Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
80 Cards in this Set
- Front
- Back
|
define cervical effacement
|
process by which uterine activity causes the cervix to be drawn intrabdominally into the lower uterine segment. it is also known as the thinnning or shortening of the cervix
|
|
|
labour
|
repetitive uterine contractions associated with progressive cervical effacement and dilatation
|
|
|
what is the length of human gestation
|
280 days
|
|
|
T or F a decrease in maternal progesterone is not seen at the onset of labor
|
t
|
|
|
role of PG in labor
|
PGE2, PGF2 alpha
PG is produced in the endometrium myometrium and chorioamnion arachidonic acid, a precursor to PG is stored in cell membranes labor triggers release of arachidonic acid and under the influence of COX is converted to PG |
|
|
PGE2 role in cervix
|
PGE2 and relaxin induce changes in cervix associated with cervical repening
↑collagen lysis and ↑ wateraccumulation, resultng in softening ↑ distensibility of the cervix |
|
|
PGF2 role in uterus
|
it is a potent stimulator for uterine contractions
-receptors for it are found in myometrial cell membrane and in sarcoplasmic reticulum ↑ in intracellular calcium as it is released from sarcoplasmic reticulum and from outside sources high intracellular calcium enables the sliding of actin and myosin- allowing myometrial contractions |
|
|
why are PGE2 analogues used
|
used as cervical repening agents
|
|
|
why are PG synthase inhibitors used
|
to stop preterm labor- tocolytic
Indomethacin |
|
|
what is oxytocin
|
it is a prohormone stored in posterior pituitary
|
|
|
what happens to oxytocin receptors near term
|
increases
|
|
|
sensitivity of uterine muscles to oxtocin _____ near term
|
increases
|
|
|
low levels of oxytocin present throughout pregnancy but only increase significantly when __________
|
labor has begun
|
|
|
oxytocin release from the post pit is caused by various stimuli including:
|
distension of birth canal as baby moves through it
|
|
|
where does oxytocin bind
and what does it activate |
oxytocin binds to oxytocin receptors on uterine muscle cell membrane
IP3 and DAG, IP3 induces release of calcium from sarcoplasmic reticulum |
|
|
why is synthetic oxytocin used
|
to enduce or augment labor
|
|
|
what does ethanol due to oxyocin release
|
inhibits it- tocolytic
|
|
|
oxytocin antagonis can be used as a ______
|
tocolytic
|
|
|
what are the 4 stages of labor
|
1st stage: time from onset of labor to full dilatation of the cervix
2nd stage: time from complete dilatation of the cervix to birth of the baby 3rd stage: time from birth of baby to delivery of placenta 4th stage: time from delivery of placenta to stabilization of patient- 6hrs postpartum |
|
|
name 2 phases of the first stage of labor
|
latent phase,
active phase |
|
|
Define latent phase: 1st stage
|
little appears to be happening
but contractions more coordinated, stronger and efficient cervix softening, effacement, early dilatation, and movement from anterior to posterior latent phase shorter in multiparous - 8 vs 5 |
|
|
define active phase 1st stage
|
begins when cervix is 3-4 cm dilated
dilatation occurs more rapidly faster in multiparous 6 vs 3 |
|
|
duration of 1st stage
multi and nulli |
6-18 nulli
2-10 for multi |
|
|
what is extent of cervical effacement
|
2-3 cm to paper thin
|
|
|
measurement of progress of the delivery is by
|
cervical effacement, dilatation, consistency of the cervix, position of cervix and descent of fetal head
|
|
|
range of dilatation
|
1-10 cm
|
|
|
range of consistency
|
firm, medium, soft
|
|
|
range of cervical positions
|
in relation to vagina
posterior, midposition, anterior |
|
|
descent of the fetal head
|
only occurs after full dilatation and in 2nd stage
once it begins it should be progressive measure by stations |
|
|
stations
|
relationship of presenting part of infant to an imaginary line between ischial spines
|
|
|
partogram
|
way to mark progress in dilatation and descent
|
|
|
3 PS OF MEASUREMENT OF PROGRESS
|
power passage and passenger
|
|
|
power - what can be done to improve it
|
if power of contraction is suboptimal can be improved by amniotomy if membranes are still intact
and oxytocin augmentation |
|
|
passage
|
passage or shape of maternal pelvis cannot be altered
|
|
|
what are the 4 basic types of pelvis?
|
gynecoid
android anthropoid platypelloid |
|
|
which two pelvis shapes are most conducive to labor
|
gynecoid and anthropoid
|
|
|
maternal obesity _______the likelihood of vaginal delivery
|
decreases
|
|
|
cephalopelvic disproportion
|
exists when maternal pelvis is not of sufficient size and shape to allow passage of fetal head
|
|
|
passenger
|
ability of the fetus to move through the maternal pelvis is influenced by:
-diameter of the fetal skull- depends on degree of flexion and extension -position of the head - occiput relative to pelvis -molding: fetal head's ability to change shape |
|
|
passive phase of 2nd stage
|
from full dilatation until fetal head descends to pelvic floor
active phase: bearing down efforts of woman begins with each contraction |
|
|
duration of 2nd stage
|
30 mins to 3 hours - primi
5- 30 mins for multi |
|
|
progress of second stage is protracted if:
|
<1cm/hour nulli
<2cm/hr multi |
|
|
progress of second stage is arrested if
|
no descent in one hour in nulli
or 30 mins in multi |
|
|
relationship between epidural analgesia and oxytocin
|
normally increase of oxytocin in 2nd stage
this is blocked by epidural may need to start or increase oxytocin with epidural epidural can blunt maternal bearing down efforts |
|
|
what is optimal postion for vaginal delivery
|
Occiput anterior
|
|
|
how can attendant enhance flexion or change postion
|
manually, vacuum cup, forceps
|
|
|
what is the main force driving fetus through birth canal
|
propulsive force of uterine contractions
|
|
|
mechanisms of labour
|
in order to fit through maternal bony pelvis, the fetal head goes through changes in position as it passes through the birth canal
|
|
|
name 6 mechanisms of labor
|
descent
flexion internal rotation extension external rotation expulsion |
|
|
descent
|
occurs prior to onset of labor but greater rate in latter part of first stage and in 2nd stage
in 2nd stage- maternal bearing down also contributes other cardinal movements are superimposed on descent |
|
|
flexion
|
flexion of fetal head to chest, ecouraged by resistance of cervix, walls of the pelvis and pelvic floor
-optimizes presenting diameter to maternal pelvis |
|
|
internal rotation
|
fetal head enter pelvic inlet in transverse diameter
as fetal head contacts muscular sling of pelvic floor, it rotates so occiput is turned anteriorly to ward pubic symphsis= occiput anterior allows widest part of fetal head to move through birth canal at its area of widest dimension |
|
|
extension
|
vaginal outlet curves upward and forward, so to deliver, head must move from flexion to extension
caused by downward forces: uterine contractions, and maternal effort upward forces: pelvic floor muscles |
|
|
crowning
|
when the largest diameter of the baby's head is encircled by the vaginal opening-
occurs during extension |
|
|
external rotation
|
delivered head rotates back to the transverse position allows head to once again align with fetal shoulders and back
|
|
|
expulsion
|
anterior shoulder delivers first followed by posterior shoulder - then rest of body quickly delivers
|
|
|
duration 3rd stage of labour
|
average 5-10 mins
|
|
|
signs of placental separation
|
gush of blood from vagina
umbilical cord lengthening outside vagina fundus of uterus rises up into abdomen uterus becomes firm and globular |
|
|
what period is the highest risk for post partum hemorrhage
|
4th stage- especially first hour
|
|
|
what is the most common cause of immediate post partum hemorrhage
|
uterine atony- so assess tone of uterus regularly
|
|
|
other causes of PPH
|
retained tissues, coagulopathy, laceration of the perineum, vagina or cervix
|
|
|
what is the classification for perineal lacerations?
|
first degree- includes vaginal mucosa and perineal skin
second degree- extends into submucosal vagina, or perineum, may involve muscles perineal body third degree- involves anal sphincter forth degree- involves rectal mucosa |
|
|
changes in uterus post partum
|
contractions caused by oxytocin and PGF2A minimizes blood loss- after pains
uterus loses weight 1000g at delivery to 50-100 g at 4 weeks post partum |
|
|
lochia
|
is uterine discharge caused by sloughing off of decidual tissue, epithelial cells, bacteria and RBC
lochia rubra- red 3-4 days lochia serosa- becomes paler red/pink until 9-10 day lochia alba- yellowish white, contains more wbc starts at day 10 and continuous 4-8 weeks pp |
|
|
cervix changes
|
loses its elasticity and regains its prepregnancy firmness
|
|
|
vaginal changes
|
gradually regains its former tone but never returns to pre pregnant state
|
|
|
changes in CV system post partum
|
immediately after delivery- significant increase in peripheral vascular resistance due to removal of low-pressure uteroplacental circulation
cardiac output, HR and blood volume gradually decreases to normal in 2 weeks diuresis of extracellular fluid in first week pp results in 2-3 kg weight loss |
|
|
breast changes
|
intiation of lactation requires decrease of E and P from placenta - now prolactin can act
suckling stimulates release of prolactin and oxytocin |
|
|
action of prolactin
|
milk production
|
|
|
oxytocin action
|
causes contraction of myoepithelial cells in alveoli and milk ducts known as milk ejection reflex or let down
|
|
|
colostrum
|
deep lemon yellow liquid produced 2 days pp contains minerals, aa, proteins, and Ab (IgA) IT persists for 5 days with gradual conversion to mature milk
|
|
|
what does mature milk contain
|
fat proteins vitamins and Ab
|
|
|
Postpartum blues
|
transient state of heightened emotional reactivity lasting 2-3 days but can last up to 10 days
depression, anxiety, labile poor concentration and irritability |
|
|
postpartum depression
|
develops in 10-20% within 6 mo PP
caused by genetic and environmental can escalate depressive tendencies women who experience pp dep have a greater drop in estrogen and Progesterone pp |
|
|
postpartum psychosis
|
symptoms appear rapidly first two week pp
severely depressed moods, manic symptoms, disorganized thinking, delusions, hallucinations thoughts of suicide, infanticide - emergency |
|
|
fetal hormonal changes in late pregnancy and early post partum period
|
cortisol: increases few days prior to birth converting T4 to T3- necessary for neonatal thermogenesis
huge surge of TSH causes baby to by hyperthyroid for a few days to maintain body temp increase in catecholamines: responsible for mobilizing glucose, lung fluid absorption, alteration in perfusion of organ systems, and possibly onset of respiration |
|
|
factors that influence the first breath
|
physical stimulation during delivery
deprivation of O2 and accumulation of CO2, causing increased frequency and magnitude of breathing movements, compression of chest during birth- can force fluid from respiratory tract |
|
|
transient tachypnea of the newborn
|
delay in rapid replacement of bronchial and alveolar fluid by air
|
|
|
what enables ductus arteriosus to close
|
as fluid is replaced by air, compression of pulmonary vasculature, results in decreased resistance to pulmonary arterial blood flow and blood pressure enabling ductus arteriosus to close
|
|
|
what does surfactant do
|
synthesized in TII pneumocytes - lowers alveolar surface tension and prevents collapse of lung with each expiration
|
