Partuition

Question 1

Four phases cervix goes through in pregnancy

Answer 1

Softening occurs during the majority of pregnancy,

Ripening occurs 1-2 weeks before labor,
Dilation occurs during labor
Postpartum repair occurs after delivery.

Question 2

Cervical dilation is likely a result of t

Answer 2

he mechanical force from contractions and fetal head descent, and changes in cervical composition leading to increased compliance.

Question 3

In early pregnancy, uterine growth is secondary to _________; myometrial cell hypertrophy leads to uterine growth from mid gestation onward. Uterine fibrous and connective tissue, blood vessels and lymphatics also increase during pregnancy.

Answer 3

myometrial cell proliferation

Question 4

Myometrial cells proliferate in early pregnancy

• Myometrial cells hypertrophy in____ half of pregnancy
• ______between myometrial cells increase during pregnancy
• Major increase in the blood supply to the uterus

Answer 4

later

Gap junctions

*17% gravid and 2% non-preggers

Question 5

• Myometrium is comprised of smooth muscle: Contractility is dependent on

Answer 5

spontaneous action potentials increasing intracellular calcium leading to activation of ATPase through a phosphorylation pathway.

Question 6

Myometrial cells contract in synchrony during labor leading to frequent, forceful, and longer contractions. Synchrony is achieved by

Answer 6

the passage of currents through gap junctions made of proteins called connexons. These increase in size and abundance during pregnancy.

Question 7

Myometrial Cells can spontaneously contract

Answer 7

• Spontaneous action potential
• No hormonal input is needed
• No nervous input is needed

Question 8

How are uterie contractions generated?

Answer 8

• Myometrial action potential–> Increase in intracellular

calcium–> Calcium binds calmodulin–>Myosin light chain kinase

activated–> Myosin is phosphorylated –>ATP is hydrolyzed

Myosin undergoes structural change–> Myosin forms a crossbridge with actin leading to contraction

Question 9

Transition from the quiescence phase to labor phase involves a shift from_____ dominance to____ dominance

Answer 9

progesterone –> estrogen

Question 10

Inhibits intracellular Ca entry

Inhibits release from sarcoplasmic reticulum

Membrane hyperpolarization via potassium channels

Inhibits expression of CAP genes

Levels are constant before and during labor, tissue level may vary

Answer 10

Progesterone

Question 11

Increases gap junctions btwn myometrial cells allowing for contraction synchrony between cells

Increases oxytocin receptor and prostaglandin receptor expression in myometrium.

Answer 11

Estrogen

Question 12

• Initiate excitation
• Increase frequency and amplitude of contractions

see more of these going into labor

Answer 12

• Uterine stretch and Estrogen upregulate contraction-associated proteins (CAP) in the myometrium

Question 13

Gap Junction protein connexin-43

Oxytocin receptor

Corticotropin-releasing hormone receptor

Cyclo-oxygenase (COX)-2 enzyme

Answer 13

all upregulated in labor

Question 14

What type of contraction do we see during labor

Answer 14

G protein coupled receptor –> Activates phospholipase C –>Stimulates release of calcium from intracellular stores–> Myosin light chain kinase activation

Question 15

_____synthesized by hypothalamus, stored in the posterior pituitary, increases prostaglandin and estrogen level

Answer 15

Oxytocin

Question 16

Possible triggers for labor

Answer 16

• Fetal adrenal gland plays an important role
• Contributes to the idea of fetal signal
• Increased maternal estrogens
• Increased prostaglandins
• Increase in CAP

Question 17

Once the baby has fnx adrenal gland, increases production of ______ that can get converted into estriol to upregulate CAPS as the fetal/maternal membrane

Answer 17

baby makes DHEAS

Question 18

The baby can make _____ which will increase placental oxytocin, prostaglandinsand placental CRH during induciton of labor which goes to mom to further stimulate labor

Answer 18

cortisol

Question 19

Latent phase: contraction with slow cervical dilation

Active phase: contractions with fast cervical dilation

Answer 19

First stage of labor

Question 20

Complete dilation until delivery of fetus

Post delivery of fetus to delivery of placenta

Answer 20

SEcond phase

Third phase

Question 21

Lasts one hour after delivery of placenta Constant myometrial contraction that limits blood loss

Answer 21

Fourth stage

Question 22

delivery between 20 weeks gestation and 37 weeks gestation

• Contraction mechanism is the same
• What leads to the contractions is likely different

leading cause of infant mortality and long term neurological disabilities

Answer 22

Preterm Labor

Question 23

4 factors involved in preterm labor

Answer 23

Uterine distension

Maternal fetal stress

Premature rupture of membranes

infection

Question 24

How can infetion lead to premature labor?

Answer 24

• Toxins produced by bacteria stimulate to cytokine production leading to prostaglandin release

Question 25

How does uterine distension lead to preterm labor?

Answer 25

* CAP expression * CRH and Estrogen increase * Oxytocin release * Uterine activation

Question 26

How does maternal-fetal stress lead to premature labor

Answer 26

• Premature rise in cortisol and estrogens can induce labor phenotype and stimulate fetal adrenal c19 hormones

Question 27

Identifiable preterm labor risk factors

Answer 27

infection, periodontal disease, smoking, genetics, cervical shortening, decreased uterine space, low pregnancy weight

Question 28

Used to Tx preterm labor

Answer 28

magnesium, Ca+ channel blockers, Prostaglandin synthesis inhibitors, B-2 adrenertic receptor agonist (via inhibiting intracell Ca+ influx)

Question 29

is used to prevent preterm delivery in patients with a history of preterm delivery and for patients with a shortened cervical length by ultrasoun

Answer 29

Progesterone therapy

Question 30

is best defined as bleeding leading to symptoms of hypovolemia \> 500 mL blood loss after a vaginal delivery \>1000 mL blood loss after a cesarean delivery

Answer 30

Post partum hemorrhage \*• Hemorrhage is the leading cause of maternal mortality

Question 31

Whe do we see post partum hemorrhage?

Answer 31

occurs during 3rd stage of labor during delivery of placenta

Question 32

uterine relaxation during the 4th stage leading to **excessive blood loss** * Treated with uterine massage * Pharmacologic treatment with **oxytocin, prostaglandins, ergot alkaloid **

Answer 32

• Atony

Question 33

Risk for atony

Answer 33

Precipitous Labor, Large Fetal Weight , Multifetal Gestation, Polyhydramnios, Prolonged Labor, Retained Placenta, Grand Multiparity, Intrauterine Infection, Uterine Relaxation Agents

Question 34

* Hypovolemia from obstetrical blood loss leads to pituitary infarction or necrosis * Symptoms may not develop immediately : lactation failure, hypoglycemia, and life threatening hypotension from adrenal insufficiency. * Symptoms are varied secondary to the many end organ targets of pituitary hormones

Answer 34

Sheehan Syndrome

Question 35

Pt not contracting after delivery and starting to see lots of blood loss, what may help stimulate contractions and prevent lss of blood?

Answer 35

prostaglandins