Infertility

infertility is defined as the failure to conceive within one year of unprotected regular sexual intercourse. Infertility is said to be primary if no previous conception occur while it is called secondary if previous conception occur whatever its fate.

Infertility affects about 15 % of couples. The single most important factor in determining fertility is the age of the female, fertility rapidly reducing after the age of 35 years. Other factors that reduce the chance of spontaneous conception include:
• Duration of infertility more than 3 years.
• Low coital frequency.
• No previous pregnancy.
• Smoking.
• Body mass index out side the range 20-30 kg/m2 (weight/height2) in women.
• Low number of motile healthy sperms.

Causes of infertility:
The main causes of infertility are anovulation, male factor, tubal damage & unexplained. Other causes include endometriosis & fibroids. Tubal factor is more common in patient with secondary infertility.
Ovulatory disorders:
Ovulation problems can arise as a result of a defect in the hypothalamus, pituitary or the ovary. Factors that affect the pulsatile release of GnRH will lead to disordered ovulation. These factors include stress, psychological disturbances, weight change & systemic diseases as well as tumours & structural lesions in the hypothalamus.
Hypothyroidism & hyperthyroidism may cause ovulatory failure. Hyperprolactinaemia, renal failure, hepatic dysfunction & phenothiazin drug reduce the pulsatile release of GnRH leading to anovulation.
The commonest cause of anovulatory infertility is polycystic ovary syndrome (PCOS). Women affected by this condition have a range of symptoms that include: menstrual cycle disturbance (oligomenorrhea or amenorrhea), obesity, hirsutism, acne & subfertility.
Premature ovarian failure is a condition in which the ovaries fail before the age of 40 years. It is characterized by amenorrhea, raised FSH & low serum estradiol. The aetiology include genetic defect (e.g. Turner syndrome), damage due to viral infection, toxins, pelvic surgery, irradiation & cytotoxic drugs, also autoantibodies affecting the ovaries.

Tubal dysfunction:
Tubal damage may result from pelvic infection, endometriosis or pelvic surgery. This damage may cause impaired oocyte pick-up mechanisms by the fimbriae or to damaged tubal epithelium. Sexually transmitted disease caused by Chlamedia trachomatis or gonorrheare the most common cause in addition to pelvic sepsis following appendicitis & peritonitis.

Disorders of implantation:
This include defects related to endometrial development or the production of growth & adhesion molecules. Submucous fibroid may distort endometrial cavity & impair implantation.

Male factor:
• Disorders of spermatogenesis.
• Impaired sperm transport.
• Ejaculatory dysfunction.
• Immunological & infective factors.