exam 1 - phys pregnancy Flashcards
A 25 yo healthy gravida 1, para 0, last menstrual period (LMP) 8 weeks ago is seeing you for her first prenatal appointment. This was an unplanned pregnancy but she is happy about it.
She complains of near daily nausea and states she is vomiting several times per week. She also feels “as if I have a cold all of the time, and I am tired a lot.” She states she has frequent urination but denies any vaginal bleeding, abdominopelvic pain, or dysuria.
She complains of near daily nausea and states she is vomiting several times per week. She also feels “as if I have a cold all of the time, and I am tired a lot.” She states she has frequent urination but denies any vaginal bleeding, abdominopelvic pain, or dysuria.
You examine the patient and reassure her about her symptoms. You counsel her about signs and symptoms related to the physiologic changes of pregnancy. She states, “I feel better because I understand why these things are happening to me. Thank you.”
physiology of pregnancy
-multiple and dramatic changes in maternal physiology
-allow pt to accommodate development of
embryo (prior to 14 weeks), and later, the fetus (after about 14 weeks)
-help to inform us why a pt with significant ds may become ill, even to point of death, during pregnancy due to underlying illness
maternal mortality
-US has highest maternal mortality rate of any developed country in the world
-NY- 21.7 mother mortality per 100,000 births
-non-hispanic black (69.9) > hispanic > non-hispanic white (26.6)
-black mothers have more than double mortality than white mothers
-allostatic load (weathering)- physiologic stress of being a black women in the US
-(not being tested on the photos)
relaxin
-Cardiovascular changes -> most dramatic changes during pregnancy
-MSK attachments are loosened or relaxed due to secretion of relaxin -> secreted by placenta
-this happens to enable to the deliver of the fetal head
-Due to relaxin:
-expansion of the thoracic cavity anterior and posterior bc diaphragm moves up
-position of heart changes -> displaced up and left
-apex of heart moves laterally due to increasing ht of diaphragm
-increase in ventricular muscle mass due to increase CO
Cardiac output
-Starling’s law: CO = SV x HR
-40% increase of blood volume during pregnancy -> it has to go somewhere
-Thus, CO must increase 40% in order for the pt to survive this increase in volume
-In 1st half of pregnancy- increase in CO is due to increased SV
-In 2nd half of pregnancy- increase in CO is due to increased HR -> SV returns to normal (76 -> 88 (not 130))
-Increase in CO peaks at 32 weeks
cardiovascular PE
-Increase in split S2
-Systolic ejection murmur (turbulence from extra blood) heard best at left sternal border present in >90% of gravid patients
-Other changes:
-Nonspecific T wave changes
-Flipped T waves
-Left axis deviation
-All are due to change in heart position in thorax due to relaxin
blood pressure changes
-changes due to systemic vascular resistance changes from
-Progestational effect
-Arteriovenous shunting to uterus and placenta
-Increased levels of prostaglandins, nitric oxide, etc.
-vasodilated, dehydrated
-BP changes throughout pregnancy
-1st trimester- normal
-2nd trimester- decreased -> increase risk of syncope
-3rd trimester- Returns to normal or may increase mildly
-Largely due to decrease in systemic vascular resistance
respiratory changes
-“i feel like i have cold all the time”
-Estrogen and progesterone receptors in medulla and hypothalamus cause feeling of nasal congestion -> may persist entire pregnancy
-tx- afrin (not systemic)
-diaphragm rises about 4 cm -> reduces residual lung volume
-inspiratory capacity increases by about 5-10% (bc relaxin)
-Total lung capacity- no change
-Forced vital capacity- no change
-Tidal volume and resting minute ventilation both increase -> ventilation increased due to respiratory alkalosis
-RR = normal
-!!Respiratory rate is generally unchanged
dyspnea and hypocapnia
-pts may feel dyspneic
-Gravid pts are more sensitive to CO2 -> do not tolerate it as well
-dyspnea due increasing fundal ht and decreased lung compliance
-PE findings: none
-Lab findings: respiratory alkalosis on ABG due to relative hypocapnia
-Mimics ABG finding in early, non-catastrophic pulmonary embolus
dilutional anemia
-Increase of 40% in blood volume (1600 cc on average)
-Of this:
-Approx 300 cc (19%) are RBCs
-Approx 1300 cc (81%) is plasma
-> dilutional anemia of pregnancy
-plasma > RBC
-like dumping a bucket of water in your veins
-not something to worry about
clotting factors
-fibrinogen and fibrin split products increase by 50%!!!! -> ob hemorrhage is common
-if a OB has low fibrinogen -> BAD
-factors 7,8, and 10 increase by 50%
-factors 2,5, and 12 are unchanged
-activated protein C and protein S decrease
dilation of renal system and changes in ureteral peristalsis
-increased wt and size of uterus -> compresses kidneys and ureters -> renal pelvis and calyces dilate
-fluid, uterus, placenta each 1lbs, baby is 7 lbs -> compression
-bilateral hydronephrosis
-Renal plasma flow increases by 75%
-Increase in GFR increases by 40%
-Progesterone effect causes decrease in ureteral peristalsis
-Urinary stasis causes -> increase in asymptomatic! bacteriuria
-Urinary incontinence is common at term and during the puerperium
-increase risk of pyelonephritis -> high fever but asymptomatic -> ceftriaxone
a good guess for stats…
-40%
-if not, its 80%
changes in renin-angiotensin-aldosterone
-RAAS components increase dramatically due to ESTROGEN effects
-Plasma renin increases by 1000%
-Plasma angiotensin increases by 500%
-!!However, most pts are resistant to these changes!! -> do not become hypertensive
-Some pts with underlying renal ds or predisposition to HTN disorders of pregnancy will develop HTN
-Renal function test values (BUN, creatinine) decrease in pregnancy
-resistant to their own RAAS -> no HTN (most) -> 20% do
nausea and vomiting of pregnancy
-80% of pts develop some degree of N/V
-Generally improves by 15 weeks
-Possibly due to E2 and/or HCG
-Increased progesterone causes decreased peristalsis throughout GI -> constipation
-also iron supplements, also baby compressing
