Infertility is the failure of conception in a couple having regular, unprotected coitus for one year, provided that normal intercourse is occurring not less than twice weekly.
The time period is arbitrary. It relates to the natural rates of conception, ie 80% of couples will be pregnant after 12 cycles. Of those who have not conceived after 12 cycles, about 50% will conceive during a second year of attempted conception. After this second year of attempted conception, the chances of conception in those couples remaining is about 50% in the following four years.
Primary infertility applies to a couple without a prior pregnancy. Secondary infertility is used when the couple have previously succeeded in achieving at least one pregnancy, including abortion and ectopic pregnancy.
The main causes of infertility in the UK are (percent figures indicate approximate prevalence):
- unexplained infertility (no identified male or female cause) (25%)
- ovulatory disorders (25%)
- tubal damage (20%)
- factors in the male causing infertility (30%)
- uterine or peritoneal disorders (10%).
In about 40% of cases disorders are found in both the man and the woman. Uterine or endometrial factors, gamete or embryo defects, and pelvic conditions such as endometriosis may also play a role.
A woman of reproductive age who has not conceived after 1 year of unprotected vaginal sexual intercourse, in the absence of any known cause of infertility, should be offered further clinical assessment and investigation along with her partner (1)
A woman of reproductive age who is using artificial insemination to conceive (with either partner or donor sperm) should be offered further clinical assessment and investigation if she has not conceived after 6 cycles of treatment, in the absence of any known cause of infertility. Where this is using partner sperm, the referral for clinical assessment and investigation should include her partner (1)
Offer an earlier referral for specialist consultation to discuss the options for attempting conception, further assessment and appropriate treatment where:
- the woman is aged 36 years or over
- there is a known clinical cause of infertility or a history of predisposing factors for infertility
Given the range of causes of fertility problems, the provision of appropriate investigations is critical.
- investigations include semen analysis; assessment of ovulation, tubal damage and uterine abnormalities; and screening for infections such as Chlamydia trachomatis and susceptibility to rubella.
Once a diagnosis has been established, treatment falls into 3 main types:
- medical treatment to restore fertility (for example, the use of drugs for ovulation induction)
- surgical treatment to restore fertility (for example, laparoscopy for ablation of endometriosis)
- assisted reproduction techniques (ART) - any treatment that deals with means of conception other than vaginal intercourse. It frequently involves the handling of gametes or embryos
Last edited 03/2021 and last reviewed 02/2022