Anovulation: signs, causes and treatment

Anovulation means an ovary does not release an egg during a menstrual cycle.

Without ovulation, the usual rise and fall of reproductive hormones is altered. Bleeding may become irregular or stop, and pregnancy cannot begin in that cycle because no egg is available for fertilisation. Occasional disruption can happen, while repeated anovulation warrants assessment.

Anovulation very commonly presents with irregular periods and commonly presents with trouble getting pregnant. Periods may be widely spaced, absent or unpredictable; bleeding can also be unusually light or heavy. Some people continue to have apparently regular bleeding, so a bleed alone does not confirm ovulation.

Other signs depend on the cause and can include acne, increased facial or body hair, milky nipple discharge, hot flushes, vaginal dryness, weight change, altered eating patterns or intense exercise.

Ovulation depends on coordinated signals between the brain, pituitary gland and ovaries. Polycystic ovary syndrome can disturb follicle development. Hypothalamic amenorrhoea may follow inadequate energy intake, marked stress or intensive exercise. Hyperprolactinaemia, thyroid disorders and premature ovarian insufficiency can also interrupt the hormonal sequence.

Pregnancy, breastfeeding, the transition towards menopause and some medicines can change or suppress ovulation, so context matters when interpreting a missed period.

The course follows the underlying cause. Ovulation may resume when a temporary trigger settles or a hormone disorder is treated. Some conditions cause recurring cycle disruption and need longer-term management. Because ovulation can occur before the next period, pregnancy may still be possible when cycles begin to recover.

Factors associated with anovulation include polycystic ovary syndrome, significant weight change, insufficient nutrition, sustained psychological stress, very demanding exercise, pituitary or thyroid disorders and approaching menopause. A risk factor is a prompt to assess the whole picture rather than proof of the diagnosis.

A clinician will review cycle dates, pregnancy possibility, medicines, weight or exercise changes, and signs of hormone imbalance. Testing may include a pregnancy test and blood tests for progesterone, thyroid function, prolactin and other reproductive hormones. The timing of progesterone testing should reflect the individual cycle rather than a fixed calendar day.

Pelvic ultrasound can examine the ovaries and womb lining. Depending on the findings, further assessment may focus on the pituitary gland, ovarian function or metabolic health.

Management first addresses the driver where possible. This may mean restoring adequate nutrition and energy balance, reviewing a medicine, or treating thyroid disease or elevated prolactin. With polycystic ovary syndrome, lifestyle support and metformin may be suitable for selected people.

If pregnancy is desired, ovulation induction uses medicine with monitoring to encourage egg release. Ovarian drilling is a surgical option used selectively for polycystic ovary syndrome when other approaches are unsuitable. If pregnancy is not currently wanted, hormonal treatment may regulate bleeding and protect the womb lining but does not necessarily restore ovulation.

Record bleeding days, symptoms, medicines, major stress, exercise and weight changes. Home ovulation tests may be difficult to interpret in some hormone conditions and cannot identify every cause. Discuss contraception if pregnancy is not planned, because ovulation may return unpredictably.

Repeated anovulation can make conception difficult. When oestrogen acts on the womb lining without regular progesterone exposure, the lining may become excessively thick and bleeding can become heavy or erratic. Low-oestrogen causes may affect bone health, while the underlying disorder may have additional health effects requiring separate care.

Not every cause is preventable. Consistent nourishment, sustainable exercise, stress support and early review of persistent cycle changes can reduce avoidable disruption or identify a treatable problem. Do not stop prescribed medicine without discussing the reason and alternatives with its prescriber.

A gynaecologist can investigate irregular or absent periods. A reproductive endocrinologist or fertility specialist is appropriate when conception is the goal, while an endocrinologist may help with pituitary, thyroid or prolactin disorders. Seek urgent care for severe pelvic pain, fainting or heavy bleeding with weakness or breathlessness.