Infertility, Female

Infertility affects about 10% to 15% of all couples in the United States. About 40% to 50% of all infertility is attributed to the female. After extensive investigation and treatment, about 50% of these infertile couples achieve pregnancy. Of the 50% who don't, 10% have no pathologic basis for infertility; the prognosis in this group becomes extremely poor if pregnancy isn't achieved after 3 years.

Causes

The causes of female infertility may be functional, anatomic, or psychological.

Functional causes

Complex hormonal interactions determine the normal function of the female reproductive tract and require an intact hypothalamic-pituitary-ovarian axis, a system that stimulates and regulates the production of hormones necessary for normal sexual development and function.

Any defect or malfunction of this system axis can cause infertility due to insufficient gonadotropin secretions (both luteinizing hormone [LH] and folliclestimulating hormone). The ovary controls and is controlled by the hypothalamus through a system of negative and positive feedback mediated by estrogenproduction. Insufficient gonadotropin levels may result from infections, tumors, or neurologic disease of the hypothalamus or pituitary gland. Hypothyroidism also impairs fertility.

Anatomic causes

The anatomic causes of female infertility include the following:

• Ovarian factors related to anovulation and oligo-ovulation (infrequent ovulation) are a major cause of infertility. Presumptive signs of ovulation include regular menses, cyclic changes reflected in basal body temperature readings, postovulatory progesterone levels, and endometrial changes due to the presence of progesterone. The absence of presumptive signs suggests anovulation.

Ovarian failure, in which no ova are produced by the ovaries, may result from ovarian dysgenesis or premature menopause. Amenorrhea is often associated with ovarian failure. Oligo-ovulation may be due to a mild hormonal imbalance in gonadotropin production and regulation and may be caused by polycystic disease of the ovary or abnormalities in the adrenal or thyroid gland that adversely affect hypothalamic-pituitary functioning.

• Uterine abnormalities may include a congenitally absent uterus, bicornuate or double uterus, leiomyomas, or Asherman's syndrome, in which the anterior and posterior uterine walls adhere because of scar tissue formation.
• Tubal and peritoneal factors are due to faulty tubal transport mechanisms and unfavorable environmental influences that affect the sperm, ova, or recently fertilized ovum. Tubal loss or impairment may occur secondary to ectopic pregnancy.

Frequently, tubal and peritoneal factors result from anatomic abnormalities: bilateral occlusion of the tubes due to salpingitis (resulting from gonorrhea, tuberculosis, or puerperal sepsis),peritubal adhesions (resulting from endometriosis, pelvic inflammatory disease [PID], use of an intrauterine device for contraception, diverticulosis, or childhood rupture of the appendix), and uterotubal obstruction due to tubal spasm.

• Cervical factors may include a malfunctioning cervix that produces deficient or excessively viscous mucus and is impervious to sperm, preventing entry into the uterus. The cervix may also be stenotic or dilated.

Psychological problems

Signs and symptoms

The inability to achieve pregnancy after having regular intercourse without contraception for at least 1 year suggests infertility.

Diagnosis

nvestigating suspected infertility requires a number of tests for both the woman and her partner. Tests for the woman may include:

• Blood tests - to check for the presence of ovulation hormones.
• Laparoscopy - a 'keyhole' surgical procedure in which an instrument is inserted though a small incision in the abdomen so that the reproductive organs can be examined.
• Ultrasound tests - to check for the presence of fibroids.

Treatment

Effective treatment depends on identifying the underlying abnormality.

Functional infertility

In hyperactivity or hypoactivity of the adrenal or thyroid gland, hormone therapy is necessary; a progesterone deficiency requires progesterone replacement. Anovulation necessitates treatment with clomiphene, human menopausal gonadotropins, or human chorionic gonadotropin; ovulation usually occurs several days after such treatment.

If mucus production decreases (an adverse effect of clomiphene), small doses of estrogen to improve the quality of cervical mucus may be given concomitantly.

Anatomic infertility

Surgical restoration may correct certain anatomic causes of infertility, such as fallopian tube obstruction. Surgery may also be necessary to remove tumors located in or near the hypothalamus or pituitary gland. Endometriosis requires drug therapy (danazol or medroxypro gesterone, or non cyclic administration of oral contraceptives), surgical removal of areas of endometriosis, or both.

Other options, often controversial and involving emotional and financial cost, include surrogate mothering, frozen embryos, in vitro fertilization, and artificial insemination.

Prevention

Most types of infertility cannot be prevented. All women should increase folic acid intake (found in green leafy vegetables, fruit, cereals, but also available as supplements) prior to and during the first three months of pregnancy, to reduce the risk of neural tube defects such as spina bifida. Excessive exercise can lead to menstrual disorders in women and affect sperm production in men due to the heat build-up around the testicles. Avoid environmental poisons and hazards such as pesticides, lead, heavy metals, toxic chemicals, and ionising radiation.