries stop maturing the eggs, so that ovulation ceases. In general, patients have no menstrual cycle and menopause-like symptoms (especially hot flushes or hot flashes). The causes of disease are manifold: radiation, chemotherapy, genetic syndromes, ovarian infections, autoimmune diseases and others.
Excess secretion of prolactin (hyperprolactinemia) alters control ovaries mechanisms and induces several failures in menstrual cycle, which can culminate in a lack of menstrual cycle and ovulation. Similarly, diseases that affect the thyroid (especially hypothyroidism) make it possible to produce similar changes.
Another important cause in egg reduction is the age. With aging a woman progressively produces fewer and lower quality eggs. This process basically starts at age 37.
Tubal and endocervical canal causes
Tubal obstruction prevents capture and egg transport, so that there is no fertilization possibility by a spermatozoid. Eventually, tubas dilate greatly, which is visible in specialized examination. There are two main causes of this disease: endometriosis and pelvic infections.
In endometriosis fragments of the endometrium penetrate tubas (retrograde menses) and produce inflammation, which ultimately changes tube function, which is gametes transport. Sometimes, endometriosis extends to ovaries too, damaging the formation of follicles. There are patients who have more severe form of endometriosis, which begins when they begin to menstruate: in general, they are younger patients and in that case, the risk for infertility is higher because of more aggressive potential of the disease. A very typical symptom of this disease is pain during sexual intercourse and very strong menstrual cramps.
Pelvic infections, which in many cases are asymptomatic, are caused by microorganisms that can migrate from the vagina to uterus and tubas. Like endometriosis it produces inflammation whose healing promotes scarring that ultimately changes tubes functioning. Greater the frequency of gynecological infections greater is the chance of tubal involvement.
Cervical mucus secreted by cervix must be penetrated by spermatozoid on its way to fertilize the egg. Its secretion depends on hormones produced by the ovarian follicles (estradiol). Therefore, changes in ovulation may, indirectly, hinder the production of mucus. Other conditions that alter the secretion of this mucus and contribute to infertility are cauterizations of the cervix and surgeries for cancer of the cervix.
Causes of Fertilization
Fertilization depends on sperm and egg vigor. First, the spermatozoid must pierce egg outer layer and penetrate inside of that cell. On that occasion, by means of a process that involves two gametes chromosomes, the egg or zygote is formed that initiates a cellular division and will form, in the future, the embryo. If there are defects in the chromosomes or other structures that regulate the fusion of the two gametes, there will be no fertilization.
Causes associated with implantation of the embryo
Implantation is the penetration of the embryo into the lining of the uterine cavity, called the endometrium. This coating is prepared to receive the embryo formed after ovulation and fertilization. Female hormones (estrogen and progesterone) are responsible for preparing the endometrium during the menstrual cycle. Therefore, hormonal failures may produce an endometrium that is unsuitable for implantation. The conditions that reduce the probability of implantation are:
Inadequate development of the endometrium: even with normal hormones, it can react exaggeratedly and produce a non-favorable condition for pregnancy: hyperplasia. Sometimes, this hyperplasia is localized, forming a polyp. When the endometrium does not grow or grow very little, we speak of hypoplasia, also negative for implantation.
Endometrial infections (endometritis), caused by sexually transmitted diseases or by manipulation of the endometrial cavity (in dressings, for example).
Uterine synechiae: they are like scars inside the uterine cavity, coming from infections or curettes. In addition to making implantation difficult, they cause abortion.
Uterine malformations: although some changes of this type do not completely prevent pregnancy, they can make it difficult to obtain and cause abortion.
Fibroids: although they are more closely linked to abortion procedures, it is believed that if large and located immediately below the cavity, invading it, they can also impair the implantation of the embryo.