{"id":4422459,"date":"2025-01-11T19:53:57","date_gmt":"2025-01-12T01:53:57","guid":{"rendered":"https:\/\/myendoconsult.com\/learn\/topics\/uterine-cycle-and-menorrhagia\/"},"modified":"2025-01-11T20:04:33","modified_gmt":"2025-01-12T02:04:33","slug":"uterine-cycle-and-menorrhagia","status":"publish","type":"oen_topic","link":"https:\/\/myendoconsult.com\/learn\/topics\/uterine-cycle-and-menorrhagia\/","title":{"rendered":"Uterine Cycle and Menorrhagia"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">INFLUENCE OF GONADAL HORMONES ON THE FEMALE REPRODUCTIVE CYCLE FROM BIRTH TO OLD AGE<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">General Overview<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Primary gonadal hormones<\/strong> (estrogens, progestogens) maintain and nourish the reproductive tract and have widespread effects (skin, hair, skeleton, vascular, electrolytes, mood).<\/li>\n\n\n\n<li><strong>Ovarian secretions<\/strong> (chiefly estrogens) are crucial at every life phase: infancy, childhood, puberty, adult reproductive years, and senescence.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">INFANCY<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Newborn Estrogen Effects<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>High maternal estrogen<\/strong> crosses placenta \u2192 noticeable effects in the female neonate:\n<ul class=\"wp-block-list\">\n<li>Breast enlargement (\u201cwitch\u2019s milk\u201d sometimes exuded).<\/li>\n\n\n\n<li>External genitalia appear somewhat developed.<\/li>\n\n\n\n<li>Endometrium stimulated to proliferate.<\/li>\n\n\n\n<li>Vaginal epithelium: Stratified, cornified cells (estrogenic).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Regression After Birth<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Within ~1 week, these signs recede (low estrogen levels).<\/li>\n\n\n\n<li>Newborn ovaries: small, containing only primordial follicles; cannot produce significant estrogens.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">CHILDHOOD (Postnatal Recess to Pre-Puberty)<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Ovarian Changes<\/strong>\n<ul class=\"wp-block-list\">\n<li>Gradual increase in interstitial tissue (fibrous stroma) as many follicles undergo atresia.<\/li>\n\n\n\n<li>No functional follicular development capable of significant estrogen output.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Vaginal Cytology<\/strong>\n<ul class=\"wp-block-list\">\n<li>Shows predominantly basal\/parabasal cells with bacteria\/debris.<\/li>\n\n\n\n<li>No estrogen-induced cornification.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Breasts<\/strong>\n<ul class=\"wp-block-list\">\n<li>Remain infantile (no glandular development).<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">PUBERTY (Sexual Maturation)<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Early Pubertal Changes<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Uterus<\/strong>: First to respond to estrogens (endometrial proliferation with straight tubular glands).<\/li>\n\n\n\n<li><strong>Vagina<\/strong>: Thickens, becomes stratified; cornified cells in smears.<\/li>\n\n\n\n<li><strong>Ovarian Follicles<\/strong>: Progress beyond minimal layers \u2192 multiple granulosa layers, theca interna forming.<\/li>\n\n\n\n<li><strong>Breasts<\/strong>: Areola pigmentation; conical protuberance (thelarche).<\/li>\n\n\n\n<li><strong>Body Contours<\/strong>: Fat deposition (shoulders, hips, buttocks).<\/li>\n\n\n\n<li><strong>Hair<\/strong>: Adult pubic\/axillary patterns begin.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Gonadotropin-Ovarian Interplay<\/strong>\n<ul class=\"wp-block-list\">\n<li>Pituitary FSH and LH must cycle appropriately with ovarian estrogen\/progesterone to establish <strong>ovulatory<\/strong> cycles.<\/li>\n\n\n\n<li>Adolescence and menopause can feature irregular, often anovulatory cycles.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Menstrual Cycle Onset<\/strong>\n<ul class=\"wp-block-list\">\n<li>Occurs with rhythmic ovulatory cycles after some months\/years of initial irregularities.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">ADULT REPRODUCTIVE YEARS<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Mature Menstrual Cycle (28-day typical example)<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Menstrual Phase (days ~1\u20134)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Upper two-thirds of endometrium sloughed in 48\u201372 hrs.<\/li>\n\n\n\n<li>Endometrial surface rapidly repaired under rising estrogen from developing follicles.<\/li>\n\n\n\n<li>Vaginal smear: minimal estrogen effect.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Follicular (Proliferative) Phase (days ~5\u201313)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Ovarian follicles develop under <strong>FSH<\/strong> \u2192 produce <strong>estrogen<\/strong>.<\/li>\n\n\n\n<li>Endometrium thickens, glands elongate.<\/li>\n\n\n\n<li>Vaginal epithelium: progressively cornified cells.<\/li>\n\n\n\n<li>One follicle typically achieves dominance by ~day 12.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Ovulation (day ~14)<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>LH surge<\/strong> triggers ovulation of mature follicle.<\/li>\n\n\n\n<li>Rapid formation of corpus luteum \u2192 secretes <strong>progesterone<\/strong> (+some estrogen).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Luteal (Secretory) Phase (days ~15\u201326)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Endometrial glands: sawtooth secretory changes under <strong>progesterone<\/strong>.<\/li>\n\n\n\n<li>Vaginal smear: decreased superficial estrogenic cells, more folded intermediate cells (progesterone effect).<\/li>\n\n\n\n<li>If no fertilization, corpus luteum regresses ~day 26 \u2192 drop in progesterone\/estrogen.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Premenstrual (days ~26\u201328)<\/strong>\n<ul class=\"wp-block-list\">\n<li>Rapid hormone withdrawal \u2192 endometrium ischemic, breaks \u2192 menstruation day 28.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Additional Changes<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Breasts<\/strong>: Fully mature, with duct extension (estrogen) + alveoli (progesterone).<\/li>\n\n\n\n<li><strong>Premenstrual Edema<\/strong>: Estrogen and progesterone can cause generalized fluid retention, recognized as bloating\/weight gain.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Pregnancy<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Conception &amp; Early Placental Hormones<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Chorionic gonadotropin (hCG)<\/strong> from implanted embryo maintains corpus luteum \u2192 continued estrogen\/progesterone production for first ~3 months.<\/li>\n\n\n\n<li>Placenta takes over steroidogenesis after ~12 weeks.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>High, Increasing Estrogen &amp; Progesterone<\/strong> \u2192 no new ovulation (FSH\/LH suppressed).<\/li>\n\n\n\n<li><strong>Breasts<\/strong>: Duct\/alveolar proliferation (with <strong>pituitary prolactin<\/strong>); no full lactation until postpartum.<\/li>\n\n\n\n<li><strong>Vaginal Cytology<\/strong>: High progesterone \u2192 \u201cnavicular cells\u201d in smears.<\/li>\n\n\n\n<li><strong>Puerperium<\/strong>: Post-delivery, large estrogen\/progesterone withdrawal.\n<ul class=\"wp-block-list\">\n<li><strong>Prolactin + suckling reflex<\/strong> \u2192 lactation onset.<\/li>\n\n\n\n<li>Ovarian cycles suppressed in lactation (varies from months to >1 year).<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">MENOPAUSE AND SENESCENCE<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Menopause<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Average ~51.4 years.<\/li>\n\n\n\n<li>Ovaries lose functional follicles \u2192 <strong>low estrogen<\/strong> \u2192 <strong>high FSH<\/strong> (lack of negative feedback).<\/li>\n\n\n\n<li>Physical changes: atrophy of breasts, uterus, vagina; bone loss; skin thinning; vasomotor symptoms.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Premature Ovarian Failure<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Primary hypogonadism &lt;40 years.<\/li>\n\n\n\n<li>Similar changes to menopause.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Senile Changes<\/strong>\n<ul class=\"wp-block-list\">\n<li>Childhood and old age are relatively \u201cquiet\u201d gonadal phases.<\/li>\n\n\n\n<li>Without sufficient estrogen, many tissues revert to atrophic states (bone loss, dryness).<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\">FUNCTIONAL AND PATHOLOGIC CAUSES OF UTERINE BLEEDING<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Normal Menstrual Bleeding<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Definition<\/strong>\n<ul class=\"wp-block-list\">\n<li>The uterus is unique in undergoing cyclical necrosis and desquamation with bleeding as a healthy process.<\/li>\n\n\n\n<li><strong>Menstruation<\/strong>: Regular shedding of the superficial endometrium in response to rhythmic ovarian steroid (estrogen, progesterone) production.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Characteristics<\/strong>\n<ul class=\"wp-block-list\">\n<li>Typically <strong>2\u20137 days<\/strong> duration, <strong>&lt;80 mL<\/strong> total blood loss.<\/li>\n\n\n\n<li>Regular cycles: Evidence of a well-ordered hormonal interplay (pituitary-ovarian-endometrial axis).<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">ABNORMAL UTERINE BLEEDING (Menorrhagia, Metrorrhagia)<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Terminology<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Menorrhagia<\/strong>: Heavy or prolonged menstrual flow.<\/li>\n\n\n\n<li><strong>Metrorrhagia<\/strong>: Bleeding at irregular intervals (spotting\/bleeding between normal flows).<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">General Pathophysiologic Concepts<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Withdrawal Bleeding<\/strong>\n<ul class=\"wp-block-list\">\n<li>Normal cycle: At end of luteal phase, corpus luteum regresses \u2192 drop in estrogen\/progesterone \u2192 endometrial shedding.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Anovulatory Cycles<\/strong>\n<ul class=\"wp-block-list\">\n<li>Persistent estrogen production without ovulation \u2192 endometrium proliferates excessively.<\/li>\n\n\n\n<li>Eventually, random estrogen dips or \u201cbreakthrough bleeding\u201d occur, leading to unpredictable flow.<\/li>\n\n\n\n<li>Common in adolescence, perimenopause, polycystic ovary syndrome (PCOS), weight loss, strenuous exercise, thyroid dysfunction, advanced liver\/renal disease.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Disordered Endometrial Responses<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Mixed proliferative + secretory patterns<\/strong> (e.g., abnormal luteal phases).<\/li>\n\n\n\n<li>Prolonged unopposed estrogen \u2192 endometrial hyperplasia; sporadic estrogen reduction triggers bleeding.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">SPECIFIC CAUSES OF UTERINE BLEEDING<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">1. Non-Uterine Genital Tract Causes<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Ovaries, Fallopian Tubes<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Ovarian cysts\/tumors secreting hormones \u2192 abnormal bleeding.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Cervix, Vagina, Vulva, Urethra, Bladder, Bowel<\/strong>:\n<ul class=\"wp-block-list\">\n<li>Cervical polyps, cervical cancer (often postcoital spotting, not heavy).<\/li>\n\n\n\n<li>Traumas or fistulas from adjacent structures.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">2. Local Uterine Pathologies<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Polyps<\/strong>: Endometrial or cervical polyps.<\/li>\n\n\n\n<li><strong>Leiomyomas (Fibroids)<\/strong>: Benign uterine smooth muscle tumors causing heavy\/prolonged bleeding.<\/li>\n\n\n\n<li><strong>Adenomyosis<\/strong>: Endometrial tissue within the uterine muscle, leading to menorrhagia\/dysmenorrhea.<\/li>\n\n\n\n<li><strong>Uterine Scar Defects<\/strong>: e.g., hysterotomy scar.<\/li>\n\n\n\n<li><strong>Malignancies<\/strong>:\n<ul class=\"wp-block-list\">\n<li><strong>Endometrial adenocarcinoma<\/strong>, <strong>uterine sarcoma<\/strong>, <strong>cervical cancer<\/strong>.<\/li>\n\n\n\n<li><strong>Metastatic<\/strong> disease to endometrium.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Uterine AVM (Arteriovenous Malformation)<\/strong>: Rare cause of profuse bleeding.<\/li>\n\n\n\n<li><strong>Endometritis<\/strong> \/ <strong>PID<\/strong>: Infectious\/inflammatory conditions.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3. Pregnancy-Related<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Placenta Previa<\/strong>, <strong>Abruptio Placentae<\/strong> (premature separation), <strong>Spontaneous\/Induced Abortions<\/strong>.<\/li>\n\n\n\n<li><strong>Ectopic Gestation<\/strong>: Implantation outside uterine cavity can present with bleeding.<\/li>\n\n\n\n<li><strong>Gestational Trophoblastic Disease<\/strong>: e.g., hydatidiform mole, choriocarcinoma.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">4. Systemic Conditions<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Bleeding Diatheses<\/strong>: e.g., von Willebrand disease, factor deficiencies, platelet function disorders.<\/li>\n\n\n\n<li><strong>Coagulopathy<\/strong>: e.g., advanced liver disease, or use of anticoagulants.<\/li>\n\n\n\n<li><strong>Acute Leukemia<\/strong>: Thrombocytopenia \u2192 abnormal uterine bleeding.<\/li>\n\n\n\n<li><strong>Endocrine Disorders<\/strong>: Hypothyroidism, hyperthyroidism, hyperprolactinemia, Cushing syndrome can cause menstrual irregularities.<\/li>\n\n\n\n<li><strong>Chronic Illness<\/strong>: e.g., advanced renal disease associated with anovulation.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">KEY PHYSIOLOGIC PATHWAY<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Normal Cycle<\/strong>\n<ul class=\"wp-block-list\">\n<li>Follicular Phase: Rising estrogen \u2192 endometrial proliferation.<\/li>\n\n\n\n<li>Ovulation (LH surge) ~ day 14 (in a 28-day cycle).<\/li>\n\n\n\n<li>Luteal Phase: Corpus luteum secretes progesterone (and some estrogen) \u2192 secretory changes in endometrium.<\/li>\n\n\n\n<li>No Pregnancy: Hormones \u2193 \u2192 endometrial ischemia \u2192 shedding (menstruation).<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Pathologic Bleeding<\/strong> arises from:\n<ul class=\"wp-block-list\">\n<li><strong>Hormonal Imbalance<\/strong> (e.g., anovulation, unopposed estrogen, suboptimal progesterone).<\/li>\n\n\n\n<li><strong>Uterine Structural Lesions<\/strong> (polyps, fibroids, adenomyosis).<\/li>\n\n\n\n<li><strong>Malignant\/Pre-malignant<\/strong> changes (endometrial hyperplasia, carcinoma).<\/li>\n\n\n\n<li><strong>Pregnancy-Related<\/strong> or <strong>Systemic<\/strong> issues (bleeding disorders, endocrine pathology).<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>INFLUENCE OF GONADAL HORMONES ON THE FEMALE REPRODUCTIVE CYCLE FROM BIRTH TO OLD AGE General Overview INFANCY Newborn Estrogen Effects CHILDHOOD (Postnatal Recess to Pre-Puberty) PUBERTY (Sexual Maturation) ADULT REPRODUCTIVE YEARS Mature Menstrual Cycle (28-day typical example) Additional Changes Pregnancy MENOPAUSE AND SENESCENCE FUNCTIONAL AND PATHOLOGIC CAUSES OF UTERINE BLEEDING Normal Menstrual Bleeding ABNORMAL UTERINE [&hellip;]<\/p>\n","protected":false},"featured_media":0,"template":"","oen_topic_chapter":[685],"class_list":["post-4422459","oen_topic","type-oen_topic","status-publish","hentry","oen_topic_chapter-reproductive-disorders","post-wrapper","thrv_wrapper"],"_links":{"self":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422459","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic"}],"about":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/types\/oen_topic"}],"version-history":[{"count":2,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422459\/revisions"}],"predecessor-version":[{"id":4422462,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic\/4422459\/revisions\/4422462"}],"wp:attachment":[{"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/media?parent=4422459"}],"wp:term":[{"taxonomy":"oen_topic_chapter","embeddable":true,"href":"https:\/\/myendoconsult.com\/learn\/wp-json\/wp\/v2\/oen_topic_chapter?post=4422459"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}