Infertility Causes
Infertility is a relatively common condition affecting approximately 10% of couples of reproductive age and the incidence of infertility seems to be increasing.
Infertility Causes
Infertility is a relatively common condition affecting approximately 10% of couples of reproductive age and the incidence of infertility seems to be increasing.
The American Society of Reproductive Medicine (ASRM) defines infertility as the inability to conceive after one year of regular, unprotected intercourse. This time is shortened to six months in women over 35 because of the direct correlation between advancing female age and decreased fertility.
Infertility was once considered a “female” problem. We now know that almost half of all infertile couples will have a male infertility component. This finding means that male infertility must be “ruled out” before female therapy begins. Correcting a condition, such as irregular ovulation, does little good if there are not enough “quality” sperm for fertilization. Ovulatory disorders, endometriosis, blockage of the fallopian tube(s), cervical mucous problems, uterine abnormalities, PCOS, miscarriage, and genetic diseases are all causes of infertility.
1. Ovarian
Increasing female age is perhaps the greatest enemy of fertility. The age at which females are marring has also increased. Unfortunately, the societal clock and biological clock are not always in “sync”. These delays in childbearing are partially responsible for the increased incidence of infertility related to age.
Women in their mid-late thirties should not delay seeing a reproductive endocrinologist/ fertility specialist as fertility can decline very rapidly.
A woman is born with more than enough eggs for her reproductive lifetime. In a normally ovulating female each month one, or more, of these eggs are recruited and develop under the influence of FSH. Usually they more sensitive eggs (to FSH)) are recruited first. Several hundred more start to undergo maturation and then become atretic and “die off” each month. As females age, egg quality declines.
Women differ in the number of eggs that become atretic each month, thus some women use up their egg supply faster than others. As a female ages, the less sensitive eggs remain and require more FSH stimulation in order to undergo final maturation.
The pituitary gland at the base of the brain tries to compensate for this decreased egg sensitivity by increasing the FSH levels. High FSH levels suggest decreased ovarian egg sensitivity and indirectly suggest decreased egg quality.
While female age is directly related to infertility; unfortunately, some women experience menopause at an early age, a condition known as premature ovarian failure. When the ovaries are releasing eggs that have diminished capability to fertilize and develop normally, the condition is termed “diminished ovarian reserve.” The ovaries, and therefore the eggs within them, can also be damaged by cancer, cancer chemotherapy, radiation, severe pelvic infections, or rarely women are born without one or both ovaries.
2. Endometriosis
Endometriosis is a relatively common condition affecting 5-10% of women in the general population causing pelvic pain, severe cramping with menses, painful urination, painful and possibly bloody bowel movements, pain during intercourse (dyspareunia), and infertility. It is estimated that endometriosis is present in 38-50% of all infertile women, and in 70-80% of women with chronic pelvic pain.
Endometriosis can cause damage and blockage of the fallopian tubes, and it can attach to the ovaries and other reproductive organs. Because it is “foreign” to the pelvic cavity, the body can mount an immunologic attack to try and destroy it, thus creating an inflammatory environment in the pelvis.
3. Tubal
Once the eggs are released (ovulated) from the ovarian follicles they must be picked up by the fimbriated end of the fallopian tubes. Tubal blockage, or damage, can be caused by endometriosis, which can attach to, and even penetrate, the fallopian tubes. Severe pelvic infections (pelvic inflammatory disease or PID) can cause serious tubal damage as can scar tissue from previous surgeries.
4. PCOS
PCOS causes elevated androgens (typically thought of as male hormones) which lead to many of the clinical manifestations including increased body hair (hirsutism), menstrual irregularities, and sometimes thinning of the hair on the scalp. In many women, it is these elevated insulin levels that ultimately cause the over production of androgens by the ovary, which leads to ovulatory irregularities and the other symptoms. Chronically elevated insulin levels can also lead to long term health consequences including increased incidence of cardiovascular disease, Type II diabetes (non-insulin dependent), and other conditions. A reproductive endocrinologist, infertility specialist or an experienced gynecologist should manage PCOS patients attempting pregnancy.
The disease is complex and there are many facets that must be considered. For example, patients can have an exaggerated, unpredictable response to FSH fertility drugs for ovulation induction.
5. Cervical Factors Cervical Factors
Cervical factor infertility, or male infertility, results when the sperm cannot “swim through” the cervical mucus or when antisperm antibodies are present. Antibodies result when the body “protects itself” from invading pathogens such as viruses and bacteria. The immune system initially identifies the “invader” and begins to produce antibodies to destroy it upon future exposure. Antisperm antibodies result when the body mistakenly identifies sperm as harmful pathogens. Therefore, an immune reaction ensues to destroy the sperm. Rarely, the male can produce antisperm antibodies to his own sperm, usually because of previous testicular trauma or vasectomy.
6. Uterine
The uterus must be free of large obstructions, such as endometrial polyps and fibroids (leiomyomas), for successful implantation and pregnancy to result, These conditions are often observed on the hysterosalpingogram (HSG), during hysteroscopy or at the time of 3D saline sonogram. Sometimes obstructions can be removed laparoscopically or by using the hysteroscope during outpatient surgery. The uterus must also be normally shaped (triangular) and free of congenital defects such as the “double uterus (uterus didelphys) which has two “horns”, unicornuate uterus (only one half of the normal uterus), uterine septum (muscle growth from the top of the inside of the uterus that protrudes into the cavity) and a bicornuate uterus (heart shaped). Some of these defects such as a uterine septum can be corrected by a skilled reproductive surgeon.
7. Miscarriage
One of the major causes of miscarriage is an abnormal number of chromosomes in the embryo. This condition is known as aneuploidy and increases as women age. Currently preimplantation genetic diagnosis (PGD) technology combined with IVF can screen embryos for aneuploidy. One cause of repetitive miscarriages due to genetic problems in the fetus is the situation where the husband or the wife has a balanced chromosomal translocation. This is found in 3-4% of couples who have had 3 or more miscarriages. Some medical conditions, including PCOS, increase the chances of miscarriage. Pretreatment prior to There may also be uterine abnormalities such as congenital or acquired malformations
8. Unexplained
As the name “unexplained infertility” implies, this condition occurs when no obvious cause(s) for a couple’s infertility can be found. This is much different than stating “there is no cause.” This is perhaps one of the most frustrating “diagnoses” because there is no specific organ system that can be targeted for treatment. However, it is one of the most successfully treated diagnoses.