Flashcards in Physiology 2 Deck (93):
Weeks of full pregnancy?
40 from first day LMP
Weeks for viability of baby?
Weeks for preterm baby?
viable - 37 weeks
Prenatal Care of?
Initial Visit for mother?
-screening history, physical, labs
-identification of specific "high risk" factors
-no one goes this far anymore
Progressive Monitoring of Pregnant Mother
-Rh, diabetes, anemia, STD, group B strep carrier
-plan for delivery
Nutrition of Pregnant Mom
-weight gain - plus
-obesity is a form of malnutrition
-essential amino acids (9)
Blood pressure with Pregnant Mom
1. Pre-existing: medications-contraindicated ACE inhibitors, 50% congential malformation if organogenesis exposure
2. Hypertension of pregnancy:
-HTN, proteinuria, attributable to being pregnant
-natural history leads to death
-just plain strange syndrome: no good animal models
-one of the major complications of pregnancy
-eclampsia is convulsions
-rhesus (monkey) D antigen
-prior pregnancy event
-mom Rh negative, baby positive, possible sensitize mon, develops antibodies "rejects next pregnancy"
-Solution: coat the fetal red cells which may contain Rh antigens using IgG so mom doesn't "see" antigen
Diabetes in Pregnancy
2. Gestational (45-50% dev overt DM later in life)
3. Diet Controlled
4. Insulin-Dependent (body can't make type 1, insentitive type 2)
5. oral hypoglycemic
6. high risk: prior DM in pregnancy, multiple gestation, AMA, obese
hCG - alpha structure
-similar to TSH
-similar to insulin
-one or more
-survey anatomic structural at 18-20 weeks
1. structure (also where and how many)
2. blood flow
3. amniotic fluid
Fetal Heart Rate Monitoring
-strict criteria 110-160 BPM baseline rate
-heart rate "accelerations"
-heart rate "decelerations"
Family Issues with Pregnancy
-mixing medicinve and sociology
Onset of Labor
3. Rupture of membranes "water breaks"
-regular, phasic contractions sufficient to cause progressive dilation of the cervix
1. Latent Phase - "pre labor" <4cm
2. Active Phase - 1st 4-10cm
3. Pushing - 2nd
4. Delivery placenta 3rd
-ability to live outside the uterus
-fetus is premature, different that preterm
What % of pregnancies are normal?
-not counting repeat C/S
-Complications of pregnancy:
infection, preterm labor, pre-eclampsia, prior C/S, not vertex
Duration of Latent
Duration of Active
-Friedman curve, actually 1-2cm/hr
Duration of 2nd stage
-3 hr primip or 2 hr multip
Duration of 3rd stage
-regular, normal, usual
Delivery of Placenta
-gentle traction: do not avulse cord
-is it intact?
Assess for Damage
-vaginal wall laceration
1st degree-skin only
2nd-defect of underlying tissue but not through anal sphincter (must repair)
3rd-into or through sphincter (repair)
4th-defect of rectum (repair)
Assisted Vaginal Delivery
-vacuum (no only if have to, or if don't want mom to push)
-vaginal bypass operation
-Tocolytic (toco-childbirth cutting, really means stopping preterm birth)
-the C/S rate is too high or too low
-US: low 30% (20% for primigravidas)
-Puerto Rico is 70%
Vaginal Birth after Cesarean Section
-uterine scar: ruptured uterus with subsequent labor
-if many more children are desired, trial of labor
-vaginal birth after C/S
Risk of C/S
1. increased bleeding
2. increased risk of infection
3. increased risk of intraabdominal scarring
4. increased risk of uterine rupture with each additional C/S
5. Increased risk of placenta accreta, next pregnancy
Maternal Mortality: Statistics
-250,000-343,000 deaths worldwide
-99% in economically disadvantaged countries
-nearly linearly associated with illiteracy rate, education, poverty
-morbidity is 20x mortality
-death occurring during pregnancy, or within 6 weeks of delivery, excluding accidents or if the pregnancy is incidental to cause of death
-maternal mortality ratio: # deaths/100,000 live births in one year
Maternal Mortality Rate
# deaths/ # women of reproductive age
How many maternal deaths in US are preventabe?
50% - 27%
Problems that lead to ectopic pregnancy?
1. damage to cilia
2. blind pouch
Why recient rise in mortality?
-increased C/S rates
-High unintended pregnancy
-no pre pregnancy counseling
-domestic abuse rates are high in US
Racial Disparity in Pregnancy
-african american: white 4:1
-education not independent risk factor
-income not independent risk factor
28 to <32 weeks
Moderate to late Preterm
32 to <37 weeks
Cardiovascular Adaptation During Pregnancy
#1-systemic vascular resistance goes down (dec. 20-25% in early pregnancy, reached by 5 weeks)
#2-blood volume goes up 30%, need to supply baby
-bp & heme decrease
What group of cells remodel the spiral arteries?
-cytrtrophoblasts (extravascular trophoblast)
Remodeled Vessels are??
When does remodlin start?
at 4 weeks of pregnancy
-uterine spiral artery containing maternal blood
-maternal endometrium has become decidualized meaning that the stromal cells have been transformed into large pail cells
-infiltrating b/w these decidual cells are trophoblasts
hCG levels level off when?
-at 20 weeks (baby grows by deposition of fat)
What causes total vascular resistance to decrease?
-reduced vasomotor tone and remodelling of resistance-sized arteries (because of remodin & ADAM 12)
Women with preeclampsia have higher and lower what?
Higher: conc. of sVEGRF-1 and sENG
Lower: conc. P1GF
-have imbalance of angiogenic/antioangiogenic factors
Regulation of Cardiac Output during Pregnancy?
-decreased ventricular afterload (1st trimester)
-increase in cardiac output & relative arterial underfilling
Physiologic anemia of pregnancy?
-increase in plasma volume is faster than increase in erythrocyte volume (give iron)
Timing of Plasma Volume change?
-happens in 4-8 weeks
-returns to normal 6 weeks after delivery
What happens if plasma volume doesn't increase enough?
-related to not enough fetal growth
Does the heart change in pregnancy?
-yes, ventricular remodeling
-apical four chamber views showing the normal heart remodelling with eccentric hypertrophy in a normal third trimester pregnant women
-increased myocyte volume without fibrosis, increased heart elasticity to comply with increased volume
-increased injection fraction, stroke volume, cardiac output
Renal Adaptation in Pregnancy
-GFR increases by up to 50% above baseline (b/c elevations in cardiac output & kidney blood flow)
-decrease in serum creatine concentration (0.4mg/dL)-normal levels 0.9 may indicate kidney disease
-hydronephrosis (more on right)
Why do pregnant women have hydronephrosis?
-progesterone-induced ureteral smooth muscle relaxation and ureteral compression secondary to the enlarging fetus results in dilatation of the urinary collecting system
Respiratory System in Pregnancy
-uterus enlarges, diaphragm is elevated (4cm), doesn't impede movement
-rib cage is displaced upward & widens, increasing the lower throacic diameter by 2cm and thoracic circumference by 6cm
-chest circumference expands 5-7cm
-subcostal angle increases from 68-103 deg
-respiratory muscle function is not affected
-abdominal muscles have less tone, less active
In pregnancy, what happens to dead volume?
-increases to relaxation of the musculature of the conducting airways
Pregnancy: Tidal Volume
-increases gradually (35-50%) as pregnancy progresses
Pregnancy: Total Lung Capacity
-reduced (4-5%) by elevation of the diaphragm
Pregnancy: Functional Residual Capacity, Residual Volume, Respiratory Reserve Volume
-dec. by 20%
Pregnancy: Residual Volume, Tidal Volume
Residual Volume smaller & Tidal Volume Larger caused by increased alveolar ventilation (about 65%) during pregnancy
Pregnancy: Inspiratory Capacity
Pregnancy: Alveolar Oxygen Tension
-in normal limits, lowers maternal blood CO2 tension
-considered a protective measure that prevents that fetus from the exposure to excessive levels of CO2
Gas Exchange in Pregnancy
-hyperventilation leads to decreased PCO2
-increases CO2 gradient b/w fetus and mother
-chronic respiratory alkalosis
-compensatory metabolic acidosis
-20-40% increased in maternal oxygen consumption
-normal arterial blood gas values pH-7.4-7.45
PCO2 = 28-32 PO2=101-106 HCO3=18-21
Hormone Changes in Pregnancy
-pregnancy increases estrogen/progesterone
-decrease pituitary growth hormone b/c placental GH takes over
Pregnancy looks hormonally similar to?
How is pregnancy like obesity?
-leptin resistance (need increased fat content for babies brain), made by placents (10x)
-high cortisol level
Does bacteria change in pregnancy?
-yes, causes increased insulin resistance
Pregnancy HPA axis?
-placental CRH stimulates both the maternal pituitary and adrenal, leading to increased cortisol producing
-rising cortisol stimulates placental CRH production
Passage of cortisol through placenta?
-partially inhibited by placental HSD2
-if to much gets to baby, bad effects
What happens if mother has stress or 11beta-HSDw is decreased?
-baby gets more cortisol in its blood
Mechanisms of Materno-Fetal Transfer
1. transported intact
2. partially consumed by placenta
3. metabolized by placenta (cortisol)
4. not transported
What are stem cells of the placenta?
-uptake form maternal blood by endocytosis transport across cytosol via vesicular transport released into fetal circulation via exocytosis (immunoglobulins)
-hydrophobic molecules soluble in plasma membrane (respiratory gases)
-hydorphillic molecules exchanged via water filled channels/pores, driven by electrochemical driving forces (small solutes, sodium, calcium, K)
Protein Mediated Transport
-hydrophillic molecules, mediated via specific proteins in maternal and fetal facing plasma membranes (ions, amino acids, glucose)
What is the primary barrier for transfer of nutrients from mother to fetus?
What type of transports are increased towards the end of pregnancy?