Infertility

Infertility is the inability to naturally conceive a child or the inability to carry a pregnancy to term. There are many reasons why a couple may not be able to conceive, or may not be able to conceive without medical assistance.

Causes

Primary vs. secondary

According to the American Society for Reproductive Medicine, infertility affects about 6.1 million people in the U.S., equivalent to ten percent of the reproductive age population. Female infertility accounts for one third of infertility cases, male infertility for another third, combined male and female infertility for another 15%, and the remainder of cases are "unexplained"{{fn|2}}.

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A Robertsonian translocation in either partner may cause recurrent abortions or complete infertility.

Related Topics:
Robertsonian translocation - Recurrent abortions

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"Secondary infertility" is difficulty conceiving after already having conceived and carried a normal pregnancy. Apart from various medical conditions (e.g. hormonal), this may come as a result of age and stress felt to provide a sibling for their first child. Technically, secondary infertility is not present if there has been a change of partners.

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Female infertility

Factors relating to female infertility are:

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• General factors
• Diabetes mellitus, thyroid disorders, adrenal disease
• Significant liver, kidney disease
• Psychological factors
• Hypothalamic-pituitary factors:
• Kallmann syndrome
• Hypothalamic dysfunction
• Hyperprolactinemia
• Hypopituitarism
• Ovarian factors
• Polycystic ovary syndrome
• Anovulation
• Diminished ovarian reserve
• Luteal dysfunction
• Premature menopause
• Gonadal dysgenesis (Turner syndrome)
• Ovarian neoplasm
• Tubal/peritoneal factors
• Endometriosis
• Pelvic adhesions
• Pelvic inflammatory disease (PID, usually due to chlamydia)
• Tubal occlusion
• Uterine factors
• Uterine malformations
• Uterine fibroids (leiomyoma)
• Asherman's Syndrome
• Cervical factors
• Cervical stenosis
• Antisperm antibodies
• Vaginal factors
• Vaginismus
• Vaginal obstruction
• Genetic factors
• Various intersexed conditions, including Androgen Insensitivity Syndrome
• Transsexuality in the case of transsexual women

Male infertility

Factors relating to male infertility include{{fn|3}}:

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• Pretesticular causes
• Endocrine problems, i.e. diabetes mellitus, thyroid disorders
• Hypothalamic disorders, i.e. Kallmann syndrome
• Hyperprolactinemia
• Hypopituitarism
• Hypogonadism due to various causes
• Psychological factors
• Drugs, alcohol
• Testicular factors
• Genetic causes, e.g. Klinefelter syndrome
• Neoplasm, e.g. seminoma
• Idiopathic failure
• Varicocele
• Trauma
• Hydrocele
• Mumps
• Posttesticular causes
• Vas deferens obstruction
• Infection, e.g. prostatitis
• Retrograde ejaculation
• Hypospadias
• Impotence
• Genetic causes
• Various intersexed conditions, including Klinefelter's Syndrome
• Transsexuality in the case of transsexual men

Some causes of male infertility can be determined by analysis of the ejaculate, which contains the sperm. The analysis includes counting the number of sperm and measuring their motility under a microscope:

Related Topics:
Ejaculate - Sperm - Motility - Microscope

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• Producing few sperm, oligospermia, or no sperm, azoospermia.
• A sample of sperm that is normal in number but shows poor motility, or asthenozoospermia.

Combined infertility

In some cases, both the man and woman may be infertile or sub-fertile, and the couple's infertility arises from the combination of these conditions. In other cases, the cause is suspected to be immunological or genetic; it may be that each partner is independently fertile but the couple cannot conceive together without assistance.

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Unexplained infertility

In about 15 % of cases the infertility investigation will show no abnormalities. In these cases abnormalities are likely to be present but not detected by current methods. Possible problems could be that the egg is not released at the optimum time for fertilization, that it may not enter the fallopian tube, sperm may not be able to reach the egg, fertilization may fail to occur, transport of the zygote may be disturbed, or implantation fails. It is increasingly recognized that egg quality is of critical importance and woman of advanced maternal age have eggs of reduced capacity for normal and successful fertilization.

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