Physiological changes during pregnancy in all the three stages of pregnancy. Changes inculding genital, metabolic, cardiovascular, haematological etc.

1. PHYSIOLOGICAL
CHANGES DURING
THE PREGNANCY
By Dr Meenu Priya A
MD Part 1 (Sr)
GHMC&H, Bengaluru

2. 1. Physiological changes of pregnancy in Genitalia
(10)
2. Physiological changes of pregnancy in Uterus (5)
3. Braxton-Hicks Contraction (5/3)
4. Physiological Cutaneous changes in Pregnancy (5)
5. Striae Gravidarum (3) Viva
6. Linea Nigra (3) Viva
7. Physiological Haematological changes in
Pregnancy (5)
8. Physiological Cardiovascular Changes in
Pregnancy (5)
9. Mammary Murmur (3) Viva
10. Axillary Tail (3) Viva
11. Supine Hypotension Syndrome (3) Viva

4. PREGNANCY STAGES

5. Can be explained under….
1. Genital Organs
2. Breast changes
3. Cutaneous changes
4. Weight Gain
5. Body water metabolism
6. Hematological Changes
7. Cardiovascular system
8. Metabolic Changes
9. Systemic Changes

6. GENITAL ORGANS

7. VULVA
▪ Oedematous
▪ More vascular
▪ Superficial varicosity (Multipara)
▪ Labia Minora: Pigmented and
Hypertrophied

8. VAGINA
▪ Hypertrophy
▪ Oedematous
▪ More Vascular
▪ Jacquemier’s sign
▪ Increased anterior vaginal wall length
▪ Secretion: Copious, thin and curdy white (exfoliated cells and bacteria)
▪ Acidic pH (3.5-6)
▪ High estrogen → Lactobacillus acidophillus → converts glycogen into lactic acid
▪ Prevents multiplication of pathogenic organisms
▪ Cytology: Navicular cells, lactobacillus.

9. UTERUS

10. UTERUS
Body Isthmus Cervix
changes
SIZE NORMAL PREGNANT
{Term}
LENGTH 7.5 cm
{7.5 x 5 x 2.5}
35cm
WEIGHT 60g 900-1000g
CAPACITY 5-10 ml 500-1000 times

11. BODY OF THE UTERUS
ENLARGEMENT
i. Hypertrophy and Hyperplasia
ii. Stretching
ARRANGEMENT OF MUSCLE FIBRES
i. Outer longitudinal: Hood like
arrangement
ii. Inner circular: Scanty, Sphincter like
arrangement around tubal orifices and
internal os
iii. Intermediate: Thickest and strongest;
Criss cross form; blood vessels run
through it; Apposition of two muscle
fibres : Figure of 8 form; Living Ligature

12. VASCULAR SYSTEM
▪ Uterine and Ovarian arteries equally
▪ Spiralling of arteries; Max at 20 weeks, then straighten out
▪ Uterine artery diameter: doubled and blood flow increases by 8 fold at 20weeks
▪ Hormones
▪ Veins: Dilated and valveless
▪ Lymphatic channels: numerous open up
▪ Vascular changes more in Placental site
WEIGHT: 900-1000g
SHAPE: Pyriform → Globular → Pyriform/Ovoid → Spherical

13. POSITION
▪ Anterverted position → excaggerated upto 8 weeks → Increased
frequency of micturition {enlarged uterus lie on bladder}
▪ Then becomes erect. Long axis conforms to axis of inlet, held firmly
against maternal spine
▪ Multiparae: Lax Abdominal wall → Anteversion
LATERAL OBLIQUITY
▪ Uterus: Dextrorotation
▪ Cevix: Levorotation
UTERINE PERITONEUM
▪ Proportionate relation with growing uterus
▪ Uterosacral ligaments and bases of braod ligament rise upto the level
of pelvic brim
▪ Deepens the pouch of douglas
▪ Lower lateral walls uncovered by peritoneum
▪ Filled by loose and vascular connective tissues

14. BRAXTON-HICKS CONTRACTION
Irregular, infrequent, spasmodic and painless without any effect on
dilatation of cervix
▪ Named after Braxton hicks
▪ Spontaneous contractions of uterus from early weeks
▪ Felt during bimanual palpation and abdominal palpation
▪ Uterus firm at moment and soft at another
▪ Excited by rubbing the uterus
▪ Patient is not conscious {increases in frequency and intensity near term → discomfort to pregnant
women}
▪ Absent in abdominal pregnancy
▪ Transient fetal hypoxia → fetal bradycardia

17. ISTHMUS

18. CERVIX
▪ Copious tenacious secretion
▪ Forms thick plug, seals the cervical canal
▪ Length unaltered
▪ Bulky cervix

19. FALLOPIAN TUBE
▪ Total length increased
▪ Congestion of tube
▪ Hypertrophy
▪ Flattened epithelium
▪ Few decidual reaction
▪ Uterine end rises up
▪ Fimbrial end held up by infundibulo-pelvic ligament
▪ Vertical by side of uterus
▪ Term: Lower end of upper one-third

20. OVARY
▪ Corpus Luteum- Max size at 8th week, 2.5cm, cystic
▪ Bright orange → Yellow → Pale
▪ Regression due to reduced hCG
▪ 12th week: Colloid degeneration; Term: Calcified
▪ Hormones inhibits follicle ripening
▪ Ovarian and uterine cycles → Suspended
▪ Control formation and maintenance of decidua pf pregnancy

21. BREAST CHANGES

23. ▪ Primigravida
SIZE
▪ Increase in size
▪ Hypertrophy and proliferation : Ducts
and alveoli (Periphery)
▪ Hypertrophy : Myoepithelial cells
▪ Bluish veins under skin
▪ Axillary Tail : enlarged and painful
▪ Striae
NIPPLES AND AREOLA
▪ Larger, erectile, deeply pigmented
▪ Montgomery’s tubercles
▪ Moist and healthy
▪ Secondary areola
SECRETION (Mammogenesis)
▪ Colustrum
▪ 12th week: Sticky
▪ 16th week: thick and yellowish

24. CUTANEOUS CHANGES

25. CHLOASMA GRAVIDARUM LINEA NIGRA STRIAE GRAVIDARUM
STRIAE ALBICANS VASCULAR SPIDER PALMAR ERYTHEMA

26. WEIGHT GAIN

27. Reproductive Weight Gain Foetus 3kg
Placenta 0.6kg
Liquor 0.8kg
Uterus 0.9kg
Breasts 0.4kg
Fat and Protein
accumulation
3.5kg
Maternal Weight Gain Extracellular fluid 1.3kg
Blood Volume 1.3kg
▪ Initially weight loss
▪ Followed by weight gain
▪ Last 2 weeks, static
▪ Total gain: 11kg
▪ 1st trimester: 1 kg
▪ 2nd Trimester: 5kg
▪ 3rd Trimester: 5 kg
• RAPID WEIGHT GAIN
• STATIONARY OF FALLING WEIGHT
• BMI

28. BODY WATER METABOLISM

29. ▪ 6.5 litres : retained water at term
▪ Foetus, placenta, amniotic fluid: 3.5 litres
▪ Hypervolemia
▪ Retention of : Sodium, Potassium and
water
✓ Osmoregulation
✓ Estrogen and progesterone
✓ Renin-Angiotensin activity
✓ Aldosterone and deoxycorticosterone
✓ Arginine Vasopressin
✓ Atrial Natriuretic peptide
▪ Thirst and ADH secretion : osmotic threshold
resetting (after 8 weeks)
▪ Vasopressinase from placenta : ADH
▪ Polyuria : early months
▪ Atrial and brain natriuretic peptide : Diuretic,
natriuretic, vasorelaxant
▪ Antagonist to Renin Angiotensin mechanism

30. HEMATOLOGICAL CHANGES

31. BLOOD VOLUME
▪ Increased
▪ From 6th week
▪ 40-50% by 30-32 weeks, then static
PLASMA VOLUME
▪ 50%
▪ Up to 1.25 litres
RBC AND HAEMOGLOBIN
▪ 20-30%
▪ 350ml
▪ High oxygen demand
▪ From 10 weeks
▪ Enhanced by iron supplement
HEMODILUTION

32. Hemodilution advantage
✓ optimum gaseous exchange between maternal and fetal circulation
✓ Supine and erect posture
✓ Blood loss adverse effects
LEUCOCYTES
▪ Neutrophilic leucocytosis till 8000/cu.mm till 20,000/cu.mm in labor (estrogen and cortisol)
IMMUNE SYSTEM
▪ Increased humoral and innate immune responses
TOTAL PROTEIN
▪ 180g → 230g
▪ Plasma Protein : 7g → 6g
▪ Albumin : 4.3 → 3
▪ Globulin: 2.7 → 3
▪ A:G ratio: 1.7:1 → 1:1

33. BLOOD COAGULATION FACTORS:
▪ Hypercoagulable state
▪ Fibrinogen: 200-400 mg/dl → 300-600 mg/dl
▪ ESR: 10 mm/hr → 40 mm/hr
▪ Platelets: static or reduced by 15% → Gestational
thrombocytopenia
▪ Fibrinolytic activity: depressed till 15mins after
delivery
▪ Clotting factors: High: X, IX, VIII, VII, I ; II, V, XII: no
change or mild increase; low: XI, XIII
▪ Clotting time : No change
▪ Normalised coagulation factors: 2 weeks postpartum.

34. CARDIOVASCULAR SYSTEM

35. ▪ Heart is pushed upwards and outwards → Palpitations
▪ Apex Beat: 4th intercostal space, 2.5cm outside midclavicular line
▪ PR: high, extrasystoles
▪ Systolic murmur: Apical/pulmonary area
▪ Mammary murmur: continuous hissing murmur – tricuspid area
▪ 3rd heart sound; 4th heart sound?
▪ Cardiac Output: 5th week; 40-50% rise by 30-34 weeks; static
thereafter
▪ Low: sitting/supine; High: Right or left lateral / knee chest position
▪ 50% during labor; 70% immediately after delivery → Auto
tranfusion
▪ High blood volume, High O2 demand
▪ Stroke Volume: high: 27%; Pulse Rate: 85 (17%)

36. ▪ BP: Normal or decreased → SVR
(Systemic Vascular Resistance)
▪ Diastolic BP and MAP: Reduced
Venous Pressure
▪ Antecubital venous pressure: Normal
▪ Femoral venous pressure: High (100%)
→ Oedema > rest
Central Hemo dynamics:
▪ CVP, MAP, PCWP: Normal → Low SVR,
PVR, Colloidal osmotic pressure
SUPINE HYPOTENSION SYNDROME
(POSTURAL HYPOTENSION)
▪ Compression on IVC → Collateral
circulation → Paravertebral and azygous
veins
▪ Lateral position
REGIONAL BLOOD FLOW
▪ Uterine blood flow: 50mL/min → 750 mL
near term (Vasodilatation)
▪ Pulmonary blood flow: >> 2500 mL/min
▪ Renal blood flow: >> 400 mL/min
▪ Skin and MM: 500 mL/min by 36th week
▪ Heat sensation, sweating or stuffy nose

37. METABOLIC CHANGES

38. GENERAL
▪ BMR: >>30%
PROTEIN
▪ Positive nitrogenous balance
▪ Placenta: 500mg; Maternal: 500mg
▪ Urea: Reduced: 15-20mg%
▪ Anabolic
▪ AA: active transportation
FAT
▪ 3-4 kg increase
▪ Plasma lipids and lipoproteins
LIPID
▪ HDL: 15%; LDL: 40%; Total lipid: 50%;
Triglycerides: 50%
▪ Placental steroidal synthesis: LDL used
▪ Not atherogenic hyperlipidemia
▪ Leptin

39. CARBOHYDRATE
▪ High glucose
▪ Insulin high → Hyperplasia and hypertrophy of beta
cells of pancreas
▪ Sensitivity of insulin receptors, decreased
▪ Plasma insulin high (contrainsulin factors)
▪ Continuous supply of glucose to foetus
▪ Lipogenesis
▪ Maternal fasting: hypoglycemia, hypoinsulinemia,
hyperlipidemia, hyperketonemia
▪ FBS: hypoglycemia
▪ PPBS: Hyperglycemia, hyperinsulinemia
▪ Glycosuria
▪ Gluconeogenesis, Glycogenolysis

40. IRON
▪ Requirement: 1000 mg (high in 3rd trimester)
▪ Foetus and Placenta: 300mg
▪ Red cell mass: 400mg
▪ Amenorrhoea: 300mg
▪ 200mg lost everyday
▪ 700mg lost permanently
▪ Daily requirement: 6-7mg

41. SYSTEMIC CHANGES

42. RESPIRATORY SYSTEM
▪ Elevation of Diaphragm: 4cm
▪ TLC: Reduced by 5%
▪ TPR: Reduced
▪ Subcostal angle: 68 0 → 103 0
▪ Mucosa of Nasopharynx:
Hyperaemia + Oedema
▪ Increase TV: Hyperventilation
▪ PaCO2 38 → 32 mmHg
▪ PaO2 95 → 105 mmHg
▪ Respiratory Alkalosis
▪ Base high by 2 mEq/L
▪ Maternal O2 high by 20-40%

43. URINARY SYSTEM
▪ Dilatation: Ureter, Renal Pelvis,
Calyces
KIDNEY
▪ 1cm >> Kidney length
▪ Renal Plasma Flow >> 50-75%
▪ GFR >>> 50%
▪ << Creatinine, BUN, Uric acid
URETER
▪ Atonic
▪ Dilatation above pelvic brim, right
side
▪ Hypertrophy
▪ Elongation, Kinking and outward
displacement
BLADDER
▪ Hypertrophy + congestion
▪ Bladder mucosa: Odema → late
▪ Micturition
✓ Increased 6-8 weeks
✓ Normal after 12 weeks
✓ Late pregnancy: increased
▪ Stress incontinence

44. ALIMENTARY SYSTEM
▪ Bleeding and spongy gums
▪ Tonicity and motility <<< (more absorption)
▪ Cardiac sphincter – Relaxed
▪ Chemical Oesophagitis, heartburn
▪ PUD risk reduced
▪ <<< gastric secretion + delayed emptying
▪ Constipation

45. LIVER AND GALLBLADDER
▪ No histological changes
▪ Depressed function
▪ LFT: Normal
▪ Mild Cholestasis
▪ Atonicity of GB
▪ High blood cholesterol
▪ Cholelithiasis

46. NERVOUS SYSTEM
▪ Temperamental changes
▪ Postpartum blues
▪ Depression/Psychosis
▪ Nausea, vomiting, mental irritability,
sleeplessness
▪ CT Syndrome (Median nerve compression)
▪ Lateral cutaneous nerve of the thigh:
Compression: Paraesthesia, sensory loss →
Antero lateral part of thigh

47. LOCOMOTOR SYSTEM
CALCIUM METABOLISM
▪ 28g increase in demand
▪ 1-1.5g daily requirement
▪ Maternal total calcium level <<<
▪ Ca absorption >>> 1.25 dihydroxy vitamin D3
▪ >> Calcitonin → Prevents Osteoporosis
▪ >>> mobility of pelvic joints
▪ Lumbar lordosis
▪ LBA, Waddling gait