Evidence-informed guide Glossary

Oligomenorrhea

Oligomenorrhea: infrequent periods, cycles longer than 35 days, a common sign of irregular ovulation in PCOS.

by Pasukan Editorial Panduan PCOS Last reviewed: 5 May 2026

Only a doctor can diagnose PCOS. This article is for education, not a substitute for medical advice.

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Why it matters for PCOS
FAQ
Sources

Oligomenorrhea is infrequent periods, with cycles longer than 35 days or fewer than eight periods a year.

Why it matters for PCOS

Oligomenorrhea usually signals irregular or absent ovulation, a core feature of PCOS. When ovulation does not happen on a regular schedule, the womb lining does not shed on time, so periods come late or are missed. Infrequent periods are one of the three Rotterdam criteria used to diagnose PCOS, alongside signs of high androgens and polycystic ovaries on ultrasound.

Although common in PCOS, infrequent periods can also stem from thyroid problems, high prolactin, stress, or significant weight change. For that reason, a doctor usually runs blood tests to rule out other causes before confirming PCOS.

This glossary is education, not diagnosis. For your own situation, ask a doctor or pharmacist.

FAQ

Frequently Asked Questions

What is oligomenorrhea?

Oligomenorrhea means infrequent periods, typically cycles longer than 35 days or fewer than eight periods a year. It differs from amenorrhea, which is the complete absence of periods.

How does oligomenorrhea relate to PCOS?

Infrequent periods usually point to irregular ovulation, a common feature of PCOS, and form part of the Rotterdam criteria used to diagnose it. But infrequent periods can also come from thyroid problems or high prolactin, so a doctor needs to check the cause.

Sources

Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group. Revised 2003 consensus on diagnostic criteria and long-term health risks related to polycystic ovary syndrome (PCOS). Human Reproduction. 2004.PubMed