ys o og ca
anges anges ur ng regna regnanc ncy y
Metabolic Changes Placenta secretes hPL (human placental lactogen) (also known as hCS (human chorionic somatomammotropin)) hPL Promotes growth of fetus Exerts a maternal glucose-sparing effect hCT (Human chorionic thyrotropin) Maternal metabolism Parathyroid hormone +ve calcium balance Physiological Changes GIT Morning sickness (due to estrogen, progesterone) Urinary system Urine production (handle additional fetal wastes) Respiratory system Edematous Nasal congestion Dyspnea (may develop late in pregnancy) CVS CO ( Stroke volume) Apex beat moved laterally Cardiac capacity (70-80mL)(due to volume/ hypertrophy of cardiac ms.) BP Venous pressure Pressure of pregnant uterus on femoral vein, IVC Impede blood flow from legs Venous pressure Force fluid out cause edema Distensibility Distensibility of veins Lateral recumbent position (relief pressure on femoral vein, IVC) Hematological system Total plasma volume Blood volume Blood flow to uterus, kidneys Serum albumin - Oncotic pressure general edema (lower limbs) RBC Red cell volume (but lag behind plasma volume) Hematocrit, [Hb] Physiological Physiological anaemia of pregnancy pregnancy Stimulate erythropoiesis progesterone, hPL, PRL Iron requirement (maternal iron deficiency) Total WBC Clotting factors Pulmonary system Engorgement of nasopharynx, larynx, trachea, bronchi (capillary dilatations) Voice change, breathing via nose difficult, CXR - vascular markings markings in lungs Tidal volume FRC (functional (functional residual capacity) pCO2 (secondary to alveolar hyperventilation) Bicarbonate (metabolic compensation) pO2 while upright (may fall when supine) Pulmonary circulation Pulmonary vascular resistance Pulmonary blood flow Pulmonary blood volume O2 consumption (due to metabolic demands of fetus, uterus, placenta) y
y
y y
y y
y
y
y y y y
Physiological Changes (cont.) Urinary system Renal dilatation Length, Weight of kidneys Dilated Renal pelvis, Ureters (urinary (urinary stasis - infection) Hydronephrosis, Hydroureter Progesterone (hypotonia of smooth ms. in ureter) Enlarged ovarian vein complex (dilatation) Dextrorotation of uterus Hyperplasia of smooth ms. Renal plasma flow rate GFR (but volume of urine passed is not increased) Glucosuria ( GFR impaired tubular reabsorption capacity to filter glucose) Proteinuria Renin Bladder Urinary frequency (pressure from uterus) Bladder vascularity Muscle tone Bladder capacity y y
y y y y
y y y y
GIT system GIT motility (due to progesterone) (constipation) Gastric reflux Gums hypertrophy, Vitamin C deficiency, Bleeding gums ALP (liver) Reproductive Goodells sign softening of cervix (on pelvic exam) Chadwicks sign purple hue of vagina, cervix Hegars sign compressibility, softening of isthmus Uterine hypertrophy (of myocytes) Venous return CO TPR (to minimize fall in BP) Endocrine system Anti-insulin environment, aided by Placental lactogen Similar to GH Lipolysis, FFA Tissue resistance to insulin Unbound cortisol Estrogen, progesterone exert anti-insulin effects Thyroid TBG Total T3, T4 hCG stimulates thyroid ( TSH) Iodine deficiency state ( r enal clearance) y y y
y
y y
y y y y
Metabolism Weight Uterus and its contents Breast tissue, blood, water volume Average weight 12.5kg CVS Estrogen - RAA Stimulate erythropoiesis progesterone, hPL, PRL CVS changes due to a-v shunt through placenta (late pregnancy) Pulmonary Intraabdominal pressure (force diaphragm upward) BMR of growing fetus - maternal O2 consumption, CO2 production Progesterone acts on CNS to set-point for regulation of respiration by CO2 ( Ventilation) Renal RAA (due to BP) Estrogen stimulates liver synthesis of angiotensinogen Estrogen, progesterone - ACE DOC (placental deoxycorticosterone) Mineralocorticoids Aldosterone CNS Sensitivity to PaCO2 Volume of epidural space Pressure of epidural space CSF volume CSF pressure Sensitivity to local anaesthetics Local anaesthetic dose y y y
y y
Dead volumes Tidal volumes Total lung capacity Functional residual capacity, residual volume, respiratory respiratory reserve volume
