7. Reproductive system
• Uterus:
• Enormous growth
• Non pregnant- wt 50gm, length- 7.5cm
• At term- wt-900-1000gm(uterine muscles,
connective tissues, vascular channels), length-
35cm
• Body of uterus:
• Hypertrophy & hyperplasia, stretching of uterine
muscles
8. Reproductive system
• Non pregnant- most supply – uterine & least –
ovarian artery
• Pregnancy- ovarian artery supplies more
• Marked spiralling – arteries max at 20wks,Veins-
dilated
• Numerous lymphatic channels- open up
• Fundus enlarges more than body
• Braxton hick’s contraction- irregular, infrequent,
spasmodic, painless, without any effect on cx
dilatation
10. Reproductive system
• Endometrium- decidua
• Isthmus:
• 1st trimester: hypertrophies & elongates( 3 times
original length), softens
• Beyond 12 wks- progressively unfolds from
above, downwards & incorporates into uterine
cavity
• Circularly arranged muscle fibres- function as
sphincter in early pregnancy- retains fetus within
uterus
11. Reproductive system
• Cervix:
• Stroma- hypertrophy & hyperplasia
• Increased vascularity
• Goodell’s sign- softening of cx- 6 wks onwards
• Epithelium- prolifzration of endocervical mucosa
• Secretions- copious & tenacious- physiological
leucorrhoea of pregnancy( progesterone)
• Mucus forms a thick plug- seal cervical canal
15. Gastro intestinal system
Anatomical
1. ↑Angle of GE junction
2. Cephalad displacement of
stomach & intestine
3. Vertical rather than horizontal
stomach
Physiological
1. Relaxed LES (progesterone)
↓barrier P.
2. Delayed gastric emptying
(narcotics, anticholinergics,
pain of labour)
16. Cutaneous changes
• striae gravidarum & striae albicans
• Linea nigra
• Increased pigmentation of the nipple as primar
areola and appearance of the secondary
areola.
• Cloasma gravidarum / mask face of pregnancy
which is butterfly pigmentation of the
forehead, nose, upper lip and the adjoining
parts of the cheeks.
20. Nervous system
Functional changes may appear especially in
neurotic women as :
-sleepy, depressed
-while others become irritable, excited and suffer
from insomnia.
-The nausea and vomiting may have a neurotic
element.
-Change of appetite such as refusal of some types
of food.
-Neuralgias
21. Wt gain & metabolism
Wt GAIN = 17%
= 11-12 kg T1 = 1-2 kg
T2 = 5-6 kg
T3 = 5-6 kg
BMR +15% at term
O2 consumption +35% (↑needs of fetus, uterus,
placenta)
+ 40% in stage I of labour
+ 75% in stage II of labour
22. Body water metabolism
• Pregnancy- hypervolemia
• Active retention of – NA (900mmol), K (350 m
mol) & H2O – ( ↑ oestrogen, progesterone,
↑renin angiotensin activity)
• Reseting of osmotic threshold( lowered
osmotic threshold)- increased thirst- increase
water intake- polyuria upto 8 wks)
• H2O retained at term- 6.5 L
23. Calcium metabolism
• ↑ demand- Ca- growing fetus- 28 gm
• Daily Ca reqiurement- 1-1.5gm/day
• Maternal total calcium level- falls
• But serum ionised ca level- unchanged
• Ca- absorption is – doubled from intestine&
kidneys- ↑1,25 dihydroxy vitamin D3
• Calcitonin level- increases- 20%
• Maternal serum phosphate - unchanged
24. Fe metabolism
• Fe- absorbed- ferrous form- duodenum &
jejunum
• Released in circulation – Transferrin
• Fe- transported actively- across placenta- fetus
• Total Fe requirement during pregnancy -
1000mg( distributed fetus, placenta-300mg &
expanded red cell mass– 400mg)
25. Respiratory system
• hyperventilation due to high level of
progesterone.
• Breathing -more costal than abdominal. Most
• women are mouth breathers -during
pregnancy.
• Anatomically- the diaphragm is progressively
elevated
26. Respiratory system
1. Anatomical
a) Rib cage enlargement
b) Diaphragm pushed cranially- changes in lung
vol
c) ↑ mucosal engorgement
nasal – epistaxis
d) ↓Chest wall compliance (lung compliance
unaffected)
e) Subglottic airway dilatation (progesterone,
cortisone, relaxin) →↓pulmonary resistance (-
50%)
27. Respiratory system
PARAMETER CHANGE
1. TV +45%
2. FRC -20%
3. ERV -25%
4. Dead space +45%
5. RR No change/+
6. MV +45%
7. Alveolar ventilation +45%
change in MV is solely due to ↑in TV and not
RR
28. Respiratory system
2. Physiological changes
1. ↑MV → ↑ TV (RR unchanged)
1. Progesterone (↑CNS sensitivity
to CO2)
2.↑CO2 production
alkalosis (compensatory but
incomplete↓HCO3
- →↑pH by 0.02-0.06)
2. Breathing diaphragmatic > thoracic
30. Cardio vascular changes
• Heart- pushed upwards & outwards
• Displacement- palpitation
• Systolic murmer may be audible- mammary
murmer- ↑ bld flow through internal
mammary vessels
• ECG- normal
• ↑vacularity – enlarging uterus
31. Cardio vascular changes
• Blood volume- ↑ ( 40- 50 %)
• Plasma Volume- ↑ 50%- 1.25 L
• Increase O2 demand Increased CO( 40 %)
• Slight increase in HR, Increase in SV.
• SVR - ↓ ( -21%)
• Pulmonary vascular resistance- ↓ ( - 34%)
• Stable BP with increased CO means decreased
SVR (drop of diastolic pressure – midpregnancy-
5- 10 mm Hg)
32. Cardio vascular changes
Blood pressure
Position
max. in supine
min. in lateral
Age
↑with age
Parity
nullipara> multipara
SV(↑)
SBP SBP unaffected
vsl distensibility(↑compliance)
BP
DBP SVR(↓) DBP ↓
33. Cardio vascular changes
Aortocaval compression : starts at 13-16 wk
Concealed caval compression.
In supine position gravid uterus compresses IVC & ↓CO
without fall in the blood pressure.
no fall in blood pressure
1.Reflex vasoconstriction
2.Diversion of blood through paravertebral &
epidural venous plexus, ovarian veins – maintains
VR
34. Cardio vascular changes
Overt caval compression (supine hypotensive
syndrome)
Hypotension, sweating, bradycardia, pallor, nausea,
vomiting.
Due to uncompensated ↓VR
Prevention of SHS: (aim is to displace the uterus)
1.Providing left lateral tilt 15 degrees beyond 28wk
2.Placing wedge under the right buttock
35. Haematological changes
• Blood volume- ↑ ( 40- 50 %), (4000 →5500ml)
• Plasma Volume- ↑ 50%- 1.25 L( 2500 → 3750ml)
• RBC volume- ↑ 20-30%- (volume – 350 ml)
• Disproportionate ↑ plasma & RBC vol- state of
haemodilution in pregnancy
• Total plasma protein level- ↑ ( 180 → 230gm)
• But haemodilution- plasma protein conc falls (
7gm% →6gm%)
