POM II - Physiological Changes in Pregnancy - Exam 5

Placenta

essential for normal fetal growth/development and maintenance of healthy pregnancy

Placenta Functions

-prevents rejection of fetal allograft

-enables respiratory gas exchange

-transports nutrients

-eliminates fetal waste products

-secretes peptide and steroid hormones that regulate maternal metabolism and fetal growth and development

Glycogen Synthesis

stores as energy reserve

Cholesterol Synthesis

high fetal demands for cholesterol (used for energy) and placental production of progesterone and estrogen

Protein Metabolism

protein production for growth needs of fetus

Lactate Metabolism

-lactate produced in large quantities by placenta

-placenta is efficient at removing lactate

Peptide Hormones

-Human chorionic gonadotropin

-human placental lactogen

-insulin-like growth factors

-corticotropin releasing hormone

-vascular endothelial growth factor

-placental growth factor

Steroid Hormones

-progesterone

-estrogens

-glucocorticoids

Human Chorionic Gonadotropin

maintains endocrine activity of the corpus luteum (synthesis of progesterone)

hCG levels

-detected in maternal serum as early as day 8 after conception

-max level reached at week 8 of gestation

-by week 13, the level reaches a low steady state

Human Placental Lactogen

-principle action: increase supply of glucose to the fetus by decreasing maternal stores of fatty acids

-accomplished by altering maternal secretion of insulin

Insulin-like growth factors

regulates growth of placenta and fetus

corticotropin-releasing hormone

-produced by placenta and released into bloodstream

-travels to anterior pituitary to stimulate release of ACTH, which travels to adrenal cortex to stimulate release of cortisol

Vascular Endothelial Growth Factor/Placental Growth Factor

associated with angiogenesis

Progesterone Repro Effects

-increase in secretory activity of endometrium

-decrease uterine contractility

-inhibits ovulation

-stimulation of alveolar development in breasts

Progesterone Extra-genital Effects

-elevation of basal body temp

-increased sensitivity of respiratory center to CO2

-decreased smooth muscle activity

-increased excretion of Na+

-increased production of aldosterone

-neuroendocrine/behavioral effects

Estrogen Repro Effects

-increase in growth of endometrial glands and stroma

-increase in number and size of myometrial cells

-increase in myometrial contractile elements

-increase blood flow to uterus

-inhibits ovulation

-promotes ductal development of breasts

Estrogen Extra-Genital Effects

-Increased blood volume

-Increased HR, stroke volume, and cardiac output

-decrease PVR

-renal retention of Na+

-Increase production of globulin

-increase in fibrinogen

-Softening of fibrous connective tissue

Relaxin

-produced primarily by the corpus luteum

-decidua (endometrium during pregnancy)

-Placenta

Relaxin Effects

-softening of cervix; enhances cervical ripening

-softening of the ligaments of the symphysis pubis in preparation for labor and delivery

-in early pregnancy inhibits contractions of uterine wall

-relaxes mother's blood vessels

Major Hemodynamic Changes

-increased cardiac output (40-50%) d/t increased HR and increased stroke volume

-reduction in systemic vascular resistance

-reduction in systemic blood pressure for first 24-28 wks, gradual return to nL

CV Flow Changes

-increased S2 split with inspiration

-distended neck veins

-systolic ejection murmur

-diastolic murmur is NOT normal

-S3 gallop

Strenuous Exercise

can divert blood flow to large muscles -> uteroplacental hypoperfusion -> less O2 to fetus

Hematologic Changes

-Expansion of plasma volume and RBC mass starts at 4 weeks, peaks at 28-24 weeks

-physiologic anemia d/t plasma volume expansion

-hypercoagulable state

-venous stasis d/t uterine pressure on great veins of LE

-mild increase in WBC

-mild thrombocytopenia

6-8 wks pp

pregnancy-related hematologic states gradually return to baseline ___________

dyspnea

what is a common pulmonary change in pregnancy?

Dyspnea Causes

-physiologic anemia of pregnancy

-elevation of diaphragm and ribcage

-decreased FRC

-increased ventilation and resp drive

-resp alkalosis and increased arterial O2 tension

-hyperemia of upper respiratory mucosa

Pulm Concerning Symptoms

-sudden onset

-cough

-wheezing

-rales

-chest pain

-fever

-hemoptysis

asthma

what is the most common underlying pulmonary disorder in pregnancy?

Sudden-onset dyspnea causes

-PE

-Cardiac dz

-Upper airway obstruction

-spontaneous PTX

Renal Changes

-kidney volume increases by up to 30%

-GFR and renal blood flow increase markedly -> physiologic fall in serum creatinine

-urinary frequency, incontinence, nocturia common

-hydronephrosis and hydroureter are common

GERD

-30-80% of pregnant patients

-d/t decreased lower esophageal pressure

Gastric Aspiration

-pregnant pts are predisposed

-d/t increased intraabdominal pressure and relaxation of LES

-at highest risk during labor or soon after delivery

GI Labs

-Remain NL: AST/ALT, bili, fasting bile acid, amylase

-reduce: albumin, GGT

-increased: lipids, alk phos

Gallbladder Changes

volume and lithogenicity are increased

GI Symptoms Pregnancy

-Nausea (80%), vomiting (50%)

-Bloating and constipation common

-fecal incontinence and flatus more common

-hemorrhoids common

GI urgent consult

-gallstone

-pancreatitis

-appendicitis

-cholelithiasis with cholecystitis

-acute hepatitis

Endocrine Changes

-adrenal and pancreas glands not frequently affected

-anterior lobe of pituitary gland enlarges and becomes more vascular

-maternal physiology during pregnancy significantly affected by placental hormones; affects glucose and lipid metabolism

-serum prolactin generally increases, peaking at delivery

Thyroid Changes

-maternal iodine needs increase d/t increased metabolic function of thyroid gland

-increased thyroid binding globulin (d/t higher estrogen) -> increased total T3 and T4

-Free T3 and T4 remain the same

-Thyroid size remains the same -> always investigate a goiter

Hypothyroidism in Pregnancy

-optimize therapy preconception

-higher levothyroxine needs as early as 5 wks, plateaus 16-20 wks

-most women will need a 30-50% increase in levo to hit goals

-avoid radioactive iodine in pregnancy

Trimester-specific TSH Goals

-First Trimester: 0.1-2.5

-Second Trimester: 0.2-3.0

-Third Trimester: 0.3-3.0

Hyperthyroidism in Pregnancy

-thyrotoxicosis -> PTU tx in 1st semester; convert to methimazole for remainder of pregnancy

-therapeutic target for free T4 level is upper limit of normal reference range

-TSH levels generally stay suppressed even with adequate tx

-avoid radioactive iodine in pregnancy

MSK Changes

-lordosis, joint laxity

-low back pain is common

-leg cramps common

-CTS, De Quervain's

-Pelvic Girdle Pain

Hyperpigmentation

-typically nipples/areola, axillae, genitalia, perineum, anus, inner thighs, neck

-scars, freckles, and lentigines may also darken

-Linea nigra (darkening of linea alba)

-melasma (up to 75% of women)

Vascular Changes

-spider telangiectasias

-palmar erythema

-varicosities (saphenous, vulvar, hemorrhoidal) d/t increased blood volume and venous pressure in femoral and pelvic vessels from enlarging uterus

-supportive tx: leg elevation, compression stockings, exercise, avoid prolonged standing

Pyogenic Granulomas

tend to occur in 1st half of pregnancy, often in anterior mandibular or maxillary gingiva

Striae Gravidarum

-d/t connective tissue changes

-prominent on abdomen, breasts, thighs

-could be on lower back, buttox, upper arms

-usually fade PP, but do not disappear

-no effective method of prevention or treatment

Skin Growths

-skin tags may form during 2nd half of pregnancy

-existing growths may enlarge

-examine concerning nevi histologically

Pruritus

-can be flare of related d/o present prior to conception

-pregnancy-specific dermatoses

-scalp, anus, vulva, abdominal skin (3rd tri)

Hair Changes

-increased hirsutism

-temporary period of loss of hair is common PP

Nail Changes

-grow faster

-may be softer/brittle, have grooves, etc

Mucosal Changes

-most pregnant women notices gingival changes or gingivitis

-hyperemia of mucous membranes of nose/sinuses may occur

Breast Changes

-Tenderness common; mastodynia

-estrogen stimulates growth of breast duct cells, generates secretion of prolactin

-progesterone stimulates glandular growth

-montgomery tubercles become more pronounced

-skin on/around nipples can darken; nipples enlarge

-veins may be more visible

Vaginal Changes

-increased vascularity

-increased thickness of mucosa

-acidic pH

-increased vaginal discharge

Chadwick's Sign

-bluish discoloration of vulva, vagina, and cervix, resulting from increased blood flow

-observed beginning at approx 8-12 wks of gestation

Goodell's Sign

softening of cervix

Hegar's Sign

softening of lower uterine segment

Cervical Ectropion

-eversion of endocervix, exposing columnar epithelium

-prone to light bleeding when touched

-coitus, speculum or bimanual exam, cervical specimen obtained, etc