Obstetrics and Gynecology/Menstrual Disorders

Dysmenorrhea

Definition

• Pain on menstruation.

Epidemiology

• Over 70% of women experience dysmenorrhea at some point.

Etiology, Risk Factors, and Pathophysiology

Primary dysmenorrhea

• Results from production of prostaglandins within 48 hours of menstruation that stimulates the myometrial cells to contract.

Secondary dysmenorrhea

• The result of a pathologic condition
  • Endometriosis, adenomyosis, cervical stenosis, vaginitis, psychological disturbance

 Cervicitis

Management

• Birth control pill
• GnRH analogues
• NSAIDs (effective in 80% of women)

Amenorrhea

Definitions

• Primary amenorrhea: failure to menstruate by 16 years of age with secondary sexual characteristics; failure to menstruate by 14 years of age without sexual characteristics; failure to mensturate with 2 years of sexual maturation.
• Secondary amenorrhea: failure to menstruate for 6 months with formerly normal menses; oligomenorrhea with less than 9 cycles per year.

Etiology, Pathophysiology, and Risk Factors for Amenorrhea

Etiologies include

• Müllerian agenesis (MRKH syndrome) in 10%
• Androgen insensitivity in 5%
• Imperforate hymen in 0.1%
• Transverse vaginal septum in 1/80000
• Ashermann's syndrome
• Enzymatic deficiency
• Premature ovarian failure
• Pituitary tumours
• FSH/LH mutations
• Pituitary space-occupying lesions
• Pituitary necrosis
• Inflammatory/infiltrative pituitary disease
• Pharmacologic prolactin stimulators
• Stress induced amenorrhea
• Isolated gonadotropin deficiency
• Infections
• Chronic disease
• Hypothalamic tumours
• Adrenal, thyroid, ovarian endocrine disease
• Metastatic carcinoma

Clinical Presentation and Diagnostic Approach

• Pregnancy must always be excluded.
• Measure FSH and prolactin
  • If FSH is low or normal
    • Chronic anovulation
    • Anatomic defect (Müllerian agenesis)
  • If FSH is elevated
    • Ovarian failure
  • If prolactin is elevated
    • MRI head for prolactinoma

• Karyotyping may be performed for the following indications
  • High FSH in a patient under 30 years of age
  • Height <147cm
  • Ambiguous genitalia (congenital adrenal hyperplasia)
  • Absent uterus

Management

Primary amenorrhea

• Restore ovulation with estrogen and progesterone
• Reassurance

Secondary amenorrhea

• Treat the underlying cause