Pregnancy and Labor-Spielvogel Flashcards
Growth and maturation of the fetus likely controls the majority of events of (Blank)
partuition
The adrenal gland is the place of primary (blank) production. What does the outer definitive zone produce?
What makes up the majority of the adrenal gland at term?
What does the inner fetal zone produce? When does the inner fetal zone involutes?
- hormone
- glucocorticoids
- The inner fetal zone is 80% of the gland at term and primarily androgens
- androgens
- involutes by end of 1st year of life
What does the placenta produce? What does the placenta lack? Why is this important? So how does the baby get estrogen?
steroid and peptide hormones
- 17 alpha hydroxylase
- cannot directly convert progesterones to estrogens
- uses fetal androgens from the fetal adrenal gland as precursor to estrogen
Ovaries produce (blank) in support until (blank) weeks of gestation because the (blank) will take over.
progesterone
7+
placenta
HCG is secreted by (blank) of the placenta. The alpha HCG unit is shared with the (blank) and (blank) hormones while beta HCG is used to test level of HCG.
Trophoblasts
LH and FSH
What is the rule of 10s related to HCG levels?
HCG levels:
roughly 100 when a women misses her period, 100,000 at ten weeks, 10,000 at term
In ectopic pregnancies, β-HCG levels usually increase (blank). Mean serum β-HCG levels are (blank) in ectopic pregnancies than in healthy pregnancies.
less
lower
Early on the fetus lacks enzymes to produce (Blank). As gestational age increases, it begins to secrete it which will stimulate (Blank) release from the placenta. Which stimulates back fetal (blank). This loop is a KEY In the activation of (Blank) both term and preterm.
cortisol
CRH
ACTH
labor
Elevated (blank) is associated with increased risk of preterm labor
CRH
What happens to progesterone levels during pregnancy?
steadily increase
What does progesterone do in the fetus and uterus?
inhibits uterine contractions, gap junction formations,
i.e causes uterine quiessence
Progesterone does the opposite of (blank X 3)
estrogen, cytokines, prostaglandins
What are braxton hix contractions?
when muscle fibers in the uterus contract but not uniformly
(blank) is the most abundant in human pregnancy. How do you make this?
Estriol
from DHEAS in the liver and placenta and with placental enzyme sulfatase
(blank) originates in the definitive or adult zone of the fetal adrena gland
Cortisol
(blank) promotes the differentiation of type 2 alveolar cells and the production of surfactant release into the alveoli
Cortisol
How does cortisol cause labor activation?
increases release of CRH and prostaglandins
What is used to decrease surface tension and allow babies to oxygenate?
surfactant
Where does oxytocin originate?
What stimulates its release?
supraoptic and paraventricular nuclei of hypothalamus and is released by post pituitary.
-mammary stimulation and uterine distension
(blank) from the ovaries induces oxytocin receptors on uterus. (blank) from fetus and mothers posterior pituitary leads to stimulation of uterus contraction and stimulates placenta to make (bank) which stimulates more vigorous uterine contractions.
estrogen
oxytocin
prostaglandins
What is this:
a hormone secreted by the placenta that causes the cervix to dilate and prepares the uterus for the action of oxytocin during labor
Relaxin
In ovarian hyperstim what happens?
excessive relaxin production resulting in increased cervical shortening and risk of preterm labor and women become hyponatremic and results in fluid in the pelvis
prostaglandins are synthesized at or near their point of (blank). WHere are they synthesized?
target
-in endometrium, myometrium, fetal membranes, decidua and placenta
What do prostaglandins do? Prostaglandins work locally/distally?
conraction of the uterus
and contraction of SM In intestine
locally
How do prostaglandins levels fluctuate during pregnancy? How are the levels in spontaneous labor?
In levels seen in women requiring induction of labor?
Rise during pregnancy
Increase further in spontaneous labor
Lower levels seen in women requiring induction of labor
What is considered a term pregnancy?
Early term?
40-41.5
37-39
What plays a major role in initation and control of labor? What forms these?
Prostaglandins
arachadonic acid
Labor appears to be a cascade of events in chorion, amnion, and decidua that converts AA into prostaglandins. (blank) stimulates the enzymes that convert AA to prostaglandins
Estrogen
(blank) levels NOT inducible and remain in low levels in fetal membranes
(blank) MRNA increases during gestation
Cox-1
Cox-2
What does phospholipase A2 do?
frees arachdonic acid from trophoblastic membranes so that you can get prostaglandins
Infection can increase the activity of (Blank) leading to increase prostaglandins and preterm labor. SOO what should you do?
infections
treat the underlying infection :)
Name that prostaglandin!!!!
(blank) is the most potent for ripening cervix.
(blank) alpha has more activity on the uterus
PGE2
PFG2
What hormones promote gap junctions?
What hormones inhibit gap junctions?
estrogen and prostaglandins
progesterone
What are the 4 stages of labor from a hormonal perspective?
Quiescence
Activation
Stimulation
Involution
(blank) plays a major role in quiescence
progesterone
Can you get braxton hix contractions with progesterone?
yes but not labor because progesterone inhibits uniform contraction
How do you get activation of pregnancy?
- uterine stretch
- HPA axis stimulates CRH to ACTH to cortisol and andorgen by fetal adrenal gland
Fetal lungs secrete (blank) a surfactant protein that triggers labor.
SP-A (makes sense since lungs develop last)
What phase of labor is this:
Cascade of events leading to common pathway of uterine contractions, cervical ripening and decidual/membrane activation.
Stimulation
What are the hormone levels during the first trimester?
increased HCG (dominates) increased Progesterone (high levels) Estrogene (lower then progesterone)
What are the hormone levels during the second trimester?
decreasing HCG levels
Increasing progesterone (greater than estrogen)
Increasing estrogen levels
What are the hormone levels during the third trimester?
decreased HCG
increased estrogen and increased progesterone (but progesterone isnt functionally high because estrogen steals its receptors)
SO during the third trimester, functional progesterone withdrawal leads to (blank) which results in increasing gap junctions, oxytocin receptors, prostaglandin production and receptors.
estrogen dominance
What is involution?
Placenta delivered
Surge in Oxytocin
KEY to preventing PPH (post partum hemorrhage)
What does a tocometer tell you?
amount of contractions
What does a fetal fibronectin test tell you?
potential to deliver within the next few days
What is this:
severe abdominal pain, non reassuring fetal heart rate pattern, vaginal bleeding
abruption
Is tocolytic treatment effective or preterm labor?
it is only effective if a 48 hour delay is all you need cuz thats alll it does
Why would you want a 48 hour delay i.e use tocolytic therapy?
- to prolong gestation
- give time to administer betamethasone
- transport to higher care facility
- treat the pyelo, other illness triggering the event
What are contraindications to tocolytic therapy?
- intrauterine fetal demise
- lethal fetal anomaly
- severe preeclampsia or eclampsia
- maternal hemorrhage with hemodynamic instability
- intraamniotic infection
- materna contraindications to the tocolytic therapy
What does COX do? What does cox 2 do?
converts arachidonic acid to PGs
-cox 2 is inducible, dramatically increasing in the decidu and myometrium during term and preterm labor.
What is a cox 1 and 2 inhibitor that prevents preterm labor? Why arent Cox 2 selective inhibitors used anymore?
indomethacin
too many cardiac effects
What are the side effects of indomethacin?
Maternal side effects, -include nausea, esophageal reflux, gastritis, and emesis,
- Platelet dysfunction may occur.
- cardiovascular physiology is minimal.
The primary fetal concerns with use of indomethacin and other COX inhibitors (eg, sulindac, nimesulide) are constriction of the (blank and bank) Possible adverse neonatal effects are also a concern, but data are conflicting.
ductus arteriosus and oligohydramnios.
When does ductal constriction occur due to indomethacin? Therefore when should you prescribe this?
31-32 weeks
Before 32 weeks
What is this:
Maternal administration of indomethacin and other COX inhibitors cause a reduction in fetal urine output, and in turn amniotic fluid volume, because these drugs enhance the action of (blank) and reduce renal blood flow
Oligohydramnios
vasopressin
What are the contraindications for indamethacin?
Maternal: platelet dysfunction or bleeding disorder, hepatic dysfunction, GI ulcerative disease, renal dysfunction and asthma
What do calcium channel blockers (nifedipine) do?
it is a tocolytic-> decreases calcium and leads to myometrial relaxation
What drugs are better, calcium channel blockers (Nifedipine) or indamethacin?
CCBs (nifedipine) because they are ultrasafe
What are the maternal side effects of CCBs (nifedipine)?
nausea, flushing, headache, dizziness, palpitations, increased CO
SEVERE HYPOTENSION in rare cases
What are the fetal adverse effects to CCBs (nifedipine)?
unsubstantiated decreased uterine blood flow and fetal oxygen saturation
What are the contraindications of CCBs?
drug hypersensitivity, hypotension, preload dependent cardiac lesions, LV dysfunction or CHF, people taking magnesium sulfate
Why shouldnt you give magnesium sulfate wth CCBs?
respiratory depression due to suppression of muscular contractility
What are the 2 beta adrenergic agonists? Which one is the only FDA approved drug for preterm labor?
- terbutaline
- ritoderine (this one!)
What are the SEs of terbutaline (beta 2 agonist)?
TACHYCARDIA palpitations lower blood pressure PE (rare) Hypokalemia hyperglycemia lipolysis
What are the fetal side effects of terbutaline (beta agonist)?
- cross placenta and cause fetal tachycardia
- neonatal hypoglycemia may result due to fetal hyperinsulinemia in response to prolonged maternal hyperglycemia
What are the contraindications of terbutaline?
-tachycardia sensitive cardiac disease (due to potent chronotropic effects)
-poorly controlled hyperthyroidism
-DM
-
The FDA has warned that injectable terbutaline should not be used in pregnant women for prevention or prolonged treatment (beyond 48 to 72 hours) of preterm labor in either the hospital or outpatient setting because of the potential for serious (blank)
maternal heart problems
What is the definition of labor?
uterine contractions with cervical change
(blank) is the most commonly used beta-adrenergic receptor agonist for labor inhibition
terbutaline
Is terbutaline for long term or short term tx?
short term ONLY
What is Atosiban and how does it work?
selective oxytocin-vasopressin receptor antagonist
Atosiban inhibits oxytocin-induced production of prostaglandin (blank), but not prostaglandin E2. Theoretically, atosiban should be more effective at (blank) gestational ages since oxytocin receptor concentration and uterine responsiveness to oxytocin increase with advancing gestation.
F2α
later
Atosiban is not approved for fetuses less than (blank) weeks of gestation
28
What are the SEs of atosiban?
hypersensitivity and injection site reactions. No CV effects (or very minimal)
Can atosiban cross the placenta? What are the fetal effects?
Yes
unknown
(Blank) is produced in a variety of cells and is essential for maintenance of normal smooth muscle tone. (blank) is synthesized during the oxidation of L-arginine (an essential amino acid) to L-citrulline, which then diffuses from the generator cell. This reaction is catalyed by the enzyme nitric oxide synthase (NOS)>
NO
What are nitric oxide donors used for?
tocolytic
What are the maternal side effects?
-headache
-hypotension
-dizziness, flushing, palpitations
(fetal adverse effects have not been found)
What are the contraindications for NO donors?
- women w/ hypotension
- preload dependent cardiac lesions (such as aortic insufficiency)
(blank) is super used as a tocolytic and its mechanism is not really understood (competes with calcium maybe) and inhibits myometrial contraction
Magnesium sulfate
(blank) causes fewer minor maternal side effects than beta-adrenergic agonists, but the risk of major adverse risk of events is comparable. What are the most common side effects?
Magnesium sulfate
-Diaphoresis, flushing
Who can you use magnesium sulfate in?
up to 48 hours in women between 24 and 34 weeks of gestation with preterm labor
Administration of magnesium sulfate is (blank) for the neonate but only if used less than (Blank) hours.
neuroprotective
24 hours
What besides supressing labor does magnesium sulfate do? Magnesium sulfate can cause toxicity so what should you check to make sure these levels havent been reached?
How do you treat mag toxicity?
neuroprotective effects on fetus
tx of eeclampsia and preeclampsia
- always check reflexes, loss of reflex means reaching toxic doses of mag
- calcium gluconate
Magnesium is secreted by kidneys so dosing should be adjusted in women with (blank)
renal problems-> should receive maintence phase of tx only if pateller reflex is present
What are the symptoms of magnesium toxicity?
increased urine output
respirations increase
cardiac or respiratory compromise
flash pulmonary edema
What is the mechanism of action of betamethasone?
accelerate development of type 1 and type 2 pneumocytes-> changes function and structure of lungs->increases lung mechanics and gas exchange
(these changes will only happen if the fetus is old enough to respond to steroids)
(blank) exposure also enhances the neonatal response to postnatal surfactant treatment.
Antenatal steroid
What does betamethasone reduce?
- Intraventricular hemorrhage (IVH)
- Necrotizing enterocolitis (NEC)
- Neonatal mortality (NMM)
- Systemic infections (in first 48 hours of life)
what should you use with dexamethasone?
non sulfite prep
Who can you give dexamethasone to?
at least 23 weeks of gestation
(blank) is a synthetic progestogen with minimal to no androgenic activity. It is typically administered intramuscularly. Who do you use it in?
17-P
(17-Hydroxyprogesterone caproate)
-used in babies less than 32 weeks in clear preterm labor not precipitated by infection or other known cause
We suggest intramuscular injections of hydroxyprogesterone caproate rather that (blank) (Grade 2C), beginning in the second trimester (16 to 20 weeks) and continuing through the 36th week of gestation.
progesterone
How does progesterone decrease preterm labor? Who do you use it in?
decrease gap junctions-> decreases preterm labor
-women with midtrimester cervical shorterning (less than 2 mm before 24 weeks) and no prior spontaneous singleton preterm birth, tx through the 36th week of gestation.
(blank) is also known as cervix score is a pre-laborscoring system to assist in predicting whetherinduction of laborwill be required. It has also been used to assess the odds of spontaneous preterm delivery
Bishop score
What are prostaglandins used for with labor? IS it first line treatment?
induces labor
yes!
How do prostaglandins (cytotec) work?
causes dissolution of collagen bundles and an increase in the submucosal water content of the cervix
-cheap, super effective and can give them in any form
Why is cytotec (prostaglandins) given a black box warning?
because it is used in abortions
Our preferred prostaglandin for cervical ripening is (blank) administered vaginally, given available evidence of efficacy
prostaglandin E1 (misoprostol)
Who can you NOT use misoprostol (cytotek) in?
anyone with a C section because it can cause uterine rupture in people with scarred uteruses
What do you use misoprostol (cytotek) for?
labor induction and cervical ripening
A high dose of misoprostol can result in (blank)
tachysystole
(blank and blank) are two prostaglandin E2 preparations commercially available for cervical ripening in the US>
Prepidil and Cervidil
the final dose of prepidil given and initiation of oxytocin should be (blank) hours because of the potential for uterine tachysystole with concurrent oxytocin and prostaglandin administration
6 to 12
(blank) is a vaginal insert containing 10 mg of dinoprostone in a timed-release formulation (the medication is released at 0.3 mg/h). The insert is left in place until active labor begins, or for 12 hours. Oxytocin may be initiated anytime beyond 30 minutes after removal of the insert.
Cervidil®
In PGE2 preps,
An advantage of the vaginal insert over the gel formulation is that the vaginal insert can be removed in cases of (blank) or abnormalities of the fetal heart rate tracing
uterine tachysystole
(blank) make oxytocin better
Prostaglandins
(blank) is a polypeptide hormone produced in the hypothalamus and secreted from the posterior lobe of the pituitary gland in a pulsatile fashion. It is identical to its synthetic analog, which is among the most potent uterotonic agents known.
Oxytocin
Exogenous (blank) administration produces periodic uterine contractions first demonstrable at approximately (blank) weeks of gestation, with increasing responsiveness with advancing gestational age.
There is little change in myometrial sensitivity to oxytocin from (blank) to blank; however, once spontaneous labor begins, the uterine sensitivity to oxytocin increases rapidly
oxytocin
20
34 weeks to term
The gestational increase in uterine sensitivity is due primarily to an increase in (blank)
myometrial oxytocin binding sites
FDA has approved (blank) for termination of intrauterine pregnancy up to 49 days of gestation. Some clinicians use (blank and blank) for termination of pregnancy beyond 49 days of gestation.
mifepristone (mifeprex)
mifepristone and misoprostol (cytotec)
What are the two abortion protocols?
- Mifepritone followed 48 hours later by misoprostol
2. mifepristone followed 24-72 hours by misoprostol
Misoprostol (cytotec), a synthetic (blank) prostaglandin E1, is used sequentially with mifepristone (mifeprex) for first trimester medication abortion. The drug is inexpensive, can be stored at room temperature, and is widely available. Misoprostol (cytotec) is the sole prostaglandin approved by the FDA for use for medication abortion, and the FDA requires misoprostol (cytotec) be used in conjunction with mifepristone (mifeprex) for medication abortion. how should you give it?
prostaglandin E1
-buccal 1st or vaginal 2nd
why is vaginal misoprostol (cytotec) less awesome than buccal?
rare cases of clostridial sepsis
What are the SEs of misoprostol (cytotec)?
GI (n/v diarrhea) pain, vaginal bleeding
Complications include hemorrhage, infection, incomplete abortion, and unrecognized ectopic pregnancy. Rare cases of fatal sepsis have occurred.
What are the drug you use for uterus atony?
oxytocin
misoprostol (cytotec)
Methergine (methylergonovine)
hemabate (15 methyl PGF2 alpha)
What uterotonic agent cannot be used in hypertensive patients?
methergine
What is the prostaglandin that is used in atrony that you can inject straight into uterus
Hemabate (carboprost tromethamine)
What is the side affect of hemabate (carboprost tromethamine) that makes it undesirable? How do you admin this drug?
profuse diarrhea
straight into the myometrium after aspiration
