Infrequent periods

• Disease name: Oligomenorrhea (Oligomenorrhea)

Disease Description (Causes and Symptoms)

Definition

• A condition in which the interval between menstrual periods becomes 35 days or longer. It may recur regularly at intervals of 40–45 days, or present as irregular bleeding only about 3–4 times per year.

Main Causes and Pathophysiology

• Functional causes (most common): hormonal imbalance in the hypothalamic–pituitary–ovarian axis (HPO axis) or insufficient secretion of female hormones (estrogen and progesterone) → anovulation or oligo-ovulation.
• Endocrine disorders: hypothyroidism/hyperthyroidism, hyperprolactinemia (including pituitary tumors).
• Polycystic ovary syndrome (PCOS): associated with anovulatory oligomenorrhea.
• Ovarian insufficiency (primary or secondary ovarian failure).
• Structural causes within the uterus: endometrial damage (Asherman syndrome), uterine or fallopian tube abnormalities, uterine polyps or fibroids, etc.
• History of infection/surgery: repeated induced abortions or endometrial damage.
• Systemic diseases: malabsorption such as celiac disease, rapid weight changes or malnutrition, excessive exercise, and stress.
• Medication or surgical causes: antipsychotics/antidepressants, radiation therapy, etc.

Main Symptoms

• Prolonged interval between menstrual periods (the key symptom), infertility due to anovulation, and sometimes headaches, shoulder pain, acne, etc. (particularly when accompanied by endocrine abnormalities).
• Symptoms vary from mild to almost nonexistent.

Risk of Complications

• Persistent anovulation increases the risk of endometrial hyperplasia and, in the long term, endometrial cancer.
• Infertility, osteoporosis (chronic hypoestrogenic state), and metabolic syndrome (particularly related to PCOS).

Treatment Methods

Standard treatment according to the cause following a diagnostic evaluation

• Basic tests and correction of the cause: pregnancy test (always the first test), TSH (thyroid), blood prolactin, FSH/LH, estradiol, androgen levels (if necessary), blood glucose and lipids, celiac disease testing (if suspected), pelvic ultrasound (evaluation of the ovaries and uterus), and brain MRI if a pituitary lesion is suspected.
• Hormone therapy (regulation of the menstrual cycle and protection of the endometrium)
  • Cyclic progestin (e.g., medroxyprogesterone) to induce withdrawal bleeding or protect the endometrium.
  • Combined oral contraceptives (OC) to regulate the menstrual cycle and protect the endometrium.
• Ovulation induction (if pregnancy is desired)
  • First-line medication: letrozole — recommended as the first-line treatment for patients with PCOS.
  • Clomiphene citrate — an alternative.
  • Follicle-stimulating hormone (FSH)/artificial ovulation (ovarian stimulation) and assisted reproductive technology if unresponsive to medication.
  • Dopamine agonists (such as cabergoline) when hyperprolactinemia is the cause.
• Treatment of the underlying condition
  • Thyroid dysfunction: thyroid hormone therapy (hypothyroidism) or antithyroid medication (hyperthyroidism).
  • Intrauterine adhesions (Asherman syndrome): hysteroscopic adhesiolysis.
  • Pituitary tumor: consultation with endocrinology/internal medicine and neurosurgery, with medication (dopamine agonists) or surgery/radiation therapy.
• Lifestyle modification
  • Weight management (weight loss for overweight/obesity and weight gain for underweight), regular exercise (avoid excessive exercise), a balanced diet, and stress management.
  • For patients with PCOS, management of metabolic risks (diet and exercise; consider metformin if necessary).

Precautions and Monitoring

• Confirm whether the patient is pregnant before treatment.
• When inducing ovulation, explain and monitor the risks of multiple ovulation, ovarian hyperstimulation syndrome (OHSS), and multiple pregnancy.
• In patients with chronic anovulation, regular hormone therapy or observation is necessary to protect the endometrium.
• Immediate medical attention is necessary if symptoms suggesting a pituitary lesion, such as severe headache or changes in vision, occur.

Checklist Before an Outpatient Visit (Including Preparation and Example Questions)

Items/Information to Provide

• Menstrual records from the past 6–12 months (menstrual start dates, duration, changes in bleeding volume, and intervals).
• A list of currently taken medications and supplements (dosage and duration of use).
• Copies of previous medical records and test results (pregnancy tests, thyroid and prolactin tests, pelvic ultrasound, MRI, etc.), if available.
• Records of weight changes, diet, exercise habits, and stress factors.
• History of gynecologic surgery (uterine procedures, D&C, etc.) and pregnancy or miscarriage.
• Fertility goals (whether pregnancy is desired) and contraceptive history.

Useful Materials to Provide to the Doctor During the Visit

• A menstrual calendar (with dates and detailed symptoms, if possible).
• Recent blood test results, if available.

Simple Examples of Questions (Useful for the Patient to Write Down in Advance)

• How have the intervals between menstrual periods and the amount of bleeding changed over the past few months?
• Have there been any changes in weight, amount of exercise, or diet?
• Have you experienced symptoms such as nipple discharge, persistent headaches, or changes in vision?
• Do you want to become pregnant? Have you previously received ovulation induction or assisted reproductive technology?

General Examples of Questions to Ask the Doctor

• What is the most likely cause of this condition?
• What additional tests (blood tests or imaging) are recommended?
• What are the current treatment options, and what are the advantages and disadvantages of each?
• What are the main side effects and precautions of the medication I plan to take (or have been prescribed)?
• If I want to become pregnant, what is the prognosis (chance of pregnancy)?
• If menstruation normalizes with treatment, how often should I have follow-up tests?

Examples of Condition-Specific Questions

• PCOS is suspected. In my case, would you recommend letrozole as the first ovulation-inducing medication? What are its effectiveness and risks?
• My prolactin level was high. Do I need a brain MRI? (Ask in relation to whether symptoms such as headaches or visual disturbances are present.)