DIFFERENT CAUSES OF FEMALE INFERTILITY
According to the National Survey of Family Growth, CDC (2006 – 2010), approximately 1 in every 8 couples experiences difficulty in getting pregnant. It is reported that around a third of the infertility cases are due to female factors, another one-third is attributable to the male partner, and the remaining cases are either unexplained or due to a combination of factors.
The underlying causes of female infertility may be traced back to the following five areas:
1. Ovulation Failure
Through the process of ovulation, a woman releases a mature oocyte or egg every month. The failure to ovulate—also known as anovulation—is one of the most commonly observed cause for female infertility.
Fortunately, the majority of these cases can be successfully treated by administering fertility medications, such as Clomiphene, Human menopausal gonadotropins, or letrozole. Hormonal imbalances, the premature onset of menopause, or abnormal follicles may result in ovulation failure, and Hormonal Imbalances lead to the impaired development of ovarian follicles, and therefore the follicles do not make mature oocytes. For example, polycystic ovary syndrome is associated with reduced FSH and normal or increased LH (ie hormonal imbalances), leading to lack of periods, anovulation and infertility.
Furthermore, hormonal imbalances may be a result of the malfunctioning of the hypothalamus. The hypothalamus is located in the brain, and directs the pituitary glands to release FSH and LH, which in turn helps ovulation. Finally, an impaired pituitary gland due to injury or disease may hinder the optimal production of FSH and LH, resulting in anovulation.
Premature menopause causes the untimely cessation of menstrual cycle in some women. This condition may be genetic in origin.
2. Impaired Fallopian Tubes
The Fallopian tubes connect the ovaries and the uterus. The mature egg released from the ovary travels through the Fallopian tube towards the uterus, waiting for fertilization by incoming sperm.
Approximately a quarter of all infertile women have damaged Fallopian tubes, resulting in partial or complete tubal blockage. Surgical measures, such as microsurgery and laser treatment, can be used to treat tubal diseases. Success rates of tubal surgeries range between 10-25 %. In cases when the tubes cannot be repaired, the tubes may be bypassed through IVF procedures culminating in implantation of a fertilized egg in the uterus.
Causes of tubal defects are highlighted as follows:
- Infections in the Fallopian tubes can be of bacterial or viral origin, and are often sexually transmitted. The resulting inflammation can cause scarring and fluid accumulation, leading to tubal blockage.
- Abdominal diseases, such as appendicitis and colitis, can also result in inflammation, scarring and blockage of the tubes.
- Surgeries in the pelvic or abdominal region can cause adhesions within the Fallopian tubes, leading to tubal blockage.
- Tubal or Ectopic pregnancy causes the fertilized egg to develop within the tube instead of the uterus, leading to serious medical condition. Tubal pregnancy causes damage to the Fallopian tubes, leading to its scarring and blockage.
- Congenital tubal disorders, such as aplasia, hypoplasia, accessory ostia and congenital diverticulae, may also result in female infertility.
3. Endometriosis
Endometriosis is the excessive growth of the uterine lining, also known as the endometrium. Endometriosis affects the uterus, fallopian tubes, ovaries and the abdomen. It is estimated that 5 million US women are affected by endometriosis, leading to reduced fertility. Laparoscopy, or visualization of the uterus, tubes and pelvic cavity, is used to diagnose endometriosis. Symptoms may include very painful periods, painful intercourse, heavy painful menstrual bleeding, urinary urgency, rectal bleeding/pain and premenstrual spotting.
4. Miscellaneous Factors
The following varied factors are also known to result in female infertility:
- Uterine abnormalities, such as fibroid, polyps and adenomyosis, which make the uterus less receptive to accept a pregnancy
- Congenital abnormalities (e.g. septate uterus)
- Lifestyle choices, such as diet and exercise, smoking, alcohol intake and the usage of drugs (e.g. narcotics, anabolic steroids), can impact general reproductive health of a woman as well as influence fetal health.
- Environmental factors, such as harmful toxins, can cause genetic mutations in fetus, lead to birth defects, abortions or infertility. The uncontrolled exposures to lead, radiations, ethylene oxide and dibromochloropropane, are known to impair fertility.
5. Unknown Causes
One of the most common causes of infertility is unexplained infertility. All the tests for causes of infertility are normal. Fortunately those with unexplained infertility have good success with treatment and usually conceive easily with therapy.