Oligomenorrhoea is infrequent menstruation defined by a cycle length between 6 weeks and 6 months.
At one extreme, it overlaps with normal, the cycles being ovulatory but infrequent; at the other, with amenorrhoea. Oligomenorrhoea may be due to any of the disorders associated with amenorrhoea except primary failure of elements of the hypothalmic-pituitary-ovarian axis which cause permanent amenorrhoea.
Oligmoenorrhoeic cycles may be ovulatory or anovulatory. If infertility is a concern and discrete endocrine disorders have been excluded, treatment of oligomenorrhoea should first be with clomiphene, and if this is unsucessful, with pulsatile GnRH or human gonadotrophins.
Last reviewed 01/2018