Physiologic/Endocrine Changes during Pregnancy and Parturition

Question 1

ovulation

Answer 1

regularly around day 15

increasing P and E from corpus luteum

Question 2

if fertilization occurs

Answer 2

blastocyst hatches from zona pellucida and inplantation begins day 22-23

release of hCG

Question 3

hCG

Answer 3

rescues corpus luteum

secreted from trophoblast after it attaches to endometrium

Question 4

receptive period

Answer 4

day 20-24 approx

decreased antiadhesion protein and increased adhesion protein uterine endometrium

Question 5

pregnancy duration

Answer 5

determined by date of last menstrual cycle

nornally aound 40 weeks
-38 weeks from ovulation

Question 6

hormone pregnancy test

Answer 6

beta-hCG

can be detected 24 hours after implantation in urine

Question 7

major hormones of pregnancy

Answer 7

hCG
progesterone
estrogens
hPL / hCS

Question 8

estrogens

Answer 8

estradiol
estrone
estriol

Question 9

hPL

Answer 9

human placental lactogen

Question 10

hCG

Answer 10

important first trimester

-rescue corpus luteum

Question 11

luteal placental shift

Answer 11

production of progesterone and estrogen from corpus luteum to placenta

8 weeks

very important
if doesnt occur - no pregnancy

Question 12

2nd and 3rd trimester

Answer 12

progesterone and estrogen levels continue to rise

release by placenta

Question 13

hCG

Answer 13

produced by syncytiotrophoblasts
half-life 30 hours

detected by pregnancy tests

may be responsible for morning system

peaks 10 weeks after implantation

double every 2 days during first 6 weeks

Question 14

hCG structure

Answer 14

similar to LH, FSH, TSH - mostly LH
binds to receptors with high affinity
-maintain corpus luteum

can also bind TSH receptors
-transitional gestational hyperthyroidism

Question 15

transitional gestational hyperthyroidism

Answer 15

hCG weakly binds TSH

Question 16

other hCG actions

Answer 16

stimulates leydig cells > testosterone (mimics LH)

stimulates adrenal cortex

Question 17

progesterone

Answer 17

increases rapidly when production switches to placenta

around 8 weeks

required to maintain a uterus - quiescent myometrium**

cannot be indicator of fetal healthy
-just placental function

Question 18

high levels of progesterone need

Answer 18

CYP11A1, 3-beta hydroxysteroid DH, and maternal cholesterol

Question 19

actions of progesterone

Answer 19

decreased uterus motility/contractions

increased secretions of uterus
-nourishment, growth, implantation of embryo

increased fat deposition early in pregnancy
-appetite, sugar to fat

Question 20

estrogens

Answer 20

placenta takes over production around week 8

Question 21

estrogen synthesis

Answer 21

require products from fetus
-19 carbon androgen (DHEA-S) from adrenal gland

can indicate fetal status

Question 22

estriol

Answer 22

major estrogen of pregnancy

levels used as indicator of fetal health

Question 23

actions of estrogen

Answer 23

initiation parturition
-important end of term

increased blood flow
increased smooth muscle hypertrophy
increased prostaglandins
increased oxytocin
increased mammary gland growth
increased prolactin secretion
increased LDL receptors on syncytiotropoblasts

Question 24

estrogen:progesterone ratio

Answer 24

shifts later in pregnancy

-preparing for parturition

Question 25

after parturition

Answer 25

decreased progesterone - allows for PRL action on breast and lactation

Question 26

hPL

Answer 26

aka hCS produced by syncytiotrophoblasts - detected in maternal serum by 3 weeks - rise throughout pregnancy - proportional to placental growth

Question 27

rises in proportion to placenta growth

Answer 27

hPL (hCS)

Question 28

actions of hPL

Answer 28

increased glucose availability to fetus ** antagonizes insulin action - inhibits maternal glucose uptake - lipolytic - stimulates mammary gland development

Question 29

maternal-placental-fetal unit

Answer 29

distinct but work together fetal health can decline with functioning placenta non-functioning placenta always detrimental to fetus

Question 30

placenta

Answer 30

site of exchange | gas, nutrients, exchange, hormones, antibodies, drugs, viruses

Question 31

function of placenta

Answer 31

maintain pregnant state of uterus (progesterone) stimulate lobuloaveolar growth of breasts support fetal growth regulate fetal development regulate timing of parturition

Question 32

P and E normal cycle vs. pregnancy

Answer 32

much much higher levels in pregnancy because placenta can produce so much

Question 33

limitations of placental

Answer 33

cannot make cholesterol | lacks enzymes for estrone and estradiol, estriol production

Question 34

contribution of mother

Answer 34

LDL cholesterol

Question 35

fetus contribution

Answer 35

3 main enzymes to produce estrogens 17 alpha hydroxylase 17,20 desmolase 16 alpha hydroxylase

Question 36

DHEA-S

Answer 36

produced in fetus -first product of the 3 enzymes of estrogens -goes back to placenta where its converted to estrogens

Question 37

prolactin

Answer 37

estrogens increases PRL release from anterior pituitary lactotrophs hypertrophy and hyperplasia -can increase pituitary size

Question 38

increased pituitary size

Answer 38

can cause dizziness and vision problems -optic chiasm can be susceptible to insult and necrosis -sheehans syndrome

Question 39

sheehans syndrome

Answer 39

vascular insult and necrosis due to increased pituitary size during pregnancy

Question 40

decreased LH and FSH

Answer 40

negative feedback on estrogens and progesterone

Question 41

ADH secretion augmentation

Answer 41

lower set point for release -released at lower osmolarity threshold altered by progesterone action

Question 42

thyroid size

Answer 42

increased - stimulated by hCG - weakly binds TSH receptors increased total T4 and total T3** estrogen promotes increased liver production of thyroxine-binding globulin no change in free T4 and T3**

Question 43

cortisol levels

Answer 43

increase total cortisol -estrogen stimulate increased liver production of cortisol-binding protein increased free cortisol - later in pregnancy - increased 2x by parturition

Question 44

cortisol inactivation

Answer 44

to protect fetus | by placental 11-beta DH type II

Question 45

aldosterone levels

Answer 45

increases dramatically estrogen stimulates angiotensinogen and renal renin production -ANG II and aldosterone increase progesterone blunts aldosterone action doesnt cause hypernatremia, hypokalemia, HTN

Question 46

woman with normal BMI

Answer 46

25-35 lb increase with pregnancy 30 lbs, 10 lbs fat, 1.5 lb uterus, 4.5 lb breasts, 1.5 lb placenta, 2.2 lb amniotic fluid, 2 lb maternal blood, 7 lbs fetus

Question 47

cardiovascular changes during pregnancy

Answer 47

increased blood volume increased CO decreased TPR ``` decreased MAP (or remains same ) -balance between CO and TPR ```

Question 48

MAP = ?

Answer 48

CO x TPR

Question 49

hematocrit

Answer 49

increased during pregnancy

Question 50

increased blood volume

Answer 50

increased 45% near end of pregnancy adequate fetal perfusion and exchange protects mother blood loss during delivery

Question 51

cause of increased blood volume

Answer 51

increased plasma volume - increased NaCl retention - stimulated by estrogen increased water retention and intake - lower threshold for ADH/AVP and thirst during pregnancy - increased sensitivity to osmoreceptors

Question 52

hematocrit changes

Answer 52

decreased -physiological anemia RBC production can't keep up with plasma increase decreased viscosity, decreased TPR -helps minimize maternal cardiac work

Question 53

hematocrit effect

Answer 53

decreased viscosity of blood