PHYSIOLOGICAL AND
PSYCHOLOGICAL CHANGES OF
PREGNANCY
DEBBIE AMASON,RN,MS
SPRING 2001
Changes
affect both parents
 physiologic
 psychological
 temporary
 “state of wellness”

Diagnosis
feelings can be good or bad
 confirmation
 early diagnosis important

Presumptive Signs

can be caused by other
problems
•
•
•
•
•
•
amenorrhea
nausea and vomiting
fatigue
urinary frequency
breast tenderness
quickening
Probable Signs

changes in the pelvic organs
• Goodell’s Sign
• Chadwick’s Sign
• Hegar’s Sign
Increase in size of uterus
 Ballottement
 Braxton-Hicks contractions
 Serum lab tests

Positive Signs

fetal heart rate

fetal movement felt by examiner

visualization by ultrasound
Physiological Changes

local- reproductive

systemic- major body organs
Local

Uterus
• pre-pregnancy small semisolid
pear shaped
• weight increases from 50Gm to
1000Gm
• enlargement primarily a result of
hypertrophy of pre-existing
myometrial cells
Uterine
development of new fibroelastic tissue between bands of
muscles
 cells increase as result of
estrogen
 measure
 lightening

Uterine
blood flow 15-20ml/min prepregnancy
 at term 500-700ml/min
 by end of pregnancy 1/6 total
maternal blood volume is
circulating through the uterus
 bleeding- serious problem

Uterus

Braxton Hicks
•
•
•
•
•
•

painless contractions
estrogen
distention of the uterus
felt by 4th month
“practicing”
no cervical changes occur
amenorrhea
Cervix

mucosa of cervix undergoes
marked changes
• endocervical cells secrete thick,
tenacious mucus which
accumulates and forms the mucus
plug.
• Seals the cervical canal to prevent
infection
• expelled at start of labor
Cervix
increased
increased
 increased
increased

mucus leads to
discharge
vascularity and
discoloration
Vagina
epithelium undergoes
hypertrophy and hyperplasia
 estrogen

• secretions are acidic> increased
growth of Candida

at term vaginal walls are
relaxed
Ovaries

cease ovum production related
to active feedback mechanism
of estrogen and progesterone
produced by the corpus luteum
and the placenta
Breasts
changes are noted soon after
first missed period
 increase in size and nodularity
 preparing for lactation
 2nd month superficial veins are
prominent
 nipples are more erect

Breasts
pigmentationof areola is more
prominent
 sebacious glands enlarge
(Montgomery Tubercles)
 16th week colostrum

Integumentary System
nipples and areola areas of
breasts are darker
 striae gravidarum
 linea nigra
 chloasma
 diastasis rectus

Respiratory
tidal volume increases 40%
 respiratory rate increases

• small degree of hyperventilation
oxygen consumption increases
by 20%
 diaphragm is displaced >SOB
 no change in vital capacity

Respiratory

Progesterone levels signal
hypothalmus to reset
acceptable PCO2 levels
• low CO2 levels allows for CO2 to
cross the placenta
• maintain pH with load of CO2 from
fetus- mother hyperventilates to
blow off excess
Respiratory

cumulative effect
• SOB
• nasal stuffiness
• epistaxsis
Cardiovascular
pressure on diaphragm
displaces the heart
 blood volume increases 30-50%

• occurs gradually and peaks at 2832 weeks
• adequate exchange of nutrients
• compensate for blood loss
CV

rise in cardiac output 25-50%
• pulse rate increases
• BP remains relatively unchanged

concentration of Hgb and
erythrocytes may initially
decline
CV

femoral venous pressure slowly
rises
• stasis
• dependent edema
• varicosities

fibrinogen levels increase 50%
• clotting factors
• platelets

wbc, protein
GI

nausea and vomiting associated
with HCG
•
•
•
•
•
50% affected
peculiarities of taste and smell
intestines are displaced
heartburn
constipation
GI
hemorrhoids
 acidity of stomach decreases
 hypertrophy of gums and
gingival bleeding

Urinary

alterations
• fluid retention,renal, ureter, and
bladder function

result of:
• estrogen and progesterone
activity
• compression
• increased blood volume
• postural influences
Urinary
total body H2O content
increases
 must increase Na reabsorption
 retained to assist:

• increased blood volume
• source of nutrients for the fetus
Urinary
excrete waste from mother and
fetus
 breakdown protein
 compensate for blood volume
 UOP increases 60-80%
 specific gravity decreases

Urinary

GFR increases
• decrease BUN
• increase filtration of glucose
ureters increase in diameter
 bladder capacity increases
 frequency increases (1012X/day)

Skeletal
no obvious changes in teeth
noted
 joints of pelvis relax r/t hormone
relaxin

• waddle
• shift in center of gravity
Endocrine

placenta produces:
•
•
•
•
•
•
estrogen
progesterone
HCG
HPL
relaxin
prostaglandins
Endocrine

thyroid
•
•
•
•
increased vascularity
hyperplasia
increased BMR
increased oxygen consumption
Endocrine

pituitary
• decreased FSH and LH
• Prolactin increases
• secretes oxytocin

results in:
• anovulation
• lactation
• increased pigmentation
Endocrine

pancreas- early pregnancy
• there is a decrease in insulin
production r/t increased fetal
demands

after 1st trimester
• increase in insulin production r/t
insulin antagonist properties of
estrogen, progesterone, and HPL
Psychological

attitudes depends on:
•
•
•
•
•

environment
social
cultural
family
individuals
gamut of emotions
• need time to adjust
First Trimester

Developmental Task
•
•
•
•
acceptance of pregnancy
50% are surprises
concerns center on self
partners response
Second trimester

Acceptance of Baby
•
•
•
•
quickening
start to make plans
educate
fantasize
Third Trimester

Preparing for Parenthood
•
•
•
•
•
nesting
must complete specific tasks
reworking developmental tasks
role playing
fantasizing
Emotional Responses
ambivalence
 grief
 narcissism
 introversion vs. extroversion
 body image and boundary
 stress
 couvade syndrome

Responses
emotional lability
 change in sexual desire
 change in expectant family
