Endocrinology of Pregnancy and Placenta

Question 1

Increase or decrease in pregnancy?
Calcium (total)
Calcium (ionized)
Calcitonin
Phosphate
PTH (in the first trimester)
PTH (in the second and third trimesters)
PTH-rP
Vitamin D

Answer 1

• Decrease: Ca, PTH (1st trimester), Phosphate
• Increase: active vitD, PTHrP, PTH 2-3rd trimester, calcitonin (slight)
• No change: ionized Ca, magnesium

PTH overall goes down but made up for by PTHrP made by fetus

Question 2

Deoxycorticosterone change during pregnancy

Answer 2

Increases due to kidney production

Question 3

DHEA-S change during pregnancy?

Answer 3

Decreases due to (1) 16-alpha-OHase in mom liver and (2) steroid sulfatase in placenta aromatizing to estriol

Question 4

Androstenedione change during pregnancy?

Answer 4

Total goes up due to more SHBG

Question 5

Testosterone change during pregnancy?

Answer 5

Total goes up due to more SHBG

Question 6

GnRH change during pregnancy?

Answer 6

Decreased response to it

Question 7

Explain CRH / ACTH / cortisol changes during pregnancy

Answer 7

ACTH initially downregulated but then placenta produces some CRH so ACTH goes up. This + cortisol clearance rate slowing so serum level increases.

Question 8

GH change during pregnancy?

Answer 8

Decrease in pituitary; increase in placental GH

Question 9

The increase in which hormones promote lactation?

Answer 9

Insulin, cortisol, PRL

Question 10

What metabolizes steroids in placenta?

Answer 10

11-beta-HSD-2 and CYP1A1

Question 11

What increases and decreases decidual production of PRL (which enters AF)?

Answer 11

Increases: arachadonic acid.
Decreases: cytokines, growth factors (EGF, ET-1, IL-1, IL-2)
No effect: prostaglandins and dopamine stuff or TRH

Question 12

Which placenta cell makes hPL

Answer 12

SCT

Question 13

Which hormones is hPL similar to?

Answer 13

Pituitary GH (96%) and PRL (67%)

Question 14

Which placenta cell makes all the steroid hormoens

Answer 14

SCT

Question 15

Which placenta cell makes GnRH

Answer 15

Cytotrophoblasts

Question 16

Which placenta cell makes leptin?

Answer 16

SCT and CT (though adipose makes more)

Question 17

Describe path through a hemochorial placenta

Answer 17

Mom blood (capillary) -> intervillous space bathing -> SKIN-cytiotrophoblast -> cytotrophoblast -> fetal mesenchyme aka connective tissue -> fetal capillary endothelium -> fetal capillaries

Question 18

How does this cross placenta? CO2

Answer 18

Passive diffusion

Question 19

How does this cross placenta? Oxygen

Answer 19

Passive diffusion

Question 20

How does this cross placenta? FFA

Answer 20

Passive diffusion

Question 21

How does this cross placenta? Glucose

Answer 21

Little bit of facilitated diffusion, little bit active GLUT-1

Question 22

How does this cross placenta? Lactate

Answer 22

Facilitated diffusion

Question 23

How does this cross placenta? Amino acids

Answer 23

Active transport via SCT

Question 24

How does this cross placenta? Calcium

Answer 24

Active transport via SCT

Question 25

How does this cross placenta? Iron

Answer 25

Active transport via SCT

Question 26

How does this cross placenta? Iodine

Answer 26

Active transport via SCT

Question 27

How does this cross placenta? Vitamin C

Answer 27

Active transport via SCT

Question 28

How does this cross placenta? IgG

Answer 28

Pinocytosis

Question 29

How does this cross placenta? Insulin

Answer 29

Pinocytosis

Question 30

How does this cross placenta? LDL

Answer 30

Pinocytosis

Question 31

How does this cross placenta? Transferrin

Answer 31

Pinocytosis

Question 32

How do most drugs cross the placenta?

Answer 32

Passive diffusion

Question 33

Which cells don't express MHC Class I or II Ag?

Answer 33

SCT

Question 34

Which cells don't express MHC Class II Ag but have Class I?

Answer 34

EVT

Question 35

What four enzymes does placenta have the are critical to making estrogen?

Answer 35

1. 3-beta-HSD 2. 17-beta-hydroxylase 3. Steroid sulfatase 4. Aromatase

Question 36

What enzyme does placenta have to make sex hormones that fetal adrenal lacks?

Answer 36

3-beta-HSD

Question 37

What estrogen version is in blood and circulating at term? What version has low SHBG affinity so is mostly cleared in the urine (and lots in urine)?

Answer 37

EstraDIol and EsTRIol

Question 38

Two ways to get 46 XX ambiguous genitalia

Answer 38

1. Excess androgen (either tumor or exogenous) | 2. CAH (21-OH most common > 17-OHase > 3-beta-HSD)

Question 39

Why give fetus at risk for 21-OH CAH dexa @ 4 wks?

Answer 39

Prevent virilization (i.e. only give it to female fetus).

Question 40

Ambiguous genitalia (in utero) work-up?

Answer 40

Karyotype + 7-DHS (for SLO evaluation)

Question 41

Name 3 things 11-Beta-HSD-2 inactivates

Answer 41

Cortisol -> cortisone Corticosteroid -> 11-deoxycorticosterone Prednisolone -> Prednisone

Question 42

How does PGF-2-alpha trigger a contraction?

Answer 42

Two ways: Increase CA via ATPase and release from sarcoplasmic reticulum

Question 43

How does PGE1 trigger a contraction?

Answer 43

Two way: Increases Ca and INHIBITS adenyl cyclase

Question 44

How does a decrease in Ca relax a uterus?

Answer 44

Myosin PHOSphatase takes that PO4 off and de-couple

Question 45

How do beta-2-adrenergic (like terbutaline) relax a uterus?

Answer 45

B2 activate adenyl cyclase turning ATP into cAMP which then activate PROTEIN KINASE A which then (1) deactivate MLCK by phosphorylation, (2) stop Ca influx (3) stop Ca-calmodulin binding

Question 46

``` Which of these increase vs decrease contractions? ANP Calcium Calcitonin cAMP cGMP Cortisol CRH endothelin EGF Estrogen Growth Factor hCG Mg NO Progesteorne PTHRP Relaxin Prostacyclin ```

Answer 46

* Increase ctxn: PGF > PGE, ADH, endothelin, epidermal GF, estrogen, cortisol, Ca (mnemonic: all the Es [endothelin, estrogen, epidermal GF] + stress] * Decrease ctxn: cAMP, cGMP, hCG, relaxin, prostacyclin, NO, ANP, progesterone, calcitonin, Mg * CRH and PTHrP do both

Question 47

How do IL1-beta + TNF-alpha increase contractions?

Answer 47

Increase prostaglandins by (1) inducing COX-1 expression in amnion/decidua and (2) inhibiting PGDH in chorion

Question 48

Where does PGE2, PGF2 alpha, and PGI2 come from?

Answer 48

* Amnion: PGE2 * Chorion: PGE2 (…and a little PGF2-alpha but most inactivated) * Decidua vera: PGF2-alpha (primary source in the uterus) >> PGE2 * Myometrium: PGI2 * Placenta/cord: PGE2>PGI2