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Maternal physiology Sindhu Srinivas, MD, MSCE Division of Maternal Fetal Medicine.

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Presentation on theme: "Maternal physiology Sindhu Srinivas, MD, MSCE Division of Maternal Fetal Medicine."— Presentation transcript:

1 Maternal physiology Sindhu Srinivas, MD, MSCE Division of Maternal Fetal Medicine

2 Goals To understand the normal changes associated with pregnancy

3 Body Water TBW increases from 6.5L to 8.5L TBW increases from 6.5L to 8.5L At term water content of fetus, placenta and AF is 3.5L At term water content of fetus, placenta and AF is 3.5L BV, PV, RBC, extravascular, intracellular BV, PV, RBC, extravascular, intracellular Pregnancy is a condition of chronic volume overload Pregnancy is a condition of chronic volume overload Water retention exceeds Na retention-decreased plasma osmolality (Na dec by 3-4) Water retention exceeds Na retention-decreased plasma osmolality (Na dec by 3-4) To recognize physiologic and pathologic states during pregnancy

4 Hematology – Blood volume Increases progressively from 6 to 8 weeks’ gestation Increases progressively from 6 to 8 weeks’ gestation maximum volume at 32 weeks - 45% increase maximum volume at 32 weeks - 45% increase possibly due to estrogen stimulation of renin- angiotensin-aldosterone system possibly due to estrogen stimulation of renin- angiotensin-aldosterone system (Inc Prog, NO->Dec SVR->Dec MAP->Inc Na retention)

5 Hematology – RBC mass  Red blood cell mass increases by cc by term  Increased production  Possibly hormonally mediated

6 Hematology - Iron Maternal requirement is 1000mg Maternal requirement is 1000mg normal pregnant woman needs to absorb about 3.5 mg/day of iron normal pregnant woman needs to absorb about 3.5 mg/day of iron the goal of iron supplementation is to prevent maternal iron deficiency the goal of iron supplementation is to prevent maternal iron deficiency iron is actively transported to the fetus iron is actively transported to the fetus

7 Hematologic changes IMPLICATIONS IMPLICATIONS The increase in plasma volume and rbc mass translates into a 45% increase in circulating blood volume The increase in plasma volume and rbc mass translates into a 45% increase in circulating blood volume may protect from hemodynamic instability may protect from hemodynamic instability may serve to dissipate fetal heat production and provide increase renal filtration may serve to dissipate fetal heat production and provide increase renal filtration physiologic anemia of pregnancy physiologic anemia of pregnancy may function to decrease blood viscosity may function to decrease blood viscosity may improve intervillous perfusion? may improve intervillous perfusion?

8 Hematology LEUKOCYTES LEUKOCYTES Peripheral wbc rises progressively during pregnancy Peripheral wbc rises progressively during pregnancy 1st ∆ – mean 9500/mm3 ( ,000) 1st ∆ – mean 9500/mm3 ( ,000) 2nd and 3rd ∆ – mean 10,500 ( ,000) 2nd and 3rd ∆ – mean 10,500 ( ,000) Labor – may rise to 20-30,000 Labor – may rise to 20-30,000 Rise is due to increase in pmns (demargination) Rise is due to increase in pmns (demargination) PLATELETS PLATELETS Platelets experience a progressive decline but should remain within normal range Platelets experience a progressive decline but should remain within normal range Likely due to increased destruction Likely due to increased destruction

9 Hematology COAGULATION FACTORS COAGULATION FACTORS Increased levels Increased levels Fibrinogen (Factor I) Fibrinogen (Factor I) Factors VII through X Factors VII through X No change in prothrombin (Factor II), Factors V and XII No change in prothrombin (Factor II), Factors V and XII Decline in platelet count, Factors XI and XIII Decline in platelet count, Factors XI and XIII Bleeding time and clotting time are unchanged in normal pregnancy Bleeding time and clotting time are unchanged in normal pregnancy

10 Cardiovascular – Cardiac output Maternal cardiac output increases about 30-50% during pregnancy (mean 33%) Maternal cardiac output increases about 30-50% during pregnancy (mean 33%) pregnancy maximum of 6 L/min pregnancy maximum of 6 L/min CO remains maximal until delivery CO remains maximal until delivery Earliest rise in CO is due to increase in SV Earliest rise in CO is due to increase in SV As pregnancy progresses As pregnancy progresses Gradual increase in mat HR (15-20 bpm rise) Gradual increase in mat HR (15-20 bpm rise) SV declines to near non-pregnant levels SV declines to near non-pregnant levels increase HR is what maintains the elevated CO increase HR is what maintains the elevated CO

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12 Cardiovascular – Cardiac output CO is position dependent CO is position dependent Lower when supine Lower when supine IVC compression by the uterus reduces venous return to the heart IVC compression by the uterus reduces venous return to the heart At weeks, there is a 25-30% fall in CO when turning from the side to the back At weeks, there is a 25-30% fall in CO when turning from the side to the back Fall in CO is compensated by a rise in peripheral vascular resistance Fall in CO is compensated by a rise in peripheral vascular resistance supine hypotensive syndrome (1-10% patients) supine hypotensive syndrome (1-10% patients)

13 Cardiovascular – Cardiac output Distribution of CO Distribution of CO First trimester and non-pregnant state First trimester and non-pregnant state Uterus receives 2-3% Uterus receives 2-3% By term By term Uterus receives 17% Uterus receives 17% Breasts 2% Breasts 2% Reduction of the fraction of CO going to the splanchnic bed and skeletal muscle Reduction of the fraction of CO going to the splanchnic bed and skeletal muscle CO to the kidneys, skin, brain and coronary arteries does not change CO to the kidneys, skin, brain and coronary arteries does not change

14 Cardiovascular – Arterial BP BP varies with position BP varies with position Peripheral vascular resistance falls during pregnancy Peripheral vascular resistance falls during pregnancy Progesterone’s smooth muscle relaxing effect Progesterone’s smooth muscle relaxing effect ?heat production by the fetus  vasodilatation ?heat production by the fetus  vasodilatation The reduction in PVR may lead to a progressive fall in systemic arterial bp during the first 24 weeks of pregnancy The reduction in PVR may lead to a progressive fall in systemic arterial bp during the first 24 weeks of pregnancy Gradual rise after 24 weeks  non-pregnant levels by term Gradual rise after 24 weeks  non-pregnant levels by term

15 Cardiovascular – Venous system Venous compliance increases during pregnancy Venous compliance increases during pregnancy decrease in flow velocity and stasis decrease in flow velocity and stasis ?progesterone effects on smooth muscle ?progesterone effects on smooth muscle Forearm venous pressure increases by 40-50% Forearm venous pressure increases by 40-50% Calf venous pressures are always higher Calf venous pressures are always higher due to the enlarging uterus due to the enlarging uterus

16 Cardiovascular - LV function Left ventricular dimensions and volume increase during pregnancy Left ventricular dimensions and volume increase during pregnancy most parameters of LVF are the same as in the non- pregnant state most parameters of LVF are the same as in the non- pregnant state Ejection fraction, rate of internal diameter shortening, percentage of fractional shortening, and ventricular wall thickness Ejection fraction, rate of internal diameter shortening, percentage of fractional shortening, and ventricular wall thickness Bottom line: preservation of myocardial function Bottom line: preservation of myocardial function

17 Signs and Symptoms of Normal Pregnancy Symptoms Symptoms reduced exercise tolerance reduced exercise tolerance dyspnea dyspnea Signs Signs peripheral edema peripheral edema distended neck veins distended neck veins point of maximal impulse displaced to the left point of maximal impulse displaced to the left

18 Signs and Symptoms of Normal Pregnancy Auscultation Auscultation increased splitting of the first and second heart sound increased splitting of the first and second heart sound S3 gallop S3 gallop SEM along the left sternal border SEM along the left sternal border Continuous murmurs Continuous murmurs

19 Signs and Symptoms of Normal Pregnancy CXR CXR straightening of left heart border straightening of left heart border heart position more horizontal – may appear as cardiomegaly on cxr heart position more horizontal – may appear as cardiomegaly on cxr increased vascular markings in lungs increased vascular markings in lungs ECG ECG left axis deviation left axis deviation non-specific ST-T wave changes non-specific ST-T wave changes

20 Cardiovascular - Labor First stage of labor: 12-31% rise on CO due to an increase in SV First stage of labor: 12-31% rise on CO due to an increase in SV Second stage of labor: 34% increase in CO Second stage of labor: 34% increase in CO Not only pain-related Not only pain-related UCs result in the transfer of cc of blood from the uterus to the general circulation UCs result in the transfer of cc of blood from the uterus to the general circulation Enhanced venous return to the heart Enhanced venous return to the heart Increase in CO by 10-15% Increase in CO by 10-15%

21 Cardiovascular - Postpartum Immediate pp period: 10-20% rise in CO Immediate pp period: 10-20% rise in CO release of obstruction of venous return release of obstruction of venous return extracellular fluid mobilization extracellular fluid mobilization Rise in CO associated with reflex bradycardia Rise in CO associated with reflex bradycardia SV increases  this may persist for one to two weeks after delivery SV increases  this may persist for one to two weeks after delivery

22 QUESTION During which of the following states is the blood pressure lowest? During which of the following states is the blood pressure lowest? a) First trimester b) Second trimester c) Third trimester d) Non pregnant

23 QUESTION Increased cardiac output immediately postpartum is due to: Increased cardiac output immediately postpartum is due to: a) Increased HR b) Release of obstruction of venous return c) Reduced mobilization of extracellular fluid d) Reduced stroke volume

24 Respiratory system UPPER RESPIRATORY TRACT UPPER RESPIRATORY TRACT Hyperemic mucosa of nasopharynx Hyperemic mucosa of nasopharynx Estrogen-mediated Estrogen-mediated nasal stuffiness and epistaxis nasal stuffiness and epistaxis Polyposis of nose and sinuses may occur and regress after delivery Polyposis of nose and sinuses may occur and regress after delivery “chronic cold” “chronic cold” MECHANICAL CHANGES MECHANICAL CHANGES Configuration of thoracic cage changes early in pregnancy Configuration of thoracic cage changes early in pregnancy Increase in subcostal angle, transverse diameter and circumference of chest Increase in subcostal angle, transverse diameter and circumference of chest With advancing gestation, the level of diaphragm is pushed up With advancing gestation, the level of diaphragm is pushed up

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26 Changes in pulmonary function tests during pregnancy Serial measurements of lung volume compartments during pregnancy. Functional residual capacity decreases approximately 20 percent during the latter half of pregnancy, due to a decrease in both expiratory reserve volume and residual volume. Redrawn from Prowse, CM, Gaensler, EA, Anesthesiology 1965; 26:381.

27 Respiratory system LUNG VOLUME AND PULMONARY FUNCTION LUNG VOLUME AND PULMONARY FUNCTION 30-40% increase in tidal volume (Amount of air I and E with each breath) 30-40% increase in tidal volume (Amount of air I and E with each breath) 30-40% increase in minute ventilation (likely P4 mediated) 30-40% increase in minute ventilation (likely P4 mediated) ERV falls by 20% ERV falls by 20% Vital capacity and inspiratory reserve volume remain unchanged Vital capacity and inspiratory reserve volume remain unchanged

28 Respiratory system LUNG VOLUME AND PULMONARY FUNCTION LUNG VOLUME AND PULMONARY FUNCTION Respiratory rate is unchanged Respiratory rate is unchanged Due to elevation of the diaphragm Due to elevation of the diaphragm Total lung volume decreases (diaphragm) by 5% Total lung volume decreases (diaphragm) by 5% Residual volume decreases (RV) by 20% Residual volume decreases (RV) by 20% FRC is reduced 20% FRC is reduced 20% No change in FEV1 or the ratio of FEV1 to forced vital capacity No change in FEV1 or the ratio of FEV1 to forced vital capacity

29 Respiratory system GAS EXCHANGE GAS EXCHANGE Minute ventilation rises 30-40% by late pregnancy Minute ventilation rises 30-40% by late pregnancy O2 consumption increases only 15-29% O2 consumption increases only 15-29% Results in higher PAO2 (alveolar) and PaO2 (arterial) Results in higher PAO2 (alveolar) and PaO2 (arterial) Normal PaO2: mmHg Normal PaO2: mmHg Fall in PACO2 and PaCO2 levels Fall in PACO2 and PaCO2 levels Normal PaCO2 level: mmHg Normal PaCO2 level: mmHg Increases gradient of CO2 facilitating transfer from fetus to mother Increases gradient of CO2 facilitating transfer from fetus to mother Arterial pH remains unchanged Arterial pH remains unchanged Increased bicarbonate excretion via kidneys Increased bicarbonate excretion via kidneys

30 Respiratory system DYSPNEA OF PREGNANCY DYSPNEA OF PREGNANCY Common complaint Common complaint 60-70% of patients 60-70% of patients late first or early second trimester late first or early second trimester Likely due to various factors Likely due to various factors reduced PaCO2 levels reduced PaCO2 levels awareness of increased tidal volume of pregnancy awareness of increased tidal volume of pregnancy

31 QUESTION Which of the following is increased in pregnancy? Which of the following is increased in pregnancy? a) FRC b) ERV c) RV d) TV

32 Renal system ANATOMY ANATOMY Kidney enlargement Kidney enlargement increased renal vascular and interstitial volume, R>L increased renal vascular and interstitial volume, R>L Ureteral and renal pelvis dilatation by 8 weeks Ureteral and renal pelvis dilatation by 8 weeks Right > left Right > left mechanical compression by uterus and ovarian venous plexus mechanical compression by uterus and ovarian venous plexus smooth muscle relaxation by progesterone smooth muscle relaxation by progesterone Implications Implications Increased incidence of pyelonephritis Increased incidence of pyelonephritis difficulty in interpreting radiographs difficulty in interpreting radiographs interference with studies interference with studies

33 Renal system RENAL HEMODYNAMICS RENAL HEMODYNAMICS Effective renal plasma flow (ERPF) and GFR increase Effective renal plasma flow (ERPF) and GFR increase Filtration fraction falls Filtration fraction falls Returns to normal by late third Δ Returns to normal by late third Δ Endogenous creatinine clearance increases Endogenous creatinine clearance increases Begins by 5 weeks Begins by 5 weeks

34 Renal system METABOLITES METABOLITES increased GFR  decline in serum urea and creatinine increased GFR  decline in serum urea and creatinine BUN – 8-9 mg/dl by end 1 st Δ BUN – 8-9 mg/dl by end 1 st Δ Decline in serum creatinine Decline in serum creatinine 0.7 mg/dl by end 1 st Δ 0.7 mg/dl by end 1 st Δ mg/dl by term mg/dl by term Early decline in serum uric acid levels Early decline in serum uric acid levels nadir at 24 weeks nadir at 24 weeks same as nonpregnant level at end of pregnancy due to increased reabsorption of urate same as nonpregnant level at end of pregnancy due to increased reabsorption of urate

35 Renal system SALT AND WATER METABOLISM SALT AND WATER METABOLISM Plasma osmolality begins to decline by 2 weeks after conception Plasma osmolality begins to decline by 2 weeks after conception reduction in serum sodium and other anions reduction in serum sodium and other anions Sodium loss during pregnancy Sodium loss during pregnancy 50% rise in GFR 50% rise in GFR Progesterone: natriuresis Progesterone: natriuresis Renal tubular reabsorption of Na+ increases (aldosterone, estrogen and deoxycorticosterone) Renal tubular reabsorption of Na+ increases (aldosterone, estrogen and deoxycorticosterone) Sodium homeostasis Sodium homeostasis

36 Renal system NUTRIENT EXCRETION NUTRIENT EXCRETION Increase in glucose excretion Increase in glucose excretion 1-10 g glucose excretion per day 1-10 g glucose excretion per day Due to 50% increase in GFR Due to 50% increase in GFR implications implications inability to use urine glucose inability to use urine glucose susceptibility of pregnant women to UTI susceptibility of pregnant women to UTI Increase in amino acid excretion during gestation Increase in amino acid excretion during gestation no increased protein loss ( mg/24 hr) no increased protein loss ( mg/24 hr) Increased urinary loss of folate and vitamin B12 Increased urinary loss of folate and vitamin B12

37 QUESTION All of the following are increased in pregnancy except: All of the following are increased in pregnancy except: a) Renal plasma flow b) GFR c) Serum creatinine d) Tubular sodium resorption

38 Gastrointestinal - Appetite Increase early 1st Δ Increase early 1st Δ Increase intake 200 kcal by end 1st Δ Increase intake 200 kcal by end 1st Δ RDA: 300 kcal/day during pregnancy RDA: 300 kcal/day during pregnancy Sense of taste may be blunted Sense of taste may be blunted Pica Pica check for poor weight gain and refractory anemia check for poor weight gain and refractory anemia South - clay or starch (laundry or cornstarch) South - clay or starch (laundry or cornstarch) UK – coal UK – coal Also soap, toothpaste and ice pica Also soap, toothpaste and ice pica

39 Gastrointestinal - Mouth Unchanged pH or production of saliva Unchanged pH or production of saliva Saliva production is unaltered Saliva production is unaltered Ptyalism – usually in women with HEG Ptyalism – usually in women with HEG due to inability to swallow due to inability to swallow Can lose up to 1-2 L of saliva per day Can lose up to 1-2 L of saliva per day Decreasing starchy foods might help Decreasing starchy foods might help Gums – edematous and soft Gums – edematous and soft May bleed after brushing May bleed after brushing Epulis gravidarum Epulis gravidarum regress 1-2 mos after delivery regress 1-2 mos after delivery excise if persistent or excessive bleeding excise if persistent or excessive bleeding

40 Gastrointestinal - Stomach Decreased tone and motility Decreased tone and motility progesterone progesterone possibly due to decreased levels of motility possibly due to decreased levels of motility Conflicting info about delayed gastric emptying Conflicting info about delayed gastric emptying Reduced tone of the gastroesophageal junction sphincter Reduced tone of the gastroesophageal junction sphincter Increased intraabdominal pressure leads to acid reflux Increased intraabdominal pressure leads to acid reflux Lower incidence of PUD Lower incidence of PUD may be due to decreased gastric acid secretion delayed emptying, increase in gastric mucus, and protection of mucosa by prostaglandins may be due to decreased gastric acid secretion delayed emptying, increase in gastric mucus, and protection of mucosa by prostaglandins

41 Gastrointestinal - Small bowel Reduced motility of small bowel Reduced motility of small bowel increased transit time in the third trimester and postpartum increased transit time in the third trimester and postpartum Enhanced iron absorption Enhanced iron absorption as a response to increased iron needs as a response to increased iron needs

42 Gastrointestinal - Colon Constipation Constipation Mechanical obstruction by the uterus Mechanical obstruction by the uterus Reduced motility (p4) Reduced motility (p4) Increased water absorption Increased water absorption Portal venous pressure is increased Portal venous pressure is increased Dilation of gastroesophageal vessels Dilation of gastroesophageal vessels issue in those with preexisting esophageal varices issue in those with preexisting esophageal varices Dilation of hemorrhoidal veins Dilation of hemorrhoidal veins hemorrhoids hemorrhoids

43 Gastrointestinal - Gallbladder Fasting and residual volumes double in 2nd and 3rd Δ Fasting and residual volumes double in 2nd and 3rd Δ Slower rate of emptying Slower rate of emptying Biliary cholesterol saturation increases and chenodeoxycholic acid decreases Biliary cholesterol saturation increases and chenodeoxycholic acid decreases increased risk gallstone formation increased risk gallstone formation

44 Gastrointestinal - Liver Liver does not enlarge Liver does not enlarge Hepatic blood flow remains unchanged Hepatic blood flow remains unchanged CO to the liver decreases by ~35% CO to the liver decreases by ~35% Spider angiomata and palmar erythema Spider angiomata and palmar erythema elevated estrogen levels elevated estrogen levels Lab data Lab data Drop in serum albumin Drop in serum albumin Rise in serum alkaline phosphatase Rise in serum alkaline phosphatase placental production and some hepatic production placental production and some hepatic production Rise in serum cholesterol, fibrinogen, ceruloplasmin, binding proteins for corticosteroids, sex steroids, thyroid hormones, and vitamin D Rise in serum cholesterol, fibrinogen, ceruloplasmin, binding proteins for corticosteroids, sex steroids, thyroid hormones, and vitamin D No change in serum bilirubin, AST, ALT, protime and 5’ nucleotidase No change in serum bilirubin, AST, ALT, protime and 5’ nucleotidase Rise in GGT is controversial Rise in GGT is controversial

45 Gastrointestinal system NAUSEA AND VOMITING NAUSEA AND VOMITING Morning sickness complicates 70% of pregnancies Morning sickness complicates 70% of pregnancies Onset 4-8 weeks up to weeks Onset 4-8 weeks up to weeks Cause? Cause? Relaxation of smooth muscle of stomach, elevated levels of steroids and hCG Relaxation of smooth muscle of stomach, elevated levels of steroids and hCG Rx – supportive: reassurance, support, and avoiding triggers… Rx – supportive: reassurance, support, and avoiding triggers… HEG HEG weight loss, ketonemia, electrolyte imbalance and dehydration weight loss, ketonemia, electrolyte imbalance and dehydration possible renal or hepatic damage possible renal or hepatic damage IVF, antiemetics IVF, antiemetics NPO NPO continue IV continue IV

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47 Conclusion Understanding maternal physiology is crucial in understanding the changes and clinical scenarios associated in pregnancy Understanding maternal physiology is crucial in understanding the changes and clinical scenarios associated in pregnancy This knowledge will help us distinguish the physiologic and pathologic processes during pregnancy This knowledge will help us distinguish the physiologic and pathologic processes during pregnancy This knowledge will also improve patient’s education about their pregnancy This knowledge will also improve patient’s education about their pregnancy

48 Endocrine - Thyroid The normal pregnant woman is euthyroid The normal pregnant woman is euthyroid Changes in thyroid morphology and lab indices Changes in thyroid morphology and lab indices Estrogen-induced increase in TBG Estrogen-induced increase in TBG Decreased circulating extrathyroidal iodide Decreased circulating extrathyroidal iodide Thyroid enlargement usually not detected by exam Thyroid enlargement usually not detected by exam Normal thyroidal uptake of iodide Normal thyroidal uptake of iodide Serum TSH decreases early in gestation Serum TSH decreases early in gestation rises to pre-pregnancy levels by end of first Δ rises to pre-pregnancy levels by end of first Δ T4 increases early in gestation T4 increases early in gestation role of hCG stimulating the thyroid role of hCG stimulating the thyroid Rise in TBG leads to rise in total T4 and total T3 Rise in TBG leads to rise in total T4 and total T3 active hormones free T4 and free T3 are unchanged active hormones free T4 and free T3 are unchanged Free T4 is the most reliable method of evaluating thyroid function in pregnancy Free T4 is the most reliable method of evaluating thyroid function in pregnancy

49 Endocrine - Adrenal glands Expansion of the zona fasciculata Expansion of the zona fasciculata site of glucocorticoid production site of glucocorticoid production Plasma corticosteroid-binding globulin (CBG) rises Plasma corticosteroid-binding globulin (CBG) rises due to enhanced liver synthesis due to enhanced liver synthesis Free plasma cortisol rises Free plasma cortisol rises increased production and delayed clearance increased production and delayed clearance Plasma DOC (deoxycorticosterone) rises Plasma DOC (deoxycorticosterone) rises fetoplacental unit fetoplacental unit DHEAS (dehydroepiandrosterone) decreases DHEAS (dehydroepiandrosterone) decreases Testosterone is slightly elevated Testosterone is slightly elevated Increased SHBG and androstenedione Increased SHBG and androstenedione

50 Endocrine - Pancreas Hypertrophy and hyperplasia of the B cells Hypertrophy and hyperplasia of the B cells Fasting associated with accelerated starvation Fasting associated with accelerated starvation maternal hypoglycemia, hypoinsulinemia and hyperketonemia maternal hypoglycemia, hypoinsulinemia and hyperketonemia due to diffusion of glucose by the fetoplacental unit due to diffusion of glucose by the fetoplacental unit Feeding response Feeding response hyperglycemia, hyperinsulinemia, hypertriglyceridemia and reduced tissue sensitivity to insulin hyperglycemia, hyperinsulinemia, hypertriglyceridemia and reduced tissue sensitivity to insulin glucose response greater during pregnancy glucose response greater during pregnancy peripheral resistance to insulin: diabetogenic effect of pregnancy. peripheral resistance to insulin: diabetogenic effect of pregnancy. hPL and cortisol mediated hPL and cortisol mediated greater insulin resistance as the pregnancy advances greater insulin resistance as the pregnancy advances

51 Endocrine - Pancreas Fetus primarily depends on glucose Fetus primarily depends on glucose Facilitated diffusion Facilitated diffusion carrier-mediated but not energy dependent process carrier-mediated but not energy dependent process Active transport of amino acids to the fetus Active transport of amino acids to the fetus Ketones diffuse freely across the placenta Ketones diffuse freely across the placenta

52 Endocrine - Pituitary The pituitary gland enlarges in pregnancy The pituitary gland enlarges in pregnancy proliferation of chromophobe cells on the anterior pituitary proliferation of chromophobe cells on the anterior pituitary stalk remains midline stalk remains midline

53 Skin Spider angiomata (face, upper chest, and arm) and palmar erythema Spider angiomata (face, upper chest, and arm) and palmar erythema elevated estrogen levels elevated estrogen levels both regress after delivery both regress after delivery Striae gravidarum Striae gravidarum Increased eccrine sweating and sebum excretion Increased eccrine sweating and sebum excretion

54 Skin Hyperpigmentation Hyperpigmentation Melasma: “mask of pregnancy” Melasma: “mask of pregnancy” elevated e2 and p4 elevated e2 and p4 Nevi may darken, enlarge or show increased activity Nevi may darken, enlarge or show increased activity rapidly changing nevi should be excised rapidly changing nevi should be excised Hairs in telogen phase decrease in late pregnancy Hairs in telogen phase decrease in late pregnancy increases after delivery increases after delivery hair loss 2-4 mos pp hair loss 2-4 mos pp re-growth in 6-12 mos re-growth in 6-12 mos Masculinization of the skin rarely occurs Masculinization of the skin rarely occurs evaluate for possible luteomas of pregnancy (which regress after delivery) evaluate for possible luteomas of pregnancy (which regress after delivery)

55 Breasts Early change Early change tenderness, tingling and heaviness tenderness, tingling and heaviness vascular engorgement leads to enlargement vascular engorgement leads to enlargement Ductal growth due to e2 Ductal growth due to e2 Alveolar hypertrophy due to p4 Alveolar hypertrophy due to p4 Enlargement and pigmentation of areolae Enlargement and pigmentation of areolae Colostrum may be expressed later in pregnancy Colostrum may be expressed later in pregnancy Milk production Milk production E2, p4, prolactin, hPL, cortisol and insulin E2, p4, prolactin, hPL, cortisol and insulin Lactation likely due to drop in estrogen and progesterone after delivery Lactation likely due to drop in estrogen and progesterone after delivery

56 Skeleton Lordosis Lordosis keep center of gravity over the legs keep center of gravity over the legs back pain… back pain… Relaxin Relaxin relaxation of the pubic symphysis and sacroiliac joints relaxation of the pubic symphysis and sacroiliac joints facilitates vaginal delivery but may lead to discomfort facilitates vaginal delivery but may lead to discomfort Implications Implications unsteadiness of gait and trauma from falls unsteadiness of gait and trauma from falls

57 Skeleton Total serum calcium declines throughout pregnancy until weeks Total serum calcium declines throughout pregnancy until weeks due to the fall in serum albumin due to the fall in serum albumin Serum ionized calcium is constant and unchanged Serum ionized calcium is constant and unchanged “Physiologic hyperparathyroidism” “Physiologic hyperparathyroidism” increased gut absorption increased gut absorption decreased renal losses decreased renal losses no bone loss seen in bone density studies no bone loss seen in bone density studies preservation due to calcitonin? preservation due to calcitonin? Rate of bone turnover and remodeling increases throughout pregnancy Rate of bone turnover and remodeling increases throughout pregnancy twice as great at term twice as great at term

58 Eye Increased thickness of cornea due to fluid retention (contact lens intolerance) Increased thickness of cornea due to fluid retention (contact lens intolerance) Decreased intraocular pressure Decreased intraocular pressure


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