190b Normal Preg

Question 1

uterus - effect of estrogen? progesterone? blood flow during pregnancy?

Answer 1

estrogen mediated hypertrophy –> 5-20 L
-placenta makes estrogen from fetus which enter maternal circulation

progesterone–> thick cervical mucus + relaxation of smooth muscle, ligaments

progressive increase in uteroplacental blood flow during progression

Question 2

chadwick sign

Answer 2

bluing of vagina and cervix

hypertrophy and hyperplasia of cervical glands –> eversion

increase mucosal thickness and loosening of CT in vagina

Question 3

CV changes in preg

Answer 3

elevation of diaphragm –> enlarged silhouette

1. 5 blood volume and CO
2. 15 resting hr

Question 4

BP during preg

Answer 4

1st trimester - similar to non-preg

increases progesterone - reduces systemic vascular resistance –> lowest in 2nd trimester

increases back to normal in 3rd trimester (due to blockage of IVC)

PVR, osmotic P (edema), SVR all decrease

Question 5

respiratory changes in preg

Answer 5

elevation in diaphragm–> subcostal angle increases

decreases RV and FRC

increase in TV –> same rr –> respiratory alkalosis (lowers PCO2) but bicarb is lost for compensation

Question 6

GI and preg

Answer 6

high B-hCG –> nausea/vomiting in 1st trimester

increased smooth muscle relax due to P –> GERD, constipation, decreased gallbladder motility

same gastric emptying time though

increased hepatic blood flow and changes hepatic labs (hypercoagulable state)

Question 7

renal and preg

Answer 7

1.5 GFR and RPF (must titrate drugs - Thyroid hormone) –> lower serum Cr

ureters displaced by uterus –> hydronephrosis

Question 8

blood and preg

Answer 8

increased plasma volume and rbc’s –> still hemodiluted though –> able to tolerate 1000 cc during birth

higher iron –> goes to fetus

slight leukocytosis (low wbc count) - more CD8 and granulocytes; less CD4 and PMNs

Question 9

what causes increased circulating hormones in preg?

Answer 9

fetus and placenta –> E and P

increase T4/3 total, but free levels the same –> higher TBG due to increased estrogen

stable TSH/TRH

Question 10

metabolic rate

Answer 10

increased 10-20% in preg

weight gain 25-35 lbs if not fat

max need another 300kcal/day

hyperplasia of b cells –> increased insulin –> fasting hypoglycemia and post meal hyperglycemia

lipids increased in preg –> need hormone biosyn

Question 11

placenta physiology

Answer 11

spiral arteries bath intervillous spaces with maternal blood

Question 12

fetal physiology

Answer 12

one umbilical vein
2 umbilical arteries

normal shunts x 3
ductus venosus
foramen ovale
ductus arteriosus

high pulmonary vascular resistance

Question 13

circulation changes at birth

Answer 13

fetal breathing at 16-22 weeks –> draws amniotic fluid into lungs; need intact amniotic fluid

canalicular stage at 16-25 weeks - when adverse events happen; fetal viability issues b/c lungs don’t work until 24 weeks

continues to develop up to 8 years

alveolar expansion –> increases O2–> reduces pulm vascular resistance –> decreases RA/RV P –> closes forame ovale

backflow of o2 blood in ductus arteriosus –> vasoconstriction

Question 14

fetal hb

Answer 14

2 a and 2 gama chains

made in liver mostly

shifts o2 curve elft – increased affinity

Question 15

fetal GI and renal

Answer 15

swallowing at 10 weeks

kidneys urine at 16 weeks – amniotic fluid

Question 16

endcrine

Answer 16

maternal thyroid until 10-12 weeks

fetal adrenals are huge due to large fetal zone

Question 17

tetralogy of fallot risk factors

Answer 17

DM with poor control

down syndrome

22q11 deletions - DiGeorge mutation

must maintain ductal patency – need prostaglandins at birth

Question 18

labor

Answer 18

smooth muscle contraction

power - strength and freq (3-5/10 minutes); can change with medical management

passenger - fetus size vs pelvis, attitude

passage - maternal bony pelvis

can only affect power with medicine

Question 19

stages of labor

Answer 19

1 - between onset of contractions and full cervical dilation

latent phase - no dilation; active - rapid dilation

2 - between full dilation and delivery of fetus

3- between fetus and placenta