Changes occur in several body systems during pregnancy, including the cardiovascular, respiratory, gastrointestinal, and urinary systems. The cardiovascular system experiences an increased cardiac output of around 40% due to higher stroke volume and heart rate. Respiration increases through a 40% rise in tidal volume without changing breath frequency. The gastrointestinal system exhibits nausea, increased appetite, and constipation. The urinary system shows an enlarged kidney and dilated ureters along with higher glomerular filtration rate and decreased serum creatinine.

2. Changes occur in:
 CARDIO VASCULAR SYSTEM
 RESPIRATORY SYSTEM
 GASTROINTESTINAL SYSTEM
 URINARY SYSTEM

3. 1.HEART
 The heart is pushed upwards and rotated
by elevation of the diaphragm.
 Apex beat is felt at the fourth intercostal
space and lateral to the midclavicular line.
 Straightening of the left border.
 Exaggerated impression of cardiac
enlargement.
CARDIOVASCULAR SYSTEM

4. Mild increase in size due to increased venous
filling.
Changes in ECG are also seen

5. 2.CARDIAC OUTPUT
 Increase in cardiac output of almost 40%
both due to increase in stroke volume and
pulse rate.
 This begins early in pregnancy and atleast
2/3rds of this increase is in the 1st
trimester.
 Oxygen consumption at rest increases to
meet the needs of fetus and to support the
increased metabolic rate of the mother.

6.  CO increases still more in labour.
15% in 1st stage of labour.
50% in 2nd stage of labour.
 Following delivery there is an immediate rise in
CO due to:
> Relief of inferior vena caval obstruction
> Uterine contraction that empties the blood
to systemic circulation.

7.  CO increases by 60-80% followed by rapid
decline to prelabour value within 1 hour.
 CO returns to normal after 2 weeks following
delivery.

8. 3.BLOOD PRESSURE
 Even though CO increases,there is no
change in BP as peripheral resistance
decreases massively.
 Diastolic Blood pressure falls in the second
trimester and it may return to normal in the
third trimester.

9. 4.SUPINE CAVAL SYNDROME
 Turning from lateral to supine position may
result in a 25% reduction in cardiac output.
 In supine position, pressure of gravid
uterus on IVC reduces venous return to
heart and this leads to fall in the stroke
volume and cardiac output.

10. 5.RENIN ANGIOTENSIN II
 Renin is produced by maternal kidney and
placenta.
 Angiotensinogen is produced by the
maternal and the fetal liver.
 As a result all components of this axis are
increased in normal pregnancy.

11. RESPIRATORY SYSTEM
ANATOMICAL CHANGES
 Lower ribs flare out.
 Subcostal angle increases 68 to 103 degree
 Transverse diameter of the chest increases by
2 cm.
 Diaphragm rises about 4 cm.

12. FUNCTIONAL CHANGES
 Increase in ventilation is achieved by an
increase in Tidal Volume by 40% (500-
700ml)
 Pregnant women does not breath more
frequently, but she breath more deeply.
 No change in vital capacity.

13.  O2 consumption increases by 30-40 ml per
minute to supply the fetus and for extra
metabolism in pregnancy.
Physiological dyspnoea is present due to the
increased tidal volume.
Increased ventilation decreases PCO2 slightly.

14.  The reduced PCO2 from maternal
hyperventilation helps in CO2 transfer from
fetus to mother and facilitates oxygen
release to fetus.
 Functional residual capacity and residual
volume are decreased due to the elevated
diaphragm.
 The total haemoglobin mass and total
oxygen carrying capacities are increased.

15. GASTROINTESTINAL
SYSTEM
ANATOMICAL CHANGES
 Enlarging uterus compresses the rectum
resulting in an increased sensation of need
to defecate.
 Pregnancy displaces the bowels upwards
and sidewise. Tenderness of acute
appendicitis may not be over McBurney’s
point during pregnancy.

16. Lower esophageal sphincter is defunct
resulting in reflux esophagitis.
Haemorrhoids are also common due to
pressure by the gravid uterus.

17. FUNCTIONAL CHANGES
 Nausea and Vomiting
 It is due to reduced mobility of the gut in
pregnancy and by the hCG in circulation.
 Women tend to have better appetite and eat
more.
 They also have strong likes and dislikes for
particular foods termed “pica”.

18.  Increased demand cause increased
absorption of iron and calcium.
 Heart Burn is common due to reflux of acid
secretion into the lower oesophagus.
 Constipation is due to progesterone induced
relaxation of the gut.

19. Gastric emptying is also reduced.
Gallstones occur at a high frequency due to
raised cholesterol level and increased
saturation of bile estrogens.

20. URINARY SYSTEM
ANATOMICAL CHANGES
 Small enlargement in the size of the kidney
and dilatation of the renal pelvis.
 Ureters become atonic and dilated both due to
the pressure of the gravid uterus and the high
progesterone level.
 It makes women more prone to ascending
infection and pyelonephritis.

21. FUNCTIONAL CHANGES
 Renal blood flow increases by 80% in the
second trimester, but falls in the third
trimester.
 GFR increases by 50%.
 Serum creatinine level falls in pregnancy due
to increased renal clearance.

22. Serum urea and uric acid level also
decreases in pregnancy.
Glucose may be present in urine due to
defective tubular reabsorption of glucose
results in lowering of renal threshold in
pregnancy (Nl- 180mg/dl).
5% of pregnant women may show
proteinuria.

23. Exit