Physiologic changes during pregnancy - PowerPoint PPT Presentation

Loading...

PPT – Physiologic changes during pregnancy PowerPoint presentation | free to view - id: 418bbf-MTVlM



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Physiologic changes during pregnancy

Description:

Physiologic changes during pregnancy ... and interpretations during physiological changes Organ systems Cardiovascular system Pulmonary system Genital tract ... – PowerPoint PPT presentation

Number of Views:362
Avg rating:3.0/5.0
Slides: 41
Provided by: NancyT78
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Physiologic changes during pregnancy


1
Physiologic changes during pregnancy
2
Objectives
  • Symptoms and physical findings of each organ
    system
  • Physiologic versus pathologic changes
  • Diagnostic tests and interpretations during
    physiological changes

3
Organ systems
  • Cardiovascular system
  • Pulmonary system
  • Genital tract
  • Urinary system
  • Endocrine system
  • Gastrointestinal Tract
  • Skin

4
Cardiovascular system
  • Total Body water
  • Cardiac Output

5
Total body water
  • Increases 6-8 L
  • Increases by 40
  • Normal body water
  • 2/3 intracellular
  • 1/3 extracellular
  • ¾ interstitial
  • ¼ intravasular
  • 2/3 increase is extravascular

6
Physiologic anemia of pregnancy
  • Physiologic intravascular change
  • Plasma volume increases 50-70
  • Beginning by the 6th wk
  • RBC mass increases 20-35
  • Beginning by the 12th wk
  • Disproportionate increase in plasma volume over
    RBC volume----Hemodilution
  • Despite erythrocyte production there is a
    physiologic fall in the hemoglobin and hematocrit
    readings

7
Patients without overt anemia not given
supplementation
concentration Non preg 1st Tri 2nd Tri 3rd Tri deliv
HB 13.0 12.2 10.9 11.0 12.4
Serum iron 90.0 106.5 75.3 56.0 57.1
Serum Ferritin 63.0 97.4 22.2 14.7 27.6
  • Wide standard deviation

Williams 21ed
8
Iron deficiency anemia
  • With erythropoiesis of pregnancy, iron
    requirements increase.
  • Because large amounts of iron may not be
    available from body stores and may not be in the
    diet
  • Supplementation is recommended to prevent iron
    deficiency anemia
  • At term, Hemoglobin less than 10.0 is usually due
    to iron deficiency anemia rather than the
    hemodilution of pregnancy

9
Normal Iron Requirements
  • Total body iron content average in normal adult
    females is 2gm
  • Iron requirement for normal pregnancy is 1 gm
  • 200 mg is excreted
  • 300 mg is transferred to fetus
  • 500 mg is need for mom
  • Total volume of RBC inc is 450 ml
  • 1 ml of RBCs contains 1.1 mg of iron
  • 450 ml X 1.1 mg/ml 500 mg
  • Daily average is 6-7 mg/day
  • Small intervals between pregnancies are most
    concerning

10
Cardiovascular system
  • Total Body water
  • Cardiac Output

11
Cardiac output (COHR X SV)
  • Begins to increase by the 5th wk
  • Rise of 40 by 20-24 wks
  • Initial increase is a function of
  • The increase in heart rate
  • Reduced systemic vascular resistance
  • By 10- 20 wks the increase in CO is reflected
    mainly by the increase in SV
  • The notable increase in plasma volume or preload
    contributes to the increase SV
  • As pregnancy advances to term, the HR continues
    to increase but the SV falls to close to normal
    levels, this accounts for the fall in CO to near
    non-pregnant levels at term

12
Interpretation of tests during pregnancy
  • CXR
  • Elevation of diaphragm
  • Heart to be displaced to the left and upward
  • Increase in the cardiac silhouette
  • benign pericardial effusion
  • Echocardiogram
  • Increased left ventricular wall mass
  • Increased end diastolic dimensions
  • Increase in EDV and therefore inc in SV
  • Electrocardiogram
  • Slight left axis deviation

13
Respiratory system
  • Mechanical
  • diaphragm
  • Consumption
  • Increase in needed oxygen
  • Stimulation
  • Progesterone stimulation

14
Respiratory
  • Mechanical
  • Diaphragm rises 4 cm
  • Less negative intrathoracic pressure
  • Dec FRC-Functional Residual Capacity
  • volume after passive expiration
  • Dec ERV-Expiratory Reserve Volume
  • max volume expired after expiration
  • Dec RV-Residual Volume
  • volume after max expiration
  • No impairments in diaphragmatic or thoracic
    muscle motion
  • Lung compliance remains unaffected

15
Respiratory
  • Consumption
  • O2 consumption Increases 15-20
  • 50 of this increase is required by the uterus
  • Despite increase in oxygen requirements, with the
    increase in Cardiac Output and increase in
    alveolar ventilation oxygen consumption exceeds
    the requirements.
  • Therefore, arteriovenous oxygen difference falls
    and arterial PCO2 falls.

16
Respiratory
  • Stimulation
  • Progesterone is known to directly stimulate
    ventilation
  • Progesterone increases the sensitivity of the
    respiratory centers to CO2
  • Also, it is thought to reduce total pulmonary
    resistance

17
Respiratory
  • Minute ventilation RR X Tidal volume
  • Tidal Volume-increases
  • Volume of air Inspired and expired with each
    breath
  • Minute ventilation-increases
  • Volume inspired or expired in 1 min
  • RR- remains unchanged
  • Vital capacity-remains unchanged
  • Max volume that can be forcibly inspired after
    max expiration

18
Physiologic changes
  • Dyspnea-increase in desire to breathe
  • 70 of pregnant women experience this
  • Occurs during 1st trimester without mechanical
    factors
  • No change on PFTs
  • The lower PCO2 then paradoxically causes dyspnea
  • The marked change or marked decline in PCO2
    results in the sensation of dyspnea

19
Genital Tract
  • Increased vascularity and hyperemia
  • Vagina
  • Perineum
  • Vulva
  • Increased secretions
  • Characteristic violet color of the vagina
  • Chadwicks sign
  • Increased length to the vaginal wall
  • Hypertrophy of the papillae of the vaginal mucosa

20
Genital Tract
  • Uterine hypertrophy of the myocytes
  • Hypertrophy can cause venous compression
  • Can result in fall in venous return
  • Furthermore a fall in CO
  • Physiologic compensation
  • Rise in peripheral resistance to minimize fall in
    blood pressure

21
Genital Tract
  • Without Physiologic compensation
  • Supine hypotensive syndrome can occur with a
    gravid uterus
  • Symptoms-Nausea, dizziness, syncope
  • Can be relieved with position changes

22
Gravid uterus has limited autoregulation
  • Uterine blood flow is Increased 100 ml/min to
    1200 ml/min
  • Because uterine vessels are maximally dilated
    little autoregulation can occur to improve flow
    during perfusion pressure changes
  • When maternal Cardiac output declines, blood flow
    is shifted away from the uteroplacental
    circulation to the maternal brain, kidney and
    heart.

23
Urinary System-Dilation
  • Calyces, renal pelves, and ureters undergo marked
    dilatation
  • More prominent on the right
  • Partial obstruction of the ureters can occur at
    the pelvic brim
  • Progesterone produces smooth muscle relaxation
    which is thought to cause the relaxation noted

24
Urinary System-inc GFR
  • GFR and renal plasma flow increases 40 by
    mid-gestation
  • Plateaus, then remains unchanged until term
  • Elevated GFR is reflected in the lower serum
    levels of creatinine and blood urea nitrogen
  • NL GFR 120-160 ml/min

25
Urinary System-Proteinuria
  • Normally not evident
  • Average is 115 mg/day
  • 260 mg/day is in 95 percent confidence limit
  • Therefore, our 300 mg screen would exceed most
    normal variations

26
Endocrine
  • Normal pregnancy physiology shows
  • lower lows and higher highs
  • Postprandial hyperglycemia
  • To ensure sustained glucose levels for fetus
  • Accelerated starvation
  • Early switch from glucose to lipids for fuels
  • Insulin resistance promotes hyperglycemia
  • Resistance-Reduced peripheral uptake of glucose
    for a given dose of insulin
  • Mild fasting hypoglycemia occurs with elevated
    FFA, triglycerides,and cholesterol

27
Insulin resistance
  • Anti-insulin environment is aided by
  • placental lactogen
  • Like growth hormone
  • Increases lipolysis and FFA
  • Increases tissue resistance to insulin
  • Increased unbound cortisol
  • Estrogen and Progesterone may also exert some
    anti-insulin effects

28
Thyroid
  • Estrogen stimulates Increase in TBG
  • Total T3 and T4 are increased
  • However the active hormones remains unchanged
  • hCG stimulates thyroid
  • TSH is reduced
  • Iodine deficient state
  • Due to Increased renal clearance
  • To rule out pathologic changes
  • Early in pregnancy TSH can be used
  • Later free T4 is needed

29
Gastrointestinal Tract
  • Displacement of the stomach and intestines
  • Appendix can be displaced to reach the right
    flank
  • Gastric emptying and intestinal transit times are
    delayed secondary to hormonal and mechanical
    factors
  • Pyrosis is common due to the reflux of secretions
  • Vascular swelling of the gums
  • Hemorrhoids due to elevated pressure in veins

30
Liver
  • Liver morphology unchanged
  • Lab Tests similar to liver disease
  • Alkaline phosphatase doubles
  • AST, ALT, GGT and bilirubin are slightly lower
  • Decreased plasma albumin

31
Gallbladder
  • Impaired contraction
  • High residual volumes
  • Promotion of stasis
  • Stasis associated with increased cholesterol
    saturation of pregnancy, supports predisposition
    of stones
  • Intrahepatic cholestasis
  • Retained bile salts-pruritus gravidarum

32
Skin changes
  • Chloasma or melasma gravidarum
  • Striae
  • Linea nigra

33
Melasma
34
Melasma
35
Melasma
  • Also known as the mask of pregnancy
  • More common in dark skin people
  • More pronounced in the summer
  • Fades a few months after delivery
  • Repeated pregnancy can intensify
  • Can occur in normal non-pregnant women with
    harmless hormonal imbalances or women on OCPs or
    depo

36
Striae

37
Striae
  • Reddish slightly depressed
  • Breasts, thighs, and abdomen
  • In future pregnancies they appear as glistening,
    silver lines

38
Linea nigra

39
Hyperpigmentation
  • Melasma and linea nigra
  • Estrogen and progesterone
  • Some melanocyte stimulating effect

40
The End
About PowerShow.com