Anovulation is a condition where the ovaries fail to release an egg during the menstrual cycle, a process known as ovulation. Since ovulation is key for fertilisation and conception, its absence often leads to difficulty getting pregnant. While some individuals may still experience bleeding that resembles a period, this is not true menstruation, as it doesn’t follow the natural hormonal rhythm of a cycle that includes ovulation.

In a typical menstrual cycle, ovulation occurs around the middle of the cycle—often near day 14 in a 28-day cycle. The process starts in the brain with the hypothalamus releasing gonadotropin-releasing hormone (GnRH), which signals the pituitary gland to produce follicle-stimulating hormone (FSH) and luteinising hormone (LH). FSH stimulates the development of follicles in the ovaries, and one of these follicles eventually matures and releases an egg in response to an LH surge. This coordinated hormonal event is essential for ovulation to occur.

Who Can Be Affected?

Anyone who has ovaries and is of reproductive age (typically between 12 and 51) can experience anovulation. It’s more commonly seen in:

• Teenagers who recently began menstruating
• Individuals approaching menopause (perimenopause)
• People with polycystic ovary syndrome (PCOS)
• Those with very low or high body weight
• Individuals under chronic physical or emotional stress

How Common Is It?

Anovulation accounts for approximately 30% of infertility cases, making it a significant concern for individuals trying to conceive.

Signs and Symptoms of Anovulation

Recognising anovulation involves paying attention to your cycle and body changes. Common signs include:

• Irregular periods (cycle length varies unpredictably)
• Very light or very heavy bleeding
• Missed periods (amenorrhea)
• Lack of fertile cervical mucus (clear, stretchy discharge during ovulation)
• Inconsistent basal body temperature (no post-ovulation temperature rise)

Causes of Anovulation

• Hormonal Imbalances o Disruption in key reproductive hormones like luteinising hormone (LH) and follicle-stimulating hormone (FSH) can interfere with the regular menstrual cycle and prevent ovulation.
• Polycystic Ovary Syndrome (PCOS) o This common hormonal disorder affects ovary function and is a leading cause of anovulation due to elevated androgen levels and irregular follicle development.
• Body Weight Issues o Both underweight and overweight individuals are at risk. Extreme body fat levels can alter hormone production and affect ovulation.
• Excessive Physical Activity o High-intensity workouts, especially when combined with low calorie intake or low body fat, may suppress the hormones necessary for ovulation.
• Chronic Stress o Long-term emotional or physical stress can impair the hypothalamus, a brain region that helps regulate the menstrual cycle, thus halting ovulation.
• Premature Ovarian Insufficiency (Early Menopause) o When ovaries stop functioning before the age of 40, it can result in absent ovulation and irregular or missed periods.

• Medical Conditions

o Disorders such as hypothyroidism, hyperthyroidism, and pituitary gland abnormalities (like tumors) can all interfere with normal ovulatory function.

Can You Bleed Without Ovulating?

Yes. While true menstruation follows ovulation, some individuals may experience anovulatory bleeding, which is irregular and not part of a typical cycle. This is due to hormonal fluctuations rather than the usual ovulation process.

What Causes Anovulation?

The root of anovulation is usually a hormonal imbalance. The hormones involved in the ovulation process include:

• GnRH (from the hypothalamus)
• FSH and LH (from the pituitary gland)
• Estrogen and progesterone (from the ovaries)

Disruptions in this hormone cascade can be caused by:

• High androgen levels (often seen in PCOS)
• Pituitary gland issues (like tumors or Sheehan’s syndrome)
• High prolactin levels (due to tumors or medications)
• Underactive thyroid (hypothyroidism)
• Low GnRH levels (due to hypothalamic dysfunction from stress, extreme weight changes, or excessive exercise)

Risk Factors for Anovulation

• Have PCOS
• Are overweight or underweight
• Engage in intense or prolonged exercise
• Experience chronic stress
• Are in a transitional reproductive stage (starting or nearing the end of menstruation)

Possible Complications

Untreated anovulation may lead to:

• Infertility
• Amenorrhea
• Hormonal imbalance symptoms (acne, weight gain, hair thinning)
• Endometrial hyperplasia (abnormal thickening of the uterine lining)
• Osteoporosis and cardiovascular risks (due to low estrogen levels)

How Is Anovulation Diagnosed?

Diagnosis typically starts with a review of menstrual history. If your periods are irregular or absent, your provider may order:

• Blood tests to check hormone levels (progesterone, thyroid, prolactin) • Ultrasound scans to assess ovarian function and follicle development

Treatment Options

• Lifestyle changes: Managing weight, reducing stress, and adjusting exercise habits
• Medications:

o Clomiphene citrate (e.g., Clomid) to induce ovulation o Letrozole (Femara), often used off-label for ovulation induction o HCG injections to trigger egg release o FSH injections to stimulate follicle development o GnRH agonists/antagonists to regulate LH production

If medications do not work, assisted reproductive techniques like IVF (in vitro fertilisation) or IUI (intrauterine insemination) may be recommended.

Can Anovulation Be Prevented?

Although not all causes are preventable, you can reduce your risk by:

• Maintaining a healthy body weight
• Eating a balanced diet
• Managing stress through relaxation techniques
• Tracking menstrual cycles to detect irregularities early
• Seeking treatment for conditions like PCOS or thyroid disorders

Prognosis and Outlook

The outcome depends on the cause. In many cases, lifestyle adjustments and medications can restore ovulation. If hormonal changes from aging (like perimenopause) are the cause, treatment focuses more on symptom management than restoring fertility.

When to See a Doctor

Contact a healthcare provider if:

• Your periods are irregular, too heavy or light, or absent
• You’ve been trying to conceive for over 6–12 months without success
• You experience unusual vaginal bleeding or pelvic discomfort