Introduction to infertility, causes of infertility

Definition: Infertility is defined as a failure to conceive within one or more years of regular unprotected coltuse Two types: (1) Primary Infertility: Those patients who have

Two types: (1) Primary Infertility: Those patients who havenever conceived. (2) Secondary infertility: Those patients who have previous pregnancy but failure to conceive subsequently.

Incidence

• 80% couples achieve conception if they so desire.
• 10% couples achieve conception at the end of second year.
• 10% couples remain infertile.

Fertility Responsible Factors in

Females

1. Ovarian factor (ovulation)
2. Tubal factor: The fallopian tubes should be patent.
3. The embryo should reach the uterine cavity after 3-5 days of fertilization.
4. The endometrium should be receptive for implantation and the corpus luteum should function adequately.

Males

1. Healthy spermatozoa should be deposited high in vagina
2. Spermatozoa should undergo changes (capacitation, aerosome reaction) and acquire motility.
3. Motile spermatozoa should ascend through the cervix into the uterine cavity and fallopian tubes.
4. The spermatozoa should fertilize the oocyte at the ampulla of the tube.

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Causes of Infertility

1. Conception depends on the fertility potential of both the male and female partners.

2. The male is directly responsible in about 30-40%.

Female: 40-55%

Both: 10%

Remaining 10% are unexplained.

Male Infertility Causes

1. Defective spermatogenesis
2. Obstructions of efferent duct system
3. Failure to deposit sperm high in the vagina
4. Errors in the seminal fluid

Defective Spermatogenesis

a) Follicle stimulating hormone stimulates spermatogenesis from basal cells of the seminiferous tubules.

b) FSH stimulates the sertoli cells to produce androgen binding proteins (ABP) and inhibin B.

c) ABP binds to testesterone and dehydrotestesterone to maintain the local high concentration of androgens. i.e. important for spermatogenesis.

d) Approximately 14 days are required to complete the process of spermatogenesis.

Congenital Defects

a) Undescended testes: Vas deferens is absent in about 1-2% of infertile males.

b) Kartagener syndrome: There is loss of ciliary function and sperm motility.

c) Hypospadias: Failure to deposit sperms high in vagina.

Other Factors

a) Thermal factor: Raised scrotal temperature, working in hot atmosphere.

b) Infection: Mumps, Orchitis, T. Mycoplasma or Chlamydia trachomatis infection is also implicated.

c) Endocrine factor: Testicular failure due to gonadotrophin deficiency is rare. Hyper prolactinaemia is associated with impotence.

d) Genetic: Common chromosomal abnormality azoospermia in males is Klinefelters syndrome (47 XXY)

e) Iatrogenic factors: Radiation, cytotoxic drug nitrofurantoin, cimetidine, Beta blockers, antihypertensive, anti convulsants and anti depressant drugs are likely to hinder spermatogenesis.

Immunological factors: Presence of antisperm antibodies.

Obstruction of efferent duct

The efferent ducts may be obstructed by infection like tubercular, gonococcal or by surgical trauma.

Failure to deposit sperms high in vagina (local problem)

Erectile dysfunction. Ejaculatory defects, hypospadias.

Sperm in the seminal fluid

Unusually high or low volume of ejaculate, low fructose content. High prostaglandin contente

Investigations

1. Semial fluid analysis.
2. Routine urine analysis, Hb, fasting and post prandial sugar
3. Serum FSH, LH, Testosterone, Prolactin and TSH
4. Testicular biopsy
5. Transrectal ultrasound (ejaculatory duct obstruction)
6. Karyotype analysis (Genetic)
7. Immunological tests: Two types of antibodies: (1) Sperm agglutinating (2) Sperm immobilizing

Female Infertility Causes

1. Ovarian factor
2. Tubal and peritoneal factors
3. Uterine factors and cervical factors
4. Combined factors

Ovarian factor: It includes

• Anovulatory or oligo-ovulation
• Decreased ovarian reserve
• Luteal phase defects
• Luteinised unruptured follicles Investigations for diagnosis of ovulation
• Basal body temperature biphasic pattern
• Cervical mucosal study
• Vaginal cytology
• Hormone tests (LH, FSH, prolactin, progesterone, oetradiol)
• Endometrial biopsy
• Sonography
• Ovarian biopsy
• Laproscopy

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Physical Examination

Thorough systemic examination is essential to find out the disease conditions causing ED. Specially examination of nervous system which includes peripheral, spinal, supraspinal and both somatic and autonomic nervous systems to find out any neurological deficit. Examination of the peripheral pulses and blood pressure particularly femoral and if possible penile blood pressure to rule out peripheral vascular disorder. The endocrine system should be examined, particularly the breast for gynaecomastia to rule out hyperprolactinaemia. The testis and secondary sexual characteristics like axillary and pubic hair to rule out Hypogonadism and Hypopituitarism. Examination of the genitalia to rule out congenital and local mechanical causes of ED.

Laboratory Investigation

Baseline haematological and biochemical screens are necessary which includes Hb, TC, DC, ESR, liver function tests, renal function test (blood urea, serum creatinine). Random blood sugar, serum cholesterol to rule out anaemia, infection, hepatic and renal impairment, diabetes mellitus and hyper cholesterolaemia. link

Urine analysis to rule out urinary tract infections and hormonal evaluation if needed as they are highly expensive. It includes measurement of Serum Testosterone, S. DHEA-S, Prolactin, Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) to rule out hypogonadism or androgen deficiency, hyperprolactinaemia and hypopituitarism.