Week 3- Normal Pregnancy and Delivery

Question 1

What is “hemochorial”, “decidua” and “decidual” reaction?

Answer 1

“hemochorial”= maternal blood coming in direct contact with chorion. OR “the human trophoblast invades the maternal epithelium”

“decidua”= modified uterine lining during pregnancy

“decidual reaction”= thickening of decidua to prevent invasion of trophoblast beyond epithelium

Question 2

When is the uterus most receptive to implantation?

Answer 2

• 6-7 days post fertilization or 8-10 days after the LH surge

Question 3

What are the three kinds of cytotrophoblasts?

Answer 3

villus–> make the primary villi

extravillus–> do spiral artery remodelling (goes down 1/3 into myometrium, but just around the spiral arteries)

endovascular

Question 4

What are the kinds of deep placental invasion?

Answer 4

• Placenta accreta
• Placenta increta
• Placenta percreta

Question 5

What is the highest risk of placenta accreta?

Answer 5

2 prior c-sections with current placenta previa (40% risk of accreta…25% with single c-section + previa)

Question 6

How does glucose, oxygen, amino acids, IgG get across the placenta?

Answer 6

Glucose: faciliated (not insulin dependent)..N.B: glucose is not produced by the placenta until labor

Oxygen

Amino acids: active transport (fetus is an area of “high amino acid concentration”

IgG: endocytosis

Question 7

What cells produce hCG? How often does it double?

Answer 7

Syncitiotrophoblasts, it double q48hrs and peaks at 10 wks

Question 8

What is hPL and where does it come from?

Answer 8

human placental lactogen: syncytiotrophoblasts. It supports the metabolic needs of the placenta including being anti-insulin (–> GDM)

Question 9

How long does the corpus luteum produce progesterone for?

Answer 9

Until 10 wks, then it switches to the placenta

Question 10

How is estrogen produced by the placenta and what does it do? How is corticosteroid produced?

Answer 10

from maternal and fetal androgens. increases blood flow, cardiac output and vasodilates.

corticosteroid: from placental progesterone- important for lung maturation!!!!!!!!!!!!!!!

Question 11

How and where is amniotic produced in the first trimester and in the 2/3 trimester?

Answer 11

• 1st trimester: fetal surface of placenta and fetal skin secretions
• 2/3 trimester: fetal urine and fetal lung liquid

Question 12

Factors influencing fetal oxygenation?

Answer 12

1. Maternal oxygenation
2. Uterine blood flow
3. PLacental 02 transfer
4. Umbilical cord blood flow
5. Fetal 02 capacity

Question 13

How does the fetus clear acid?

Answer 13

• H2CO3 diffuses rapidly across the placenta

Question 14

Does anaerobic metabolism normally happen in the fetus?

Answer 14

No, only if fetal oxygenation is impaired. They take hours to clear the placenta.

Question 15

What does a metabolic vs. a respiratory acidosis look like on cord gases? What is base excess?

Answer 15

Both: have low pH

Resp: has an increased pCO2 but a normal HCO3-

Met: has a normal pCO2 but a depleted HCO3- from prolonged exposure to acid

Base excess reflects the amount of acid produced by the fetus. A more negative number is bad and reflects metabolic acidosis

Question 16

What is a uterotropin vs. a uterotonin?

Answer 16

Uterotropins set the stage for contractions and cervical changes (e.g. EE, relaxin, PGs)

Uterotonins directly involve contraction (they tone) the uterus (oxytocin, PGF2, endothelin

Question 17

What hormones/compounds aid in cervical ripening?

Answer 17

estradiol

PGE2 (these levels are highest in the forewaters)

decrease in progesterone

relaxin (made in the ovaries)

Question 18

What does PGE2 do and what does PGF2 do?

Answer 18

PGE2: cervical ripening…it is a uterotropin

PGF2: contractions (increases intracellular calcium), it is a uterotonin

Question 19

What medications can you give to prevent preterm labor?

Answer 19

NSAIDs

CCBs

Progesterone

Question 20

How many phases and stages of partruition are there?

Answer 20

• Phase 0: uterine quiescence
• Phase 1: Uterine preparedness
• Phase 2: Active Labor
  
  • Stage 1:
    
    • latent phase: variable length, but contractions are regular and painful and cervix <3 cm
    • active phase: 3–> 10 cm, 1.2 cm/hr for multip and 1 cm/hr for nullip
  • Stage 2: full dilation–> delivery of fetus
  • Stage 3: delivery of fetus–> delivery of the placenta (~30 min…active management)
  • Stage 4: delivery of placenta–> maternal stabilization
• Phase 3 (=puerperium): uterine involution fertility restored

Question 21

What are the cardinal movements (in general)?

Answer 21

Movements the fetus goes through to minimize it’s diameter as it moves down the birth canal

Question 22

Are myometrial oxytocin receptors present in the first trimester?

Answer 22

no

Question 23

Fetal cardiac activity can be seen on US at…

Answer 23

wks

Question 24

Changes in the urinary system in pregnant women include ALL of the following EXCEPT:

There is a marked increase in the glomerular filtration rate.

Glycosuria is common because the tubular reabsorption capacity is exceeded.

Serum concentrations of uric acid and creatinine are higher as a result of the presence of the fetus.

Vascular reactivity to angiotensin II is reduced in pregnancy.

There is dilatation of the ureters and renal pelvis.

Answer 24

There is a marked increase in the glomerular filtration rate.

Glycosuria is common because the tubular reabsorption capacity is exceeded.

Serum concentrations of uric acid and creatinine are higher as a result of the presence of the fetus. (it is reduced because GFR is higher)

Vascular reactivity to angiotensin II is reduced in pregnancy.

There is dilatation of the ureters and renal pelvis.

Question 25

When is the GDM screen done? GBS? TSH?

Answer 25

GDM: ~24 wks

GBS: ~36 wks

Thyroid is not a routine screen

Question 26

On the first prenatal visit, would you do a pap smear?

Answer 26

yes, if her last pap was >6 months ago

Question 27

“The human maternal uterine vein and the fetal umbilical vein have similar PO2.” represents….

Answer 27

the concurrent circulation model

Question 28

Blood flow increased with gestational age to which organs?

Answer 28

skin

kidney

heart

uterus

breast

NOT liver