Physiological changes in pregnancy. It includes changes in the genital organs, uterus, cardiovascular changes, respiratory, metabolic, alimentary, skin, skeleton, psychological changes, urinary changes and weight gain in pregnancy.

1. PHYSIOLOGICAL CHANGES
IN PREGNANCY
PREPARED BY:
Ms. NIKITA SHARMA
NURSING TUTOR
BEE ENN CON, JAMMU.

2. GENITAL ORGANS
• Edematous
• More vascular
• Superficial viscosities
(multipara)
• Labia minora are
pigmented &
hypertrophied.
VULVA

3. GENITAL ORGANS
• Wall becomes hypertrophied
• Edematous & more vascular
• Increased blood supply to
the venous plexus
surrounding the walls gives
bluish discoloration of the
mucosa(Jacquemier’s sign)
VAGINA

4. GENITAL ORGANS
Secretions of vagina:
 Copious, thin, curdy white d/t marked exfoliated cells and
bacteria
pH becomes acidic (3.5-6) due to more conversion of glycogen in
to lactic acid by the Lactobacillus acidophilus consequent on high
estrogen level.
The acidic pH prevents multiplication of pathogenic organisms.
Cytology
Navicular cells in cluster & plenty of lactobacillus

5. UTERUS
Non Pregnant Uterus Pregnant Uterus
Muscular
Structure
Almost Solid Relatively thin – walled (≤
1.5 cm)
weight ≈ 60 gm At term :900-1000 gm
Volume 5-10 mL ≈ 5 L by the end of
pregnancy
Length 7.5cm 35cm

6. BODY OF THE UTERUS
CHANGES IN THE MUSCLES
• Hypertrophy & hyperplasia (12weeks)
• Stretching (20 weeks)
• Wall become thin (1.5cm or less)
• Uterus feels soft and elastic in contrast to firm feel of the non-
gravid uterus.

7. BODY OF THE UTERUS
Arrangement of muscle fibres
- Outer longitudinal
-Inner circular
- Intermediate crisscross
- Living ligatures

8. UTERINE MUSCLES

9. LIVING LIGATURES

10. CONTINUE…..

11. BODY OF THE UTERUS
Vascular system
- Uterine and ovarian arteries
-Marked spiraling of arteries (max. 20weeks) after that
straighten out
-vasodilation is due to estradiol and progesterone.
- Vascular changes are more pronounced at placental site
-uterine enlargement is not symmetrical (fundus enlarges >
body)

12. SHAPE OF THE UTERUS
State Shape
Non-pregnant pyriform
12 weeks Globular
28 weeks ovoid
Beyond 36 weeks Spherical

13. UTERINE GROWTH

14. POSITION OF THE UTERUS

15. BRAXTON- HICKS
CONTRACTIONS
 Irregular
Infrequent
Spasmodic
Painless
Intrauterine pressure remains below 8mmHg.
In abdominal pregnancy, these are not felt.
Without any effect on the
dilatation of the cervix

16. BRAXTON- HICKS
CONTRACTIONS
 During contraction, there is complete closure of uterine veins
with partial occlusion of the arteries in relation to intervillous
space resulting in stagnation of blood in the space.
 This diminishes the placental perfusion, causing transient fetal
hypoxia which leads to fetal bradycardia coinciding with the
contraction.

17. CTG INTERPRETATION

18. DECIDUA

19. CHANGES IN THE ENDOMETRIUM

20. ISTHMUS
1st
trimester
• Hypertrophy
• Elongates to 3 times
• softer
More than
12 weeks
• Unfolds fro above, downward until it is incorporated into
uterine cavity.
• Circulatory muscle fibres acts as sphincter and retain the
fetus into uterus

21. ISTHMUS

22. ISTHMUS INCOMPETENCE
Mid trimester
abortion
Encirclage
operation

23. CERVIX
Stroma *Hypertrophy
*Hyperplasia
*Fluid
accumulation
*Increased
vascularity
GOODELL’S
SIGN (6weeks)
Epithelium
Proliferation of
endocervix mucosa
beyond SCJ
CIN
Secretions Tencious mucous
Physiological
leucorrhea of
pregnancy
Due to
progesterone effect
Helps in Sealing
cervical canal
d/t
estrogen
effect
• Immunogl-
obulins
• cytokines

24. CERVICAL CHANGES

25. FALLOPIAN TUBE
 Increased in length
Become congested
Hypertrophy of muscles
Epithelium become flattened
Patches of Decidual reaction
Due to progesterone effect; during implantation there is structural and secretory
changes in decidua

26. OVARY
Increase growth & function of CORPUS LUTEUM
D/t the influence of oestrogen and progesterone maintenance of decidua (ovarian &
-menstrual cycle suspension)
Ovaries become 2.5 cm long
 Becomes cystic
 Color changes- Bright orange yellow pale
Regression occurs following decline in the secretion of hCG from the placenta.

27. BREASTS
size
Increased
Hypertrophy & proliferation of
ducts (oestrogen) & alveoli
(oestrogen & progesterone)
Increased vascularity leads to
visibility of bluish veins under skin
Axillary tale becomes enlarged &
painful

28. BREASTS
NIPPLES & AREOLA
*Larger
*Erectile
*Deeply
pigmented
* Montgomery’s
tubercles
* In 2nd
trimester ;
appearance of
secondary
areola
- 5-15 in no.
- Sebcious glands
hypertrophy which
remain hide in non-
preg. State
- Makes moist &
healthy

29. SECRETIONS OF BREAST
Colostrum (12th
week)
Thick &
yellowish
(16th week)

30. CUTANEOUS CHANGES
PIGMENTATION
CHLOASMA
GRAVIDARUM

31. PIGMENTATION IN ABDOMEN
STRAE ALBICANS
STRIAE
GRAVIDARUM
LINEA NIGRA

32. OTHER CUTANEOUS
CHANGES
Palmer erythema Vascular spider
Mild hirsutism

33. Excessive hair loss
In puerperium
OTHER CUTANEOUS
CHANGES

34. WEIGHT GAIN
 Total weight gain in pregnancy = 11kg (24 lb)
 1st trimester = 1 kg
2nd trimester = 5kg
3rd trimester = 5kg
 Total weight gain at term
• Reproductive weight gain = 6kg (fetus, placenta, liquor, uterus, breast,
fat+protein)
• Net maternal weight gain = 6 kg (increase in blood volume = 1.3kg &
extracellular fluid =1.2kg)

35. WEIGHT GAIN
Due to increase in
estrogen,
progesterone and
ADH hormones
Fluid retention
-Sodium=
1000mEq
- Potassium = 10g
- Chlorides
At term = 6.5 L
sodium retention

36. IMPORTANCE OF WEIGHT
GAIN
 To detect abnormality
 to detect underweight & overweight conditions
Careful supervision in those cases in which weight gain occurs
> 0.5kg (1lb)/ week or >2kg (5lb)/ month in later month of
pregnancy ( pre-eclampsia)
 to detect stationary & falling weight ( IUGR or IUD)

37. NORMAL WEIGHT GAIN
Condition BMI Weight gain
Normal 20-26 11-16 kg
Obese >29 Not >7kg
Underweight <19 18kg

38. CARDIOVASCULAR SYSTEM
ANATOMICAL CHANGES
Elevation of diaphragm
Heart pushed upward & outward with slight rotation of left.
 Abnormal clinical findings: palpitations, increased pulse
rate with extra systole, systolic murmur in apical &
pulmonary area d/t increased blood viscosity & torsion of
great vessels.
Normal ECG

39. CARDIOVASCULAR SYSTEM
CARDIAC OUTPUT
 starts to increase from 5th week of pregnancy
Peak (40-50%) at about 30-34 weeks & remains static
till term ( left recumbant position)
 CO low in sitting or supine position whereas highest
in Rt., Lt. lateral or knee chest position.
CO increases 50% during labour & 70% immediately
following delivery (Auto transfusion)

40. CARDIOVASCULAR SYSTEM
 CO becomes normal 1 hour following delivery
 It becomes as pre pregnant state at 4 weeks of puerperium.
Increase in CO is due to:
 Increase in blood volume
Additional oxygen demand
 BP = decreases

41. CARDIOVASCULAR SYSTEM
VENOUS PRESSURE
 Antecubital venous pressure – unaffected
 Femoral venous pressure - increases in later months(8-10cm of
H2O)
 Lying position = 25 cm of H2O
Standing position = 80-100 cm of H2O d/t pressure by gravid
uterus on common iliac veins.
 physiological edema subsides on rest

42. CARDIOVASCULAR SYSTEM
 Stagnation of blood in venous system + distensibility of vein
Oedema, varicose vein, piles and DVT
 Supine Hypotension Syndrome: Late pregnancy
compression effect on inferior vena cava by gravid uterus
In supine position, opening of collateral circulation
If it fails to open up decrease venous return to heart syncope, hypotension and
tachycardia

43. BREAST CHANGES

44. RESPIRATORY SYSTEM
Enlargement of
uterus
Elevation of
diaphragm by 4 cm
Total lung capacity
is reduced by 5 %
Diaphragmatic
breathing
Hyperventilation

45. RESPIRATORY SYSTEM
d/t progesterone effect
Hyperventilation
Increase in tidal volume &
respiratory minute volume by 40%
Increase sensitivity of Centre to
carbon dioxide
Dyspnea

46. RESPIRATORY SYSTEM
 Subcostal angle changes from 68 degree to 103 degree
Transverse diameter of chest increased by 2 cm
Chest circumference increased by 5-7 cm
Mucosa of nasopharynx become hyperemic and edematous
Nasal stuffiness & epistaxis (rare)

47. RESPIRATORY SYSTEM
Acid-base balance
Hyperventilation changes acid-base
balance
Arterial PaCO2 decreases from 38 to 32 mmHg
PaO2 increases from 95 to 105 mm Hg
Transfer of CO2 from fetus to mother
and oxygen from mother to fetus.

48. RESPIRATORY SYSTEM
• pH increases in order to 0.02 units and base excess by 2mEq/L
pregnancy is a state of Respiratory Alkalosis
Renal compensation by increased excretion of bicarbonates
 Maternal oxygen consumption is increased by 20-40% due to
increased demand.

49. ALIMENTARY SYSTEM
Gums
Congested
Spongy
Bleed to
touch

50. ALIMENTARY SYSTEM
 Muscle tone & motility of entire GIT is decreased
(progesterone effect)
Relaxed cardiac sphincter
Regurgitation of acid gastric content into esophagus
Chemical esophagitis & heart burn

51. ALIMENTARY SYSTEM
 There may be diminished gastric secretion and delayed
emptying time of stomach.
Decreased risk of peptic ulcer disease
 Atonicity of gut Constipation
 Diminished peristalsis more absorption of food
materials

52. ALIMENTARY SYSTEM
LIVER
• No histological changes
• Depressed function except alkaline phosphatase, other
liver function test ( serum level of bilirubin, AST, ALT,
CPK, LDH) remain unchanged.
GALL
BLADDER
• Mild cholestasis ( estrogen effect)
• Marked Atonicity of gall bladder (Progesterone effect)
• Together with high cholesterol level during pregnancy
favors Stone Formation.

53. URINARY SYSTEM
• Dilatation of ureter, renal pelvis &
calyces
• Enlarges in length by 1cm
• Plasma flow increases by 50-70%
(16week & maintain until 34 weeks
thereafter it falls by 25%)
• GFR is increased by 50% leads to
reduction in maternal plasma, levels of
creatinine, blood urea, BUN & uric
acid.
• Renal tubules fails to reabsorb
glucose, uric acid, amino acids, water
soluble vitamins and other substance
completely.
KIDNEY

54. URINARY SYSTEM
• Atonic d/t high progesterone
effect
• Dilatation of ureter above the
pelvic brim with stasis is marked
on the right side d/t dextrorotation
of the uterus
• Stasis is marked between 20-24
weeks
• Marked hypertrophy of muscles
and sheath of ureter d/t estrogen
• Kinking, elongation and outward
displacement of ureters.
URETER

55. URINARY SYSTEM
• Marked congestion with hypertrophy of
muscles and elastic tissues of the wall.
• In late pregnancy, its mucosa becomes
edematous following early engagement
• Increased frequency of micturition is
noticed at 6-8 weeks & subsides after 12
weeks & in late pregnancy it reappears
d/t resettling of osmoregulation causing
increased water intake and polyuria.
BLADDER

56. URINARY SYSTEM
 Stress incontinence may be observed in late pregnancy due to
urethral sphincter weakness.

57. METABOLIC CHANGES
(GENERAL)
Total metabolism is increased d/t the
needs of growing fetus & the uterus
Basal metabolic rate is increased up
to an extent of 30% higher than that
of average for the non- pregnant
women.

58. METABOLIC CHANGES
• Positive nitrogenous balance throughout the
pregnancy
• Breakdown of the amino acid to urea is suppressed,
blood urea level falls to 15-20mg%
• Amino acids are actively transported across the
placenta to the fetus
• Pregnancy is an Anabolic state.
(PROTEIN METABOLISM)

59. (CARBOHYDRATE METABOLISM)
Transfer of
more
glucose
• Increase
d insulin
secretion
• Hypertroph
y and
hyperplasia
of beta cells
of pancreas
Decreased(44%)
Sensitivity of
insulin receptors
• Increased new
plasma levels
d/t no. of
contra insulin
factors.
These are:
Estrogen,
progesterone,
HPL, cortisol,
prolactin, free
fatty acids
• Tissue
resistance to
insulin.
This mechanism ensures continues supply of glucose to the fetus

60. (CARBOHYDRATE METABOLISM)
Increased insulin levels favors Lipogenesis (Fat storage)
 During maternal fasting; there is hypoglycemia,
hypoinsulinemia, hyperlipidemia and hyperketonemia
 lipolysis generates fatty acids for gluconeogenesis and fuel
supply.
Plasma glucagon level remains unchanged.
Overall effect is maternal fasting hypoglycemia (d/t fetal
consumption), postprandial hyperglycemia & hyperinsulinemia
(d/t insulin factors)

61. (CARBOHYDRATE METABOLISM)
 Oral Glucose Tolerance Test (OGTT) may show an abnormal
pattern.
 This helps to maintain continuous supply of glucose to the
fetus.
As maternal utilization of glucose is reduced, there is
gluconeogenesis and glucogenolysis.
Glomerular filtration of the glucose is increased to exceed the
tubular absorption threshold(normal 180%). So, glycosuria is
detected in 50% of normal pregnant women.

62. (FAT METABOLISM)
Average of 3-4 kg of fat stored during
pregnancy mostly in the abdominal wall,
breasts, hips and thighs.
Plasma lipids & lipoproteins increase
appreciably during the later half of the
pregnancy due to increased estrogen,
progesterone, hPL and leptin levels.

63. (LIPID METABOLISM)
HDL level is increased by 15%
LDL is utilized for placental steroid
synthesis. This hyperlipidemia of normal
pregnancy is non- atherogenic.
*Activity of lipoprotein lipase is increased
*Leptin, a peptide hormone, is secreted by
the adipose tissue and the placenta. It
regulates the body fat metabolism.

64. (IRON METABOLISM)
 Iron is absorbed in ferrous form from duodenum and
jejunum and is released in the circulation as transferrin.
 About 10% of ingested iron is absorbed
Iron freed from transferrin is incorporated into hemoglobin
(75%) & myoglobin or stored as ferritin or hemosiderin.
 Iron is transported actively across the placenta to the fetus.
Iron requirement during pregnancy is considerable and is mostly
limited to the 2nd half of the pregnancy especially to the last 12
weeks.

65. (IRON METABOLISM)
 The iron requirement during pregnancy is estimated
approximately 1000mg.
 This is distributed in fetus and placenta 300mg and expanded
red cell mass 400mg (Total increase in red cell volume = 350ml
and 1ml contains 1.1 mg of iron).
 There is obligatory loss of about 200mg through normal routes.
The iron in fetus and placenta is permanently lost and a
variable amount of iron in the expanded RBC volume is also lost
due to blood loss during delivery (45 mg/100ml) and rest is
returned to the store.

66. (IRON METABOLISM)
 There is saving of about 300mg of iron due to amenorrhea for
10 months.
 Iron loss in menstrual bleeding per cycle is 30 mg
 Iron need is mostly limited to the third trimester.
 Daily iron requirement in non-menstruating women to
compensate the average daily loss is 1 mg.
 Thus, in the 2nd half of pregnancy, daily requirement,
actually becomes very much increased to the extent of about 6-
7mg.

67. (IRON METABOLISM)
 Serum ferritin level reflects the body iron stores.
 In the absence of iron supplementation, there is drop of
hemoglobin, serum iron & serum ferritin concentration at term
pregnancy.
 However, placenta transfer adequate iron to the fetus,
despite severe maternal iron deficiency.
 Thus, there is no correlation between hemoglobin
concentration of the mother and the fetus.

68. SKELETAL CHANGES
 Increase demand of calcium up to 28gm, 80% of which required
in last trimester
 Daily requirement of calcium during pregnancy and lactation
averages 1-1.5gm
 Maternal total calcium levels fails but serum ionized calcium
level is unchanged
 50% of serum calcium is ionized which is important for
physiological function

69. SKELETAL CHANGES
 Calcium absorption from intestines and kidneys are doubled due to
rise in the level of 1,25 dihydroxy vitamin D3
 Pregnancy does not cause hyperparathyroidism
 Calcitonin levels increase by 20% and protects from osteoporosis
 Maternal serum phosphate levels is unchanged
 Increased mobility of pelvic joint d/t softening of ligaments by
hormones
 Increased lumbar lordosis during later months d/t enlarged uterus
causing bakchache and waddling gate.

70. PSYCHOLOGICAL CHANGES
 Nausea, Vomiting, mental irritability & sleeplessness due to
some psychological background
Body image changes
Emotional insecurities
Cultural expectations & support from partner
Financial situations
Whether pregnancy is unexpected
 Postpartum blues, Depression & Psychosis