The surprising effects of pregnancy
Physiological Changes During Pregnancy
| Changes | Increase | No change | Decrease |
|---|---|---|---|
| CVS | CO, SV, HR, femoral venous pressure | JVP, S2, S3 | Peripheral vascular resistance (d/t progesterone) → sBP, dBP, MAP |
| Heart sounds | Loud S1 with splitting, cardiac shadow | Normal findings: |
Ejection systolic murmur, continuous murmur Left axis deviation on ECG Maternal souffle | | | Hematological | ↑ Blood, plasma, RBC volume ↑ Hb mass → ↑ O2 carrying capacity | | PCV Hematocrit Viscosity Hb concentration | | Coagulation | Clotting factors (except factors XI, XIII) | CT, BT, aPTT | Platelet count, factor XI, XIII | | Immune system | Humoral immunity (TH2) WBC | CD4:CD8 | Cell mediated immunity (TH1) | | Plasma proteins | Plasma protein mass Globulin ESR, CRP | | Plasma protein concentration Albumin | | Oxygen physiology | ↑ O2 carrying capacity ↑ O2 demand in tissues | O2 dissociation curve: Right shift (to deliver more O2) | ↓ A-V O2 gradient | | Respiratory indices | Mnemonic: IC TV Movie ◦ Inspiratory capacity ◦ Tidal volume ◦ Minute ventilation | Mnemonic: IRV ◦ Inspiratory reserve volume ◦ Respiratory rate ◦ Vital capacity | All other parameters | | Acid-base balance | | Respiratory alkalosis: D/t hyperventilation | | | Renal | Renal blood flow, GFR, clearance (urea, uric acid, creatinine) | | S. urea, S. uric acid, S. creatinine | | Vaginal changes | Vascularity & hyperemia (Chadwick's sign) Cervical secretion (production of thick white vaginal discharge) | Vaginal wall changes: ◦ Epithelial thickening ◦ Connective tissue loosening ◦ Smooth muscle cell hypertrophy | Acidic pH 3.5-6.0 (Lactobacillus acidophilus metabolizes glycogen stores to lactic acid) |