Hypomenorrhea

Specialty: Gynecology and breast.

• Very few rules
• low volume menstruation
• scant or very short menstrual bleeding

Why it occurs

• Functional or structural decrease in endometrial thickness due to the long-term use of combined hormonal contraceptives or pure progestogens (common physiological/iatrogenic cause)
• Mild or moderate Asherman syndrome (uterine synechiae)
• Thyroid insufficiency (both hypo and hyperthyroidism with a subacute clinical course)
• Initial phase of menopausal transition with low-stimulus anovulatory cycles
• Sheehan syndrome (postpartum panhypopituitarism due to pituitary necrosis after severe obstetric hemorrhage)

Initial workup

Systematic exclusion of pregnancy by testing for beta-hCG in urine or blood. Analytical determination of pituitary and target hormones: FSH, LH, Estradiol, Prolactin, TSH, free T4 and basal Cortisol if hypopituitarism is suspected. Detailed transvaginal ultrasound performed in the late luteal phase to measure endometrial thickness (linear or <5 mm endometrium suggests atrophy or synechiae). Diagnostic hysteroscopy if intrauterine uterine mechanical cause is suspected.

Standard management

• Pharmacological treatment is not required if the cause is prolonged use of hormonal contraceptives and the patient is informed about the benign nature of reactive endometrial atrophy. Correction with levothyroxine sodium if primary hypothyroidism is confirmed. Hormone replacement therapy (estrogen and progesterone) if the cause is hypogonadism or Sheehan syndrome (note: hypomenorrhea does not itself affect fertility unless it is due to a structural endometrial factor such as Asherman syndrome).