PHYSIOLOGIC CHANGES DURING PREGNANCY
Can be categorized as: • Local – reproductive organs only
Ballottement – 16th-20th week,
fetus is small compared to amt of amniotic fluid present. Fetus bounce or rise on tapping sharply the lower uterine segment against the top examining hand
•
Systemic – the entire body is affected
LOCAL CHANGES
A. REPRODUCTIVE SYSTEM CHANGES a. Uterine Changes Length: 6.5 – 32 cm Depth : 2.5 – 22 cm Width: 4 – 24 cm Weight: 50 – 1000g
Braxton-Hicks contraction –
practice contractions, waves of hardness and tightening across her abdomen
b. Amenorrhea Because of FSH suppression
by rising estrogen levels c. Cervical changes
Vascular and edematous –
increased circulating estrogen From pale pink to violet
Thickness: early in pregnancy 1cm-2cm, end of pregnancy 0.5 cm thick
Volume: 2ml – more than 1000ml /4000g at term End of twelfth week palpated at the symphysis pubis
Operculum – mucous plug
in cervical canal that seals out bacteria during pregnancy preventing fetal and membrane infection
20th or 22nd week reached
umbilicus
Goodell’s Sign – softening
of the cervix from elasticity of earlobe to consistency of butter
End of 36th week reached the
xiphoid process ( breathing is difficult)
d. Vaginal changes
38th week, for a primigravida,
fetal head settles into the pelvis, the uterus returns to the height at 36th week
Hypertrophic and enriched
with glycogen – because of increased estrogen light pink to a deep violet : increased vascularity
Chadwick’s sign – normal
o
LIGHTENING – woman’s breathing becomes easier, lightening the load. *In multipara, it occurs at labor
From pH >7 to pH 4 or 5
Uterine blood flow: before 1520 ml/min, by the end of pregnancy 500-750 ml/min *75% goes to placenta
vaginal secretions because of Lactobacillus acidophilus (grows freely in increased glycogen envt) Candida albicans, itching and burning sensation with creamcheese-like discharge
Candidiasis – caused by
Hegar’s sign – extreme
softening of the lower uterine segment, felt as thin as tissue
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Leukorrhea – excessive
discharge e. Ovarian changes
Striae gravidarum – pink
Ovulation stops because of
active feedback mechanism of E & P by corpus luteum/placenta
or reddish streaks on sides of abdomen and on thighs caused by rupture and atrophy of connective layer of skin *weeks after birth becomes striae albicantes or atrophicae (silvery-white)
(-) prodn of FSH and LH
Diastasis – separation of
Corpus luteum – enlarges
until 16th week as placenta takes over as provider of E & P,
rectus muscles, appears after pregnancy as a bluish groove
Umbilicus becomes obliterated and protruding
Then becomes corpus
f. Changes in breasts
albicans – white and smaller
Linea nigra – narrow
brown line in midline
Melasma/chloasma –
6th week. Changes are
noticeable
“mask of pregnancy”, dark pigmentations on cheeks and nose due to MSH spiders/Telangiectases – small, fiery-red, branching spot on thighs due to increasing estrogen
Feeling of fullness, tingling
or tenderness – increased estrogen levels.
Vascular
Increased in size hyperplasia of mammary alveoli and fat deposits Areola darkens and increases in diameter Increased vascularity and prominent blue veins
Activity of sweat glands increases
Palmar erythema –
redness and itching on hands due to estrogen Scalp hair growth increases
Montgomery’s tubercles –
sebaceous glands enlarge and become protuberant - Keeps nipples supple, preventing drying and cracking during lactation
C. RESPIRATORY SYSTEM
Marked congestion or stuffiness of
the nasopharynx – increased estrogen levels diaphragm
Colostrum – thin watery
high-protein fluid that is precursor of breast milk, can be expelled at 16th week
Shortness of breath – pressure on Decreased PCO2 (blood CO2) of
SYSTEMIC CHANGES
32mmHg due to increased progesterone level – easier fetal CO2 transfer to maternal bloodstream
B. INTEGUMENTARY SYSTEM
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Mild Hyperventilation – to
prevent maternal blood pH from becoming acidic bec of CO2 to help, add’l H2O and Na is lost
Decreased iron absorption due to decreased gastric acidity Excessive Fe: stomach irritation
positioning due to diaphragm displacement pregnancy is due to SNS stimulation ; in later months due to increase thoracic pressure
Palpitations: early in
D. TEMPERATURE
Early: increases due to
d. Blood pressure
progesterone due to corpus luteum (same at ovulation) to placenta
1st trimester: BP does not
rise
16th week: decreases to normal due
2nd trimester: BP decreases
due to decreased PR
E. CARDIOVASCULAR SYSTEM
3rd trimester: BP goes up
same with 1st trimester e. Peripheral Blood flow
a. Blood volume – increases by 30%
Blood loss during NSD: 300400 mL Blood loss during CS: 8001000mL
3rd trimester: blood flow in
lower extremities is impaired leading to edema, varicosities of the vulva, rectum, and legs f. Supine Hypotension Syndrome Lying supine, the uterus presses vena cava against vertebrae: obstructing blood flow in lower extremities Decrease venous return: decreased CO and BP
Pseudoanemia - conc. of
hemoglobin and RBC decline in first trimester due to faster plasma volume increase than RBC prod’n b. Iron, Folic Acid & Vitamin Needs
Total increased iron need of
800mg
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Results to: o Maternal: Lightheadedness, faintness and palpitations Fetal: Hypoxia
Heartburn – reflux of
stomach contents into esophagus because of: • upward displacement of the stomach relaxed cardioesophageal sphincter (due to relaxin, enzyme produced by ovaries)
o
Corrected through turning the woman to her left side g. Blood Constitution Fibrinogen: increases by 50% due to increased estrogen level
•
Slow intestinal
peristalsis and the emptying time of stomach due to pressure caused by uterus displacing abdominal organs: leads to heartburn, constipation and flatulence
Clotting Factors VII, VIII, IX,
& X and platelet count increases •
Safeguard against major bleeding
Relaxin: decreases gastric
motility
Total WBC count rises
slightly Total Protein level of blood decreases due to fetal consumption
Progesterone: makes GI
tract less active
Subclinical Jaundice
(generalize itching) • Decreased emptying of bile from the gallbladder: reabsorption of bilirubin in maternal bloodstream
Ankle & foot edema is
common due to lower total protein load and hypovolemia: equal osmotic and hydrostatic pressure 1/3*
Blood lipids increases by Cholesterol serum levels
increases by 90-100%* *for ready supply of available energy to the fetus
Hypertrohy of gumlines
& bleeding of gingival tissue saliva prod’n due to increased estrogen lvls
Hyperptyalism – increased
Increased tooth decay:
lower than normal pH of saliva
F. GASTROINTESTINAL SYSTEM
First trimester: “Morning
sickness” - nausea and vomiting early in the morning, increased HCG and progesterone levels/increased estrogen and decreased glucose
G. URINARY SYSTEM • Changes results from: o o Effects of high E & P levels Compression of bladder and ureters
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o o
Increased blood volume Postural influences
c. Bladder and ureter function
Polyuria – increase urinary
frequency, during 1st trimester Until uterus rises out of pelvis and relieves pressure on bladder. This returns as lightening occurs. Ureters increased in diameter & bladder capacity increases to 1500ml: due to increased progesterone
a. Fluid retention
Total Body H2O increases to
7.5 L: increase Na reabsorption
Increased Aldosterone
prod’n due to increased response Angiotensin-renin system to progesterone
o
Aldosterone aids in Na reabsorption
Uterus rises on the right
K levels remain adequate due to progesterone
side, pushed slightly by sigmoid colon: pressure on right ureter
H2O is retained: aid the
increase in BV and serve as ready fluid supply of fetus
o
If not relieved, urinary stasis and pyelonephritis
b. Renal Function Kidneys increased in size Urine output increases 6080% Sp. Gr. Decreases GFR and renal plasma flow increases early in pregnancy At 2nd trimester, they increased by 30-50% Lower BUN and creatinine lvls o 15mg/100ml or higher BUN is abnormal, as well as, Greater than 1mg/100ml creatinine
Pressure on urethra: poor bladder emptying and bladder infection
o
Leads to kidney infection (mother) and UTI (fetus)
H. SKELETAL SYSTEM Ca and P need is increased o Fetal skeleton must be build
Gradual softening of pelvic ligaments and joints (relaxin and progesterone) Excessive mobility of joints causes discomfort 3mm-4mm separation of symphysis pubis at 32 weeks o Difficulty walking
o
Gestational DM due to:
o Accidental spilling of glucose in urine due to reabsorption of glucose Unused lactose is also spilled
Lordosis/ “Pride of
o
Pregnancy” – forward curve of lumbar spine, may lead to backache
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I.
ENDOCRINE SYSTEM a. Placenta Produces large amts of E, P, HCG, HPL, relaxin & prostaglandins
Increased lvls of: protein-bound iodine, butanol-extractable iodine and thyroxine
Emotional lability, tachycardia, palpitations, and diaphoresis
ESTROGEN causes: breast and uterine enlargement, & palmar erythema PROGESTERONE is involved in: maintenance of endometrium, inhibition of uterine contractility, & development of breasts for lactation RELAXIN (corpus luteum): helps in inhibiting uterine activity, softening of the cervix (dilatation at birth) and collagen in joints (laxness in the lower spine & enlargement of birth canal) HCG (trophoblast): stimulates E and P synthesis HPL: insulin antagonist; more glucose for fetus PROSTAGLANDIN: affect smooth muscle contractility, initiates labor
Parathyroid also increases in size, calcium prod’n
d. Adrenal glands Increased corticosteroids & aldosterone due to increased AG activity
e. Pancreas Increased insulin prod’n due to increased glucocorticoid lvls Maternal blood glucose level > fetal glucose level o To prevent hypoglycemia: Increase MBGL than normal Low FBS of mother during first trimester Less effective insulin due to insulin-antagonists (E, P & HPL)
b. Pituitary Gland (-) prod’n of FSH and LH due to increased P and E Increased prod’n of GH and MSH Later: prod’n of oxytocin and prolactin J. IMMUNE SYSTEM
c. Thyroid and Parathyroid Glands
Thyroid enlarges: BMR increases by 20%