A brief of the physiological changes in pregnancy for quick revision for undergraduate medical students

1. PHYSIOLOGICAL CHANGES IN PREGNANCY

2. Reproductive system
 Non-pregnant uterus – 70 gm/10 ml
 Globular / spherical by 12 weeks
 Ovoid, extends beyond pelvis after
12 weeks
 Dextrorotation

3.  Uteroplacental blood flow
at term – 500 to 750
ml/min
 Hyperaemia of vagina and
cervix – Chadwick's sign

4. Skin
 Striae gravidarum
 Linea alba/nigrans
 Chloasma
 Vascular spiders
 Palmar erythemas

5. Urinary system

7. GI Tract
 Pyrosis (heartburn)
 Reduced esophageal peristalsis, lax UES
 Slower intestinal peristalsis
 Gastric emptying time – unchanged
 Reduced GB contractility – sludge formation

8. Respiratory system

9. Cardiovascular system / Hematological Changes
 Hypervolemia – 40 to 45%
 Increased erythrocyte volume
 Mild fall in hematocrit/Hb
concentration
 Hypercoagulable state (except XI
and XIII)

11.  Displacement left and upwards
 ECG:
 Left axis deviation
 Q waves in II, III, avF
 Heart sounds:
 Soft systolic murmur
 Loud S3
 Exaggerated splitting of S1

12. Endocrine/Metabolic functions
 Maternal weight gain
 Water retention
 Carbohydrate metabolism:
 Mild fasting hypoglycemia,
 postprandial hyperglycemia,
 hyperinsulinemia
 Accelerated starvation ketosis – change in fuels from glucose to lipids