Abnormal Uterine Bleeding

Normal Uterine Bleeding

Uterine bleeding normally occurs every month during ovulatory cycles (menses) – regular, self limited, and manageable

timing and extent of bleeding depends on hormonal, clotting and endometrial factors

normally occurs every 24-35 days (but can be as short as 21 days)

Sequence: progesterone withdrawal (due to involution of corpus luteum) Þ vasospasm Þ ischemia Þ sloughling Þ

platelet plugs Þ surface healing (via estrogen; this takes several days)

Abnormal Bleeding – defined as Ý amount and/or Ý frequency, or any bleeding after menopause

Menorrhagia – excessively heavy bleeding (>80cc; normal is <35cc)

Intermenstrual bleeding – bleeding at a time other than menses, may be due to an anatomical lesion

post-coital bleeding – local vaginal or cervical lesion (e.g. cervical polyps, "strawberry cervix" cervicitis)

Ovulatory menorrhagia – due more endometrium or less stable endometrium

associated with adenomyosis and fibroids (greater surface area?)

How is normal bleeding distinguished from abnormal bleeding?

pre-menopausal

Subjective assessment – inaccurate, not helpful

Pad counts – imprecise due to huge variation in absorptive ability of many products

Hemoglobin – indirect; useful for women with fibroids (may not perceive excess bleeding because they’re used to it)

Menstrual record – (1) interval; (2) pattern; (3) length in days; (4) molimina (premenstrual symptoms) PMS

useful to figure out if someone is ovulating

Single episode vs. recurrent pattern – important to establish during history taking

post-menopausal

All post-menopausal bleeding is abnormal; "Post-menopausal bleeding is cancer until proven otherwise."

Exception: cyclic withdrawal bleeding on hormone replacement therapy can be normal

Causes of Intermenstrual Bleeding

Intrauterine lesion that does not respond to normal hormonal control of the menstrual cycle

e.g. endometrial polyp(s) if ulcerated (if not cycling); submucous leiomyoma; patient can still have normal cycle
an extrauterine lesion – cervicitis, cervical polyp, etc.

Pregnancy – during 1^st trimester, pregnancy not visible

implantation bleeding is normal; all other causes pathological (threatened miscarriage)

Dysfunctional Uterine Bleeding (DUB) – endometrial bleeding in the absence of uterine pathology

occurs most often at extremes of reproductive ages

usually caused by hormonal abnormalities – four etiologies:

(1) estrogen withdrawal – lack of estrogen

Examples: medication effect, hysterectomy, newborns (withdrawal of maternal hormones), "Midcycle Spotting" may be due to E drop after LH surge

(2) progestin withdrawal – endometrium is already estrogenized, so progesterone is dominant

Examples: normal menses, oral contraceptive pill "periods"

(3) estrogen breakthrough – chronic estrogen stimulation causes thick, unstable endometrium

most common cause of DUB; severe clinical symptoms (can get quite anemic)
no ovulation; estrogen levels at normal or above-normal levels; endometrium gets thicker and unstable

Examples: anovulatory bleeding (polycystic ovarian syndrome), post-menopausal unopposed estrogen use

(4) progestin breakthrough – chronic progesterone stimulation causes atrophic endometrium

Examples: depo and medroxy-progesterone acetate; breakthrough bleeding on oral contraceptives

Treatment: Oral Contraceptives, cyclic progestins

necessary to treat chronic cases due to Ý risk of endometrial cancer and Ý risk of hemmorrhage

Medications that can lead to abnormal uterine bleeding either by hormones or coagulation effects

Hormonal Effects: estrogens, progestins, androgens, medications that Ý prolactin, psychiatric durgs

usually associated with breast fullness and breast discharge

Coagulation Effects: anti-coagulants, non-steroidals (role unclear), cytotoxic chemotherapy (via thrombocytopenia)

Systemic illnesses can lead to abnormal uterine bleeding by way of hormone or coagulation dysfunction

Hormonal Effects: Hypothyroidism, Hormone-secreting tumor, chronic illness

Coagulation Effects: coagulopathy – Von Willebrand Disease, Leukemia, etc.