What is infertility?
Infertility, or subfertility, occurs when a couple is unable to conceive a child within one year of trying. Infertility may also prevent a pregnancy from continuing. It should be noted that infertility does not mean one is sterile. Sterility means one is unable to conceive, whereas infertility means that becoming pregnant may be difficult, but not impossible.

Symptoms
Many signs or symptoms of infertility are not obvious. Some women may experience irregular menstrual periods or disorders that make menstruation or intercourse painful. However, pain during menstruation or intercourse does not necessarily mean that a woman is infertile. Likewise, most men show few, if any, symptoms of infertility. If they do show symptoms, the symptoms may include a change in hair-growth pattern, breast enlargement, change of voice or difficulty obtaining or maintaining an erection.

Causes of infertility
Although males present more often than women as the cause of infertility, infertility may involve both partners. For men, problems may range from abnormal sperm production to erectile dysfunction to stress. For women, problems may include tubal damage, anorexia, or premature menopause. Below are more detailed descriptions of many causes of infertility in both men and women.

Causes of male infertility

• Abnormal shape and movement of sperm. If the shape of the sperm is abnormal or movement is impaired, sperm may not be able to reach the egg to fertilize it.
• The absence of sperm production, although this is relatively rare.
• Low sperm concentration
• Undescended testicles, that is the failure of one or both one or both testicles to descend from the abdomen into the scrotum during fetal development. The relatively higher temperature of an undescended testicle compared with a descended testicle can impair sperm production and lead to infertility.
• Deficiency of testosterone levels resulting from disorders of the testicles themselves or the glands in the brain that produce the hormones that control the testicles
• Varicocele, which is a varicose vein found in the scrotum. The vein may prevent proper cooling of the testicle and as a result prevent sperm from surviving
• Klinefelter?s syndrome, which causes abnormal development of the testicles including low or absent sperm production
• Sexually transmitted diseases such as Chlamydia, gonorrhea,and syphilis may cause infertility in men because of scar tissue resulting in blockage of sperm passage
• Mumps in adults
• Inflammation of the prostate, urethra, or epididymis
• Erectile dysfunction, premature ejaculation, painful intercourse or psychological stress
• Blockage of the part of the testicle that contains sperm or the ejaculatory ducts
• The presence of anti-sperm antibodies after a vasectomy
• Cystic fibrosis, which may lead to an obstructed vas deferens
• Severe or prolonged emotional stress may interfere with the hormones needed for sperm production
• Malnutrition that leads to deficiencies in essential vitamins and minerals
• Obesity or a relatively high body mass
• Radiation and chemotherapy for cancer treatment
• Excessive alcohol consumption and certain drugs, such as anabolic steroids, cocaine and even marijuana
• Diabetes
• Heart disease
• Aging
• Exposure to chemicals, such as benzene, toluene, xylene as well as solvents used in common household materials such as glues, paint and varnishes
• Elevated core body temperature from illness, hot tubs, and saunas can impair sperm production
• Tobacco use

Causes of female infertility

• Fallopian tube damage or complete blockage in which a woman?s fertilized egg cannot travel through the fallopian tube to the uterus for implantation
• Endometriosis, which causes the tissue that lines the uterus to grow outside the uterus ultimately causing scarring and inflammation
• Ovarian cysts, which may be a sign of advanced endometriosis
• Various hormone irregularities including those caused by pituitary tumors, excessive exercise, and anorexia nervosa
• Premature menopause, including the absence of menstruation and the depletion of ovarian follicles before age 35
• Autoimmune disease
• Radiation or chemotherapy
• Tobacco use
• Uterine fibroids
• Pelvic adhesions most often caused by abdominal or pelvic surgery, pelvic infection, appendicitis
• Medications
• Thyroid disorders
• Cancer
• Cushing?s disease
• Sickle cell disease
• HIV/AIDS
• Kidney disease
• Diabetes

Risk factors
Risk factors for infertility include the following for both men and women:

• Age. A woman?s fertility declines in her early 30s and her risk of miscarriage increases. Likewise, men see a decline in their fertility by their mid-30s.
• Smoking, which decreases fertility and increases the risk of miscarriages
• Excessive alcohol consumption
• Body mass that is either too high or too low; that is greater than 25.00 and lower than 20.0
• Being overweight or underweight

Screening and diagnosis
Several tests are available for determining causes of infertility. A couple and their physicians should decide what diagnostic tests and treatments are best suited for their individual circumstances.

Tests for men

• General physical. This exam includes a thorough work up of the man?s medical history, including illnesses, disabilities, medications, sexual habits, and examination of the genitals.
• Semen analysis. A man?s semen will be analyzed for quantity, color, sperm count, sperm movement, and the presence of infection and blood.
• Hormone testing. This test will determine the levels of male hormones, including testosterone. 

Tests for women

• General physical. This exam includes a thorough work up of the woman?s medical history, including illnesses, medications, menstrual history, sexual habits, and gynecological examination.
• Blood test. A blood sample may be taken to check for hormone levels that would indicate ovulation.
• Hysterosalpingography. This test evaluates whether there are blockages involving the uterus and fallopian tubes.
• Laparoscopy. This surgical procedure allows the doctor to view the fallopian tubes, ovaries, and uterus to check for blockages, scarring or endometriosis.

Treatments
Treatments vary according to the cause of infertility, the age of the couple, and the duration of the condition. Following are some of the possible treatments for infertility; however, you and your doctor should decide which ones are right for you.

Possible treatments involving each partner

• Fertility drugs, i.e., drugs that induce ovulation. These drugs may include:
  • Clomiphene citrate (Clomid, Serophene), which stimulates ovulation
  • Human menopausal gonadotropin, or hMG (Repronex, Pergonal), which is for women who don't menstruate on their own. This drug directly stimulates the ovaries.
  • Follicle-stimulating hormone, or FSH (Gonal-F, Follistim, Bravelle). FSH works by stimulating the ovaries to mature egg follicles.
  • Human chorionic gonadotropin, or hCG (Ovidrel, Pregnyl). This drug also stimulates ovulation.
  • Gonadotropin-releasing hormone (Gn-RH) analogs. This treatment is for women with irregular ovulatory cycles or who ovulate prematurely.
  • Metformin (Glucophage). This drug boosts ovulation and is used when insulin resistance is known or suspected.
• Surgery may be needed to treat blockages of the fallopian tubes.
• In vitro fertilization (IVF). This treatment involves fertilizing a woman?s eggs in the laboratory and implanting the embryos in the uterus.
• Intraccytoplasmic sperm injection (ICSI). This technique involves the injection of a single sperm injected directly into an egg.
• Assisted hatching. This treatment assists with the implantation of an embryo into the lining of the uterus.
• Treating impotence or premature ejaculation with medications or behavior modification.
• Increasing sperm count with surgery, antibiotics (for infections), or in some cases hormones.

Complications

• Multiple pregnancies
• Low birth-weight babies
• Birth defects
• Ovarian hyperstimulation syndrome (OHSS). This occurs when a woman's ovaries become enlarged causing pain and bloating.