Transcript Physiology of Pregnancy

‫בהצלחה בבחניה!!!!‬
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Genitalia
Skin
Breasts
Metabolic changes
Hematological
Cardiovascular
Respiratory
• Urinary
• Gastrointestinal
• Endocrinology
– Thyroid
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Hypermesis
Musculoskeletal
Eyes
CNS
Genital tract – uterus
• From 70 gr/10 ml to 1100
gr/5000 ml
– Growth 500-1000 times
• Patterns of growth:
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Hypertrophy
Fibrous tissue
Vessels, lymphatics
Asymmetrical
• Fundus>other parts
• Placental site>other parts
Genital tract – uterus cont
• 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 – 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 – vagina
• Increased vascularity
– Violet color
– Chadwick sign (1844-1905)
• Wall distention
• Increased thickness of mucosa
Genital tract – ovaries
• Ovulation ceases
during pregnancy.
• Corpus luteum up to
7th week
Genital tract – ovaries
cont
• Luteoma of pregnancy
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Solid ov tumor
Exaggeration of normal lutianization
May be up to 10 cm
Regresses after delivery
Skin
• Pigmentation
– Linea nigra
– Chloasma or
melasma
– Around areola
– m/p increased
MSH
Skin cont
• Striae gravidarum
• Vascular changes
– Palmar erythema
– Vascular spiders
BREAST
• Increased size
• Increased areola size
• Colostrum
– 2nd trimester onwards
BREAST cont
• Increased areola size
• Pigmentation
• Montgomery
– Pimple like gland
– Secrete lubrication for areola
Metabolic changes
• Average 12.5 kg
• From 20th week
0.5kg/w
• Weight gain
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Fetus, placenta
Amniotic fluid
Uterus
Breasts
Blood volume
3rd space
Fat
4.2
0.8
1.0
0.4
1.5
1.5
3.4
Metabolic changes
• Average 12.5 kg
• From 20th week
0.5kg/w
• Recommended daily
dietary allowance
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2500 kcal
60 gr protein
Vitamins
Minerals
• Fe, Ca, Mg, Zn, P, I
Metabolic changes- cont
• Water metabolism
– Increased water retention
– Fall in plasma osmolality 10mosm/kg
– Induced by resetting of thirst and ADH
secretion
Metabolic changes- cont
• Fat metabolism
– Increased lipids
– Increased lipoproteins
– Increased apoliproteins
• Protein metabolism
– 1000 gr of protein per total pregnancy
• Fetus, placenta
• Uterus
• breasts
Metabolic changes- cont
Carbohydrate metabolism
• Theology
– Ensure continuous glucose supply to
fetus
• Pregnant woman state
– Woman’s fuel switch
• Glu > Lipids
– Accelerated starvation
Metabolic changes- cont
Carbohydrate metabolism - cont
• Alterations
– Fasting hypoglycemia
– Postprandial hyperglycemia
– Hyper-insulinemia
• Theology
– Ensure continuous
glucose supply to
fetus
• Causes
– Increased insulin response to Glu
– Reduced peripheral uptake of Glu
– Suppressed glucagon response
Hematological changes
• Blood volume increase 45%
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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 – cont
RBC & 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 – cont
RBC & Hb - cont
• Iron
– Total iron requirement during pregnancy 1
gr
– Daily Iron requirement 7 mg/day
Hematological changes – cont
WBC & Plt
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WBC
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Increase up to 16,000-20,000
Mainly because of neutrophyls
Platelets
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Plt count decrease, but stay in normal range
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7% gestational thrombocytopenia
Constant MPV
Constant reticulated plt
Decreased plt activation during pregnancy
Increased plt activation towards delivery
Hematological changes – cont
coagulation - cont
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Elevated fibrinogen & factor VIII
Acquired functional resistance to
activated protein C
Decrease in protein S
Antithrombin III levels unchanged
Hematological changes – cont
coagulation - cont
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Increased tendency to thrombosis:
– Physiologic thrombophilia
– Obstruction of venous return by uterus and
venous atonia by progesterone
Cardiovascular system
heart
• 5th week onward, max 32nd week
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Increased cardiac output
Increased heart rate 10 b/min
No change in inotropic effect
Left & upward displacement of apex (ECG)
Increased stroke volume
Cardiovascular system
circulation
• 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 system
• No change in
respiratory rate
• Increase in :
– Tidal volume
– Minute respiratory
volume
– Minute oxygen uptake
Respiratory system- cont
• Diaphragm rises ~4 cm
• Unchanged Po2, slightly decreased Pco2
• Physiologic dyspnea (awareness of
breathing)
– Tidal volume & lowered Pco2
Urinary 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 system -cont
• 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 tract
• Delayed gastric emptying
– Mechanical & hormonal
• Pyrosis
– Gastric reflux
• Gestational gingivitis
• Constipation
• Hemorrhoids
– constipation
Gastrointestinal tract
Liver & gallbladder
• Liver
– Increased alk phosphat
• Placental
– Other tests unchamged
• Gallbladder
– Impaired contraction
– Stasis
– Increased prevalence of stones
Endocrine system
thyroid
• 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
Hyperemesis
• Morning sickness
– 80% up to 14 w
– Unknown etiology
• m/p hormonal
• Hyperemesis
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persistent vomiting,
dehydration, ketosis,
electrolyte disturbances,
weight loss (> 5%)
– Gastric electrical dysrhythmia
– Elevated TSH
Musculoskeletal system
• Lordosis
• Muscular weakness
• Low back pain
Eyes
• Decreased intraocular pressure
• Corneal sensitivity
• Krukenberg spindles
– Brownish-red pigmentation of posterior
surface of cornea
• Unaffected visual function
CNS
• Problems with: • Most pregnant
women
report
some
– Concentration
memory
– Attention
disturbance
– Memory
• Decline in :
– Explicit memory
– Implicit memory
– Working memory
Underlying causes
of memory impairment
in pregnancy
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Elevated progesterone
Glucocorticoids
Plasma neurotransmitters
Larger erythrocytes
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Lurie S, Piper I, Gordon Y, Reprod Sciences 2005
• Cultural stereotypes
CNS- cont
• Mood disturbance
– depression
– stress
– anxiety
• Sleep difficulty
– Frequent awakenings
– Reduced sleep efficiency