Physiology of Pregnancy

1. Physiology of Pregnancy דר' שמואל לוריא מ.ר. וולפסון, חולון בהצלחה בבחניה!!!!

2. Genitalia Skin Breasts Metabolic changes Hematological Cardiovascular Respiratory Urinary Gastrointestinal Endocrinology Thyroid Hypermesis Musculoskeletal Eyes CNS Plan of the lecture

3. Genital tract – uterus • From 70 gr/10 ml to 1100 gr/5000 ml • Growth 500-1000 times • Patterns of growth: • Hypertrophy • Fibrous tissue • Vessels, lymphatics • Asymmetrical • Fundus>other parts • Placental site>other parts

4. Genital tract – uteruscont • Contractility • 1 trimester onwards • Braxton-Hicks (Hicks JB 1823-1899) • Blood flow • 450-650 ml/min (40W) • Regulation • Estrogen/Progesterone • Catecholamines/Angiotensin II • Nitric oxide (vasodilator)

5. Genital tract – cervix • Continuous softening • Increased vascularity • Hypertrophy & hyperplasia of cervical glands • Mucus plague obstruction • (Bloody show) • Squamous Metaplastic Cells • Size, shape, staining • PAP interpretation

6. Genital tract – vagina • Increased vascularity • Violet color • Chadwick sign (1844-1905) • Wall distention • Increased thickness of mucosa

7. Genital tract – ovaries • Ovulation ceases during pregnancy. • Corpus luteum up to 7th week

8. Genital tract – ovariescont • Luteoma of pregnancy • Solid ov tumor • Exaggeration of normal lutianization • May be up to 10 cm • Regresses after delivery

9. Skin • Pigmentation • Linea nigra • Chloasma or melasma • Around areola • m/p increased MSH

10. Skin cont • Striae gravidarum • Vascular changes • Palmar erythema • Vascular spiders

11. BREAST • Increased size • Increased areola size • Colostrum • 2nd trimester onwards

12. BREAST cont • Increased areola size • Pigmentation • Montgomery • Pimple like gland • Secrete lubrication for areola

13. Weight gain Fetus, placenta 4.2 Amniotic fluid 0.8 Uterus 1.0 Breasts 0.4 Blood volume 1.5 3rd space 1.5 Fat 3.4 Average 12.5 kg From 20th week 0.5kg/w Metabolic changes

14. Recommended daily dietary allowance 2500 kcal 60 gr protein Vitamins Minerals Fe, Ca, Mg, Zn, P, I Average 12.5 kg From 20th week 0.5kg/w Metabolic changes

15. Metabolic changes- cont • Water metabolism • Increased water retention • Fall in plasma osmolality 10mosm/kg • Induced by resetting of thirst and ADH secretion Edema

16. Metabolic changes- cont • Fat metabolism • Increased lipids • Increased lipoproteins • Increased apoliproteins • Protein metabolism • 1000 gr of protein per total pregnancy • Fetus, placenta • Uterus • breasts

17. Theology Ensure continuous glucose supply to fetus Pregnant woman state Woman’s fuel switch Glu > Lipids Accelerated starvation Metabolic changes- contCarbohydrate metabolism

18. Alterations Fasting hypoglycemia Postprandial hyperglycemia Hyper-insulinemia Causes Increased insulin response to Glu Reduced peripheral uptake of Glu Suppressed glucagon response Theology Ensure continuous glucose supply to fetus Metabolic changes- contCarbohydrate metabolism - cont

19. Hematological changes • Blood volume increase 45% • From 1st tr onwards • Plasma increase 50% • RBC increase 30% • Result in “physiologic” anemia • Why? • To meet demands of enlarged uterus • To protect mother from impaired venous return • To safeguard from blood loss due to parturition

20. Hematological changes – contRBC & Hb • Elevated erythropoietin • Shorter life span of RBC • Elevated reticulocytes • “physiologic” anemia: • Normal Hb >11 g/dL • Severe anemia if <10 g/dL

21. Hematological changes – contRBC & Hb - cont • Iron • Total iron requirement during pregnancy 1 gr • Daily Iron requirement 7 mg/day

22. Hematological changes – contWBC & Plt • WBC • Increase up to 16,000-20,000 • Mainly because of neutrophyls • Platelets • Plt count decrease, but stay in normal range • 7% gestational thrombocytopenia • Constant MPV • Constant reticulated plt • Decreased plt activation during pregnancy • Increased plt activation towards delivery

23. Elevated fibrinogen & factor VIII Acquired functional resistance to activated protein C Decrease in protein S Antithrombin III levels unchanged Hematological changes – contcoagulation - cont

24. Hematological changes – contcoagulation - cont • Increased tendency to thrombosis: • Physiologic thrombophilia • Obstruction of venous return by uterus and venous atonia by progesterone

25. Cardiovascular systemheart • 5th week onward, max 32nd week • Increased cardiac output • Increased heart rate 10 b/min • No change in inotropic effect • Left & upward displacement of apex (ECG) • Increased stroke volume

26. Cardiovascular systemcirculation • 5th week onward, max 32nd week • Decreased systemic & pulmonary resistance • Decrease in blood pressure S>D • Supine hypotension syndrome • Influenced by: • Renin, Angiotensin • PG • Endothgelin

27. Respiratory system • No change in respiratory rate • Increase in : • Tidal volume • Minute respiratory volume • Minute oxygen uptake

28. Respiratory system- cont • Diaphragm rises ~4 cm • Unchanged Po2, slightly decreased Pco2 • Physiologic dyspnea (awareness of breathing) • Tidal volume & lowered Pco2

29. Urinary system • Increased kidney size by 1.5 cm • Increased GFR & renal plasma flow • By 50% • 2nd trimester onwards • Physiologic gucosuria • Increased GFR • impaired tubular reabsorptive capacity for Glu • Physiologic proteinuria • Increased GFR • Up to 300 mg/24 h collection

30. Urinary system -cont • Hydronehprosis & hydroureter • Rt > lt in 90% of pregnant women • Cushioning of lt urter by sigmoid colon • Compression of rt ureter by dextrorotated uterus • Progesterone action • Bladder • Increase in urinary incontinence • Progesterone • Uterine pressure

31. Gastrointestinal tract • Delayed gastric emptying • Mechanical & hormonal • Pyrosis • Gastric reflux • Gestational gingivitis • Constipation • Hemorrhoids • constipation

32. Gastrointestinal tractLiver & gallbladder • Liver • Increased alk phosphat • Placental • Other tests unchamged • Gallbladder • Impaired contraction • Stasis • Increased prevalence of stones

33. Endocrine systemthyroid • Enlargement of thyroid • Due to increased vascularity • Increased thyroxin binding globulin • Decreased clearance • Due to Estrogen • Total T4 & T3 rise up to 20 w % plateaus but within normal range • Free T4 & T3 unchanged • Normal TSH within normal range

34. Hyperemesis • Morning sickness • 80% up to 14 w • Unknown etiology • m/p hormonal • Hyperemesis • persistent vomiting, • dehydration, ketosis, • electrolyte disturbances, • weight loss (> 5%) • Gastric electrical dysrhythmia • Elevated TSH

35. Musculoskeletal system • Lordosis • Muscular weakness • Low back pain

36. Eyes • Decreased intraocular pressure • Corneal sensitivity • Krukenberg spindles • Brownish-red pigmentation of posterior surface of cornea • Unaffected visual function

37. CNS • Problems with: • Concentration • Attention • Memory • Most pregnant women report some memory disturbance • Decline in : • Explicit memory • Implicit memory • Working memory

38. Underlying causesof memory impairment in pregnancy • Elevated progesterone • Glucocorticoids • Plasma neurotransmitters • Larger erythrocytes • Lurie S, Piper I, Gordon Y, Reprod Sciences 2005 • Cultural stereotypes

39. CNS- cont • Mood disturbance • depression • stress • anxiety • Sleep difficulty • Frequent awakenings • Reduced sleep efficiency

40. תודה על ההקשבה!!