Irregular Menstrual Cycles

  • Normal: 3 to 5 week cycle.
  • Hormone regulation:
    • GnRH → anterior pituitary releases FSH and LH. In first half of cycle, FSH predominates → ovarian follicles mature and release estrogen to induce endometrial proliferation. Mid-cycle LH surge → ovulation and formation of corpus luteum that secretes progesterone → compacts and matures the endometrium. If no pregnancy, progesterone drops off and menstruation occurs.
  • Consider:
    • PCOS, thyroid problems, whether the source of bleeding is elsewhere (vagina, rectum, cervix, etc), medications (anticoagulants, phenytoin, antipsychotics, TCAs, steroids), pregnancy, examine for galactorrhea
  • First, do a pregnancy test! Then check prolactin, LH, TSH, total testosterone

Heavy periods (menorrhagia) w/ regular intervals

  • suggests ovulation, endocrine pathways are working.
  • May have leiomyomata or polyps = increase the endometrial surface area
  • May have coagulopathy – most often VWF disease or anticoagulant meds, also liver disease or thrombocytopenia

Light periods with regular intervals

  • – suspect Asherman syndrome, scarred, or obstructed cervical os.


  • PCOS → irregular heavy periods

    • Insulin resistance and androgen excess.
    • Diagnosis: Must have 2 of 3: hyperandrogenism, chronic anovulation (causes menstrual cycle abnormalities – no luteal production of progesterone), and polycystic ovaries by ultrasound.
    • Labs: measure serum total testosterone and sex hormone binding protein → calculate Free T.
    • Treatment:
      • Induce periods w/ periodic supplemental progesterone or with OCPs.
      • Insulin issues: use metformin and thiazolidinediones (glitazones; work by activating PPAR-gamma)
      • Infertility: clomiphene citrate, aromatase inhibitors, gonadotropins

Unpredictable timing and flow

  • Dysfunctional Uterine Bleeding (DUB) → abnormal hypothalamic-pituitary-ovarian axis.

    • Most often after menarche/before menopause. Can signal anovulation.
    • Management:
      • Watch for a few years after menarche.
      • < 35 y/o w/out risk factors for endometrial cancer → can treat without workup – use OCPs with combined estrogen and progestin or progestin alone.
      • Work up if > 35 y/o. risk factors for endometrial cancer, no response to treatment, or postmenopausal.
    • Diagnosis
      • Initial work up: check prolactin, LH, TSH, total testosterone
      • Transvaginal pelvic ultrasound and endometrial biopsy. Then hysteroscopy to visualize and direct any further biopsies – can do with D&C for diagnostic and therapeutic reasons.


  • Common cause of vaginal spotting.
  • Usually, polymicrobial infection ascended from vagina.
  • Can involve gonorrhea, chlamydia, ureaplasma, peptostreptococcus, gardnerella vaginalis, and group B strep.
  • Do endometrial biopsy – see inflamed cells, especially plasma cells.