Physiology of Pregnancy Delivery Flashcards
Mechanical respiratory changes in pregnancy
chest circumference increases (5-7cm), subcostal angle increases, transverse diameter increases, level of diaphragm rises
URT changes in pregnancy
hyperemia and edema from estrogen + nasal stuffiness and epistaxis
What change in pregnancy? residual volume
diminished
What change in pregnancy? expiratory reserve
no change
What change in pregnancy? tidal volume
increases
What change in pregnancy? inspiratory reserve
diminished
What change in pregnancy? total lung capacity
reduced
Hyperventilation leads to _____ PCO2 and ____ PO2 driving the gradient at the level of placenta
decreased and increased
What change in pregnancy? minute ventilation
increase
dyspnea of pregnancy
60-70% of women complain in late first or early second trimester –> reduced pco2 levels, awareness of increased tidal volume of pregnancy
Cardiac output
sv X hr
Stroke volume
amount of blood ejected from each ventricle with a contraction
What change in pregnancy? heart
bigger on CXR, but just because of rotation
What change in pregnancy? cardiac output
increase –> 4.5 L/min to 6 L/min –> uterus gets 17% of CO –> reduction in maternal CO doesnt change except for skeletal muscle and splanchnic bed
What change in pregnancy? heart rate
increase as early as 5 weeks
T/F maternal position can impact CO
T –> compression of IVC by large term gravid uterus can decrease cardiac output by 25% if supine
What change in pregnancy? peripheral vascular resistance
decrease due to progesterone –> fall in systemic arterial pressure with nadir at about 24 weeks
Drop in _____ helps the maternal cardiovascular system accommodate the increased blood volume in pregnancy
vascular resistance
T/F diastolic ejection murmurs occur in over 90% of pregnant women due to increased cardiac output
F –> this is true of systolic murmurs…diastolic murmurs are NOT normal
What change in pregnancy? body water
increase from 6.5L to 8.5L
In pregnancy _____ exceeds Na retention decreased plasma osmolality
water retention
What change in pregnancy? Na
decreased by 3-4
What change in pregnancy? blood volume
increases from 6-8 weeks gestation
What change in pregnancy? red cell mass
increases by term
Physiologic anemia of pregnancy
plasma volume increase > rbc volume increase –> dilution –> reduce blood viscosity, increased EPO, helps in perfusion and maternal/fetal exchange
What change in pregnancy? blood viscosity
decrease due to physiologic anemia
What change in pregnancy? coagulation cascade
increase in 1, vii, viii, ix, x –> hypercoagulable and decrease in fibrinolysis
What change in pregnancy? venous flow
increased stasis + vessel wall injury + hypercoagulability –> thromboembolism risk increases
What change in pregnancy? thromboembolic risk
increase
What change in pregnancy? bleeding and clotting times
no change
What change in pregnancy? kidneys
hypertrophy + dilation of renal pelves/calyces
What change in pregnancy? ureters
dilation due to increased progesterone –> right side is more affected due to mechanical effects of uterus
What change in pregnancy? renal plasma flow
increased
What change in pregnancy? gfr
increased
What change in pregnancy? creatinine
reduced
What change in pregnancy? stomach emptying time
decreased
What change in pregnancy? GI tone
decreased –> acid reflux
What change in pregnancy? small bowel motility
decreased –> more constipation
What change in pregnancy? portal venous pressure
increased –> hemorrhoids
What change in pregnancy? gallbladder emptying
slowed –> increased cholesterol saturation –> increased stone formation
What change in pregnancy? liver
increased production of fibrinogen, binding proteins (steroids and thyroid hormone), clotting factors (7, 8, 9, 10)
What change in pregnancy? AST/ALT
no change
Hyperemesis in pregnancy
likely impact of hCG –> supportive care, ginger, vit b6, unisom, antiemetics
What change in pregnancy? caloric requirements per day
increased
gravid
woman who has been pregnant before
nullipara
women who has never completed a pregnancy beyond 20 weeks
primipara vs multipara
woman who has delivered one fetus>20 weeks vs multiple fetus > 20 weeks
“looking down” presentation
occiput anterior
“looking up” presentation
occiput posterior
Smallest dimension of babies head
suboccipitobregmatic
Round pelvis
gynecoid
Pelvis with AP>transverse
android
Pelvis with AP~transverse
anthropoid
Pelvis with AP<transverse
platypelloid
Regular uterine contractions leading to cervical dilation
labor
Which prostaglandins are involved in uterine ctx?
prostaglandins E2 and F2alpha
What causes uterine ctx?
prostaglandins E2 and F2 alpha, things that increase intracellular Ca, gap junctions, increased oxytocin receptors
What causes cervical ripening?
collagenase, elastase (metalloproteases)
In cervical effacement, collagen chains are broken down and hydrophobic glycosaminoglycans are replaced by hydrophilic _______
hyaluronic acid
Cervical smooth muscle contraction causes cervical tissue to be pulled upward and incorporated into the lower segment of the ____
corpus
Prostaglandin receptors for uterine ctx are found in _____
decidua and myometrium
Oxytocin gene is upregulated by ____
estrogen
Oxytocin receptors for uterine ctx are found in ____
myometrium, fetal amnion, decidua
Term
> 37 weeks
Mean duration of pregnancy
40 weeks from first day of last menstrual period
Stages of labor
1: closed-fully dilated, 2: fully dilated-delivery, 3: placenta
2 phases of stage 1 labor
latent and active
Latent phase
onset of labor with slow cervical dilation to ~4cm and variable duration
Active phase
faster rate of cervical change, regular uterine contractions
Round pelvis
gynecoid
Pelvis with AP>transverse
android
Pelvis with AP~transverse
anthropoid
Pelvis with AP<transverse
platypelloid
Regular uterine contractions leading to cervical dilation
labor
Which prostaglandins are involved in uterine ctx?
prostaglandins E2 and F2alpha
What causes uterine ctx?
prostaglandins E2 and F2 alpha, things that increase intracellular Ca, gap junctions, increased oxytocin receptors
What causes cervical ripening?
collagenase, elastase (metalloproteases)
In cervical effacement, collagen chains are broken down and hydrophobic glycosaminoglycans are replaced by hydrophilic _______
hyaluronic acid
Cervical smooth muscle contraction causes cervical tissue to be pulled upward and incorporated into the lower segment of the ____
corpus
Prostaglandin receptors for uterine ctx are found in _____
decidua and myometrium
Oxytocin gene is upregulated by ____
estrogen
Oxytocin receptors for uterine ctx are found in ____
myometrium, fetal amnion, decidua
Term
> 37 weeks
Mean duration of pregnancy
40 weeks from first day of last menstrual period
Stages of labor
1: closed-fully dilated, 2: fully dilated-delivery, 3: placenta
2 phases of stage 1 labor
latent and active
Latent phase
onset of labor with slow cervical dilation to ~4cm and variable duration
Active phase
faster rate of cervical change, regular uterine contractions
0 station
after engagement of the fetus with the pelvis, can palpate for presentation right below ischial spines
Passive response of fetal head to soft tissues of the pelvis
flexion
Downward passage of fetus presenting part
descent
T/F there is an increase in cardiac output during labor
T (especially in second stage of labor) –> pain + uterine ctx transfer blood from uterus to general circulation –> increases venous return to heart
Shoulder dystocia
anterior shoulder stuck behind mother’s pelvic bone –> usually with large baby –> can stretch brachial plexus