7. Maternal Physiological Adaptations During Pregnancy

7.1 Cardiovascular Changes

  • ↑ Blood volume (30–50%)
  • ↑ Cardiac output (30–50%)
  • ↓ Systemic vascular resistance
  • Physiological anemia of pregnancy (hemodilution)

7.2 Respiratory Changes

  • ↑ Tidal volume
  • Slight ↑ minute ventilation
  • Mild respiratory alkalosis

7.3 Renal Changes

  • ↑ GFR by 40–50%
  • ↑ Renin–angiotensin–aldosterone activity
  • Fluid retention

7.4 Gastrointestinal Changes

  • Progesterone → ↓ GI motility → constipation
  • Relaxation of lower esophageal sphincter → reflux

7.5 Metabolic Changes

  • Insulin resistance due to hPL
  • Increased fat storage
  • Altered carbohydrate metabolism

Chapter 8: Fetal Growth and Development

8.1 First Trimester (0–12 Weeks)

  • Organogenesis
  • Heartbeat detectable by Week 6
  • Limb buds, facial structures appear

8.2 Second Trimester (13–27 Weeks)

  • Rapid growth
  • Movement felt (quickening)
  • Skin development
  • Fetal sex visible by ultrasound

8.3 Third Trimester (28–40 Weeks)

  • Lung maturation
  • Fat deposition
  • Brain growth
  • Fetus assumes head-down position