What criteria should I use to determine if a woman with irregular menstrual cycles should be referred for further fertility evaluation?

Criteria for referral of a woman with irregular menstrual cycles for further fertility investigations include:

• Referral should be considered if the woman has not conceived after 1 year of regular unprotected sexual intercourse, in the absence of any known cause of infertility.
• Women with prolonged irregular menstrual cycles should be offered serum progesterone testing timed according to their cycle length to confirm ovulation; if ovulation is not confirmed, further investigation is warranted.
• Measurement of serum gonadotrophins (follicle-stimulating hormone and luteinising hormone) should be performed in women with irregular cycles to identify ovulation disorders.
• Earlier referral is advised if the woman is aged 36 years or over or if there is a known clinical cause or history of factors predisposing to infertility.
• Prolactin and thyroid function tests are not routinely recommended unless there are symptoms suggestive of ovulatory disorder, galactorrhoea, pituitary tumour, or thyroid disease.

These criteria help identify women with ovulatory dysfunction or other fertility issues who would benefit from specialist assessment and management.

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