Maternal Physiology Chapter 05 –Williams Obstetrics 23rd Edition

dr. Tizar Dwi Satyoputro

-ZIO

Physical adaptations during pregnancy

Anatomical and functional changes

• Metabolic Changes

• Hematological Changes

• Reproductive Tract

• Respiratory Tract

• Gastrointestinal Tract

• Cardiovascular System

• Urinary System

• Endocrine System

• Breast Changes

Metabolic changes

Water metabolism Carbohydrate metabolism Weight gain

Hematological changes

Iron turnover Blood volume Coagulation & Fibrinolysis

Blood volume (polymorphonuclear) +40%

Dilutional anemia Hb 110 g/L

Leukocytosis 15,000/ml

Platelet not change

Sedimentation rate increase, 100m/h

Clotting factors: hypercoagulable, throboembolism

Fibrinogen (factor I) +50% (4.5 vs 3 g/L)

Factor VIII increase

Factors VII, IX, X and XII increase

Prothrombin time, PT shortened

ATPP activated partial thromoplastin time shortened

Fibrinolytic activity decrease

Reproductive Tract

Weight: 70 g (before pregnancy) – 1100 g (during pregnancy) Volume: 5 L to 20 L or more – 2500 L to 5000 L or more Shape: pear (beginning) spherical (12w) ovoid Uterine contractions: intensity 5 and 25 mm Hg; frequency 10 to 20 minutes (near term) Uteroplacental Blood Flow: 450 to 650 mL/min near term regulation: estradiol and progesteron administration to modify vascular resistance

Shape: pronounced softening and cyanosis (1m after conception) Increased vascularity and edema, hypertrophy and hyperplasia of the cervical glands Containment: >50% of cervical mass cervical glands (end of pregnancy) Cervical mucus: soon after conception, acts as immunological barrier

Progesterone production: a single corpus in pregnant women (max. 6w to 7w of pregnancy – 4w to 5w postovulation) Diameter of ovarian vascular: 0.9 cm to 2.6 cm (at term)

Appearance: Violet color characteristic of Chadwick sign. Wall: increase in mucosal thickness, loosening of the connective tissue, and hypertrophy of smooth muscle cells pH: 3 to 6 (acidic)

Musculature of the fallopian tubes: a little hypertrophy (during pregnancy) Fallopian tube torsion: increasing size of the gravid uterus

Respiratory Tract

• Mucosal hyperemia

• Subcostal angle

• Chest circumference and diameter

• Diaphragmatic excursion

• Tidal volume +30-40%

• PO2 is increased, PCO2 is decreased.

• Total lung capacity decrease -15%

• Minute ventilation +30-40%

• Mild respiratory alkalosis

Gastrointestinal Tract • Morning sickness

• Hyperremesis gravidarum (weight loss, ketonemia and electrolyte imbalance)

• Dietary craving: pica

• Decreased gastrointestinal motility: reflux and heartburn

• Gallbladder function, cholestasis

• Hyperemia and softening of the gums (epulis)

• Hemorrhoid

• Appendix displaced

Cardiovascular System

Cardiac outline: The blue lines represent the relations between the heart and thorax in the nonpregnant woman, and the black lines represent the conditions existing in pregnancy

Cardiac output

Circulation & Blood pressure

Stroke volume +30% Heart rate +15% Cardiac output +40% Oxygen consumption +20% SVR (systemic vascular resistance) -5% Systolic BP -10mmHg Diastolic BP -15mmHg Mean BP -15mmHg

Blood volume +30%

Plasma volume +40%

Red blood cell volume +20%

Dilutional anemia

Increase cardiac output

Decrease blood viscosity

Vasodilatation

Right shift oxyhemoglobin dissociation curve

Urinary System

GRF – ERPF – Filtration fraction

Protein excretion

Endocrine System

Thyroid physiology Andrenal Glands: Cortisol Thyroid Glands

Breast changes

• Engorgement and venous prominence

Increase in size by 2nd mo –hypertrophy of mammary alveoli

• Tenderness and tingling occur in early weeks of pregnancy

Mastodynia (breast ternderness): tingling to frank pain caused by hormonal responses of the mammary ducts and alveolar system

• Nipples become larger, more deeply pigmented, more erectile

Colostrum, a thick yellow fluid can be expressed from the nipples, may be expressed by the 2nd trisemester

• Montgomery’s tubercles: enlargement of circumlacteal sebaceous glands of the areola

Thank you!