Physiology of Pregnancy

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הההההה הההההה!!!!

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Physiology of Pregnancy. דר' שמואל לוריא מ.ר. וולפסון, חולון. בהצלחה בבחניה!!!!. Genitalia Skin Breasts Metabolic changes Hematologic al Cardiovascular Respiratory. Urinary Gastrointestinal Endocrinology Thyroid Hypermesis Musculoskeletal Eyes CNS. Plan of the lecture. - PowerPoint PPT Presentation

Transcript of Physiology of Pregnancy

בהצלחה בבחניה!!!!

• Genitalia• Skin• Breasts• Metabolic changes• Hematological• Cardiovascular• Respiratory

• Urinary• Gastrointestinal• Endocrinology

– Thyroid

• Hypermesis• Musculoskeletal• Eyes• CNS

Genital tract – uterusGenital tract – uterus

• From 70 gr/10 ml to 1100 gr/5000 ml– Growth 500-1000 times

• Patterns of growth:– Hypertrophy – Fibrous tissue– Vessels, lymphatics– Asymmetrical

• Fundus>other parts• Placental site>other parts

Genital tract – uterusGenital tract – uterus contcont

• Contractility– 1 trimester onwards– Braxton-Hicks (Hicks JB 1823-1899)

• Blood flow– 450-650 ml/min (40W)

– Regulation• Estrogen/Progesterone

• Catecholamines/Angiotensin II

• Nitric oxide (vasodilator)

Genital tract – cervixGenital tract – cervix• Continuous softening

– Increased vascularity– Hypertrophy & hyperplasia of

cervical glands

• Mucus plague obstruction– (Bloody show)

• Squamous Metaplastic Cells– Size, shape, staining– PAP interpretation

Genital tract – vaginaGenital tract – vagina

• Increased vascularity– Violet color – Chadwick sign (1844-1905)

• Wall distention

• Increased thickness of mucosa

Genital tract – ovariesGenital tract – ovaries

• Ovulation ceases during pregnancy.

• Corpus luteum up to 7th week

Genital tract – ovariesGenital tract – ovaries contcont

• Luteoma of pregnancy– Solid ov tumor– Exaggeration of normal lutianization– May be up to 10 cm– Regresses after delivery

SkinSkin

• Pigmentation– Linea nigra

– Chloasma or melasma

– Around areola

– m/p increased MSH

Skin Skin contcont

• Striae gravidarum

• Vascular changes– Palmar erythema– Vascular spiders

BREASTBREAST

• Increased size

• Increased areola size

• Colostrum – 2nd trimester onwards

BREAST BREAST contcont• Increased areola size• Pigmentation• Montgomery

– Pimple like gland

– Secrete lubrication for areola

Metabolic changesMetabolic changes

• Weight gain– Fetus, placenta 4.2– Amniotic fluid 0.8– Uterus 1.0– Breasts 0.4– Blood volume 1.5– 3rd space 1.5– Fat 3.4

• Average 12.5 kg• From 20th week

0.5kg/w

Metabolic changesMetabolic changes

• Recommended daily dietary allowance– 2500 kcal

– 60 gr protein

– Vitamins

– Minerals• Fe, Ca, Mg, Zn, P, I

• Average 12.5 kg• From 20th week

0.5kg/w

Metabolic changes- Metabolic changes- contcont

• Water metabolism– Increased water retention– Fall in plasma osmolality 10mosm/kg– Induced by resetting of thirst and ADH

secretion

Metabolic changes- Metabolic changes- contcont

• Fat metabolism– Increased lipids– Increased lipoproteins– Increased apoliproteins

• Protein metabolism– 1000 gr of protein per total pregnancy

• Fetus, placenta• Uterus• breasts

Metabolic changes- Metabolic changes- contcont

Carbohydrate metabolism• Theology

– Ensure continuous glucose supply to fetus

• Pregnant woman state– Woman’s fuel switch

• Glu > Lipids

– Accelerated starvation

Metabolic changes- Metabolic changes- contcont

Carbohydrate metabolism - cont• Alterations

– Fasting hypoglycemia– Postprandial hyperglycemia– Hyper-insulinemia

• Causes– Increased insulin response to Glu– Reduced peripheral uptake of Glu– Suppressed glucagon response

• Theology– Ensure continuous

glucose supply to fetus

Hematological changesHematological changes

• Blood volume increase 45%– From 1st tr onwards

– Plasma increase 50%

– RBC increase 30%

– Result in “physiologic” anemia

• Why?– To meet demands of enlarged uterus

– To protect mother from impaired venous return

– To safeguard from blood loss due to parturition

Hematological changes – Hematological changes – contcont RBC & HbRBC & Hb

• Elevated erythropoietin – Shorter life span of RBC– Elevated reticulocytes

• “physiologic” anemia:– Normal Hb >11 g/dL– Severe anemia if <10 g/dL

Hematological changes – Hematological changes – contcont RBC & Hb - RBC & Hb - contcont

• Iron– Total iron requirement during pregnancy 1

gr– Daily Iron requirement 7 mg/day

Hematological changes – Hematological changes – contcont

WBC & PltWBC & Plt• WBC

– Increase up to 16,000-20,000– Mainly because of neutrophyls

• Platelets– Plt count decrease, but stay in normal range

• 7% gestational thrombocytopenia– Constant MPV– Constant reticulated plt – Decreased plt activation during pregnancy– Increased plt activation towards delivery

Hematological changes – Hematological changes – contcont

coagulation - coagulation - contcont

• Elevated fibrinogen & factor VIII• Acquired functional resistance to

activated protein C• Decrease in protein S • Antithrombin III levels unchanged

Hematological changes – Hematological changes – contcont

coagulation - coagulation - contcont

• Increased tendency to thrombosis:– Physiologic thrombophilia– Obstruction of venous return by uterus and

venous atonia by progesterone

Cardiovascular systemCardiovascular systemheartheart

• 5th week onward, max 32nd week– Increased cardiac output– Increased heart rate 10 b/min– No change in inotropic effect– Left & upward displacement of apex (ECG)– Increased stroke volume

Cardiovascular systemCardiovascular systemcirculationcirculation

• 5th week onward, max 32nd week– Decreased systemic & pulmonary resistance– Decrease in blood pressure S>D– Supine hypotension syndrome

• Influenced by:– Renin, Angiotensin– PG– Endothgelin

Respiratory systemRespiratory system

• No change in respiratory rate

• Increase in :– Tidal volume

– Minute respiratory volume

– Minute oxygen uptake

Respiratory system- Respiratory system- contcont

• Diaphragm rises ~4 cm

• Unchanged Po2, slightly decreased Pco2

• Physiologic dyspnea (awareness of breathing)

– Tidal volume & lowered Pco2

Urinary systemUrinary system• Increased kidney size by 1.5 cm• Increased GFR & renal plasma flow

– By 50%

– 2nd trimester onwards

• Physiologic gucosuria – Increased GFR

– impaired tubular reabsorptive capacity for Glu

• Physiologic proteinuria– Increased GFR

– Up to 300 mg/24 h collection

Urinary systemUrinary system - -contcont

• Hydronehprosis & hydroureter– Rt > lt in 90% of pregnant women– Cushioning of lt urter by sigmoid colon– Compression of rt ureter by dextrorotated

uterus– Progesterone action

• Bladder– Increase in urinary incontinence

• Progesterone• Uterine pressure

Gastrointestinal tractGastrointestinal tract

• Delayed gastric emptying– Mechanical & hormonal

• Pyrosis – Gastric reflux

• Gestational gingivitis• Constipation• Hemorrhoids

– constipation

Gastrointestinal tractGastrointestinal tractLiver & gallbladderLiver & gallbladder

• Liver– Increased alk phosphat

• Placental

– Other tests unchamged

• Gallbladder– Impaired contraction– Stasis– Increased prevalence of stones

Endocrine systemEndocrine systemthyroidthyroid

• Enlargement of thyroid– Due to increased vascularity

• Increased thyroxin binding globulin– Decreased clearance

• Due to Estrogen

• Total T4 & T3 rise up to 20 w % plateaus but within normal range

• Free T4 & T3 unchanged• Normal TSH within normal range

HHyperemesisyperemesis• Morning sicknessMorning sickness

– 80% up to 14 w80% up to 14 w– Unknown etiologyUnknown etiology

• m/p hormonalm/p hormonal

• HyperemesisHyperemesis• persistent vomiting,persistent vomiting,• dehydration, ketosis,dehydration, ketosis,• electrolyte disturbances,electrolyte disturbances,• weight loss (> 5%)weight loss (> 5%)

– Gastric electrical dysrhythmia Gastric electrical dysrhythmia – Elevated TSHElevated TSH

Musculoskeletal systemMusculoskeletal system

• Lordosis

• Muscular weakness

• Low back pain

EyesEyes

• Decreased intraocular pressure

• Corneal sensitivity

• Krukenberg spindles– Brownish-red pigmentation of posterior

surface of cornea

• Unaffected visual function

CNSCNS

• Problems with:– Concentration

– Attention

– Memory

• Most pregnant women report some memory disturbance

• Decline in :– Explicit memory– Implicit memory– Working memory

Underlying causesof memory impairment

in pregnancy

• Elevated progesterone • Glucocorticoids • Plasma neurotransmitters • Larger erythrocytes

– Lurie S, Piper I, Gordon Y, Reprod Sciences 2005

• Cultural stereotypes

CNS- CNS- contcont

• Mood disturbance– depression– stress – anxiety

• Sleep difficulty– Frequent awakenings– Reduced sleep efficiency