Intrapartal period Flashcards Preview

Nursing - obstetric component > Intrapartal period > Flashcards

Flashcards in Intrapartal period Deck (104)
Loading flashcards...

Definition of Intrapartal Period

From contractions that cause cervix to dilate, through delivery of neonate & placenta, +
first 1-4 hours after delivery


Theories of Labor Onset: Progesterone Deprivation Theory

Pregnancy: both estrogen and progesterone increased (from placenta), but ratio of
estrogen low: progesterone high
Estrogen stimulates, progesterone relaxes

Just before labor: ratio shifts


Theories of Labor Onset: Oxytocin Theory

Oxytocin stimulates uterine contractions, but uterus not sensitive until closer to term

Therefore, unlikely oxytocin works alone to cause labor onset


Theories of Labor Onset: Fetal Endocrine Control Theory

Anencephalic fetus: low levels fetal steroids; pregnancy prolonged
? if steroids cause release of precursors to prostaglandins, which stimulate uterus to


Theories of Labor Onset: Prostaglandin Theory

Prostaglandins: lipid substances
Induce contractions at any point in pregnancy
Used for:
1. IUFD (intrauterine fetal demise); suppository form
2. Induced abortion; injectable form
3. Cervical ripening; gel, tampon ( Cervidil), tablet forms


Labor = Myometrial Activity

Feedback loop: stretching of cervix causes increase of oxytocin, which increases
myometrial activity
Fetus distends uterus: ? relationship


In true labor, uterus divides

Upper segment: active & contractile, thickens as labor progresses
Lower segment & cervix: passive, thins and expands as labor progresses

In between 2 areas: physiologic contraction band


lower segment transverse (LST) AKA lower cervical transverse (LCT)

If patient desires trial of labor after Cesarean (TOLAC) to attempt a vaginal birth after
Cesarean (VBAC), must have this uterine incision


Vertical Uterine Incisions

Higher risk of uterine rupture with labor
In upper segment (contractile)
Will have future repeat C/S


Effacement of Cervix

Taking-up of internal os and cervical canal into uterine sidewalls
Usually precedes dilatation in primigravidas
Express in percentage: 0% - 100%
Some subjectivity



Dilation of Cervix

Longitudinal muscle fibers of uterus pull upward over baby’s head
Combined with pressure from bag of waters (BOW)
Cervix dilation from 0 cm to 10 (“complete”, “fully”)



Once completely dilated, woman pushes to expel fetus & placenta
Using intra-abdominal pressure
Must be “complete” or can bruise/tear cervix; exhaustion ensues


Pushing Causes Fetal Head to Descend to Pelvic Floor

Head meets perineal structure; pressure causes it to thin from 5 cm thick to 1 cm
Thin = less blood = natural physiologic anesthesia
Anus everts, exposing internal rectal wall


Premonitory Signs of Labor: Lightening

1. Fetus settles into inlet (becomes “engaged”)
2. Uterus seems to move downward (“dropped)
Breathe easier
More pelvic pressure
More leg cramps/pain
More venous stasis


Premonitory Signs of Labor: Braxton-Hicks Contractions

Irregular, intermittent contractions
Experienced throughout pregnancy
Pain in abdomen or groin
Can become uncomfortable
Purpose: cervical ripening


Premonitory Signs of Labor: Cervical Ripening

Ripe cervix: soft, anterior, slightly effaced and dilated
Non-pregnant: cervix feels like tip of nose
Pregnant: like lower lip
Ripe: like pudding
Ripening important re: induction decisions (unlikely to be successful if unripe)
Bishop Score: Cervical Ripening


Cervical Ripening Balloon

No drugs needed ( mechanical pressure)  
Eliminates side effects
Silicone balloons adapt to cervical contour
Easily placed & removed ( foleys can be used)


Premonitory Signs of Labor: Bloody Show

Mucus plug expelled; exposed capillaries bleed
Consistency: bloody mucus
Watery bleeding NEVER normal
Labor usually begins 24-48 hours
Confusion if recent vaginal exam


Premonitory Signs of Labor: ROM (Rupture of Membranes)

1. SROM: Spontaneous Rupture of Membranes
2. AROM: Artificial Rupture of Membranes, via amniotomy
Most common L & D procedure
No pain endings in BOW (bag of water)
Additional terms:
1. PROM: Premature Rupture of Membranes;
>1 hour from ROM to labor onset
2. PPROM: Preterm, Premature Rupture of Membranes


Prolonged ROM

anytime ROM >24 hours; increased risk of ascending infection
Chorioamnionitis: infected BOW; fever, tenderness, foul-smelling & cloudy amniotic


Sterile Speculum exam:

to check if BOW broke 


rests ½ hour
Pooling, nitrazine, ferning

Normal fluid: clear, bloody streaks; not meconium-stained or port wine color


Umbilical Cord Prolapse

Major OB emergency
R/O: after ROM, check FHTs; if low, suspect prolapse
Glove hand, insert into vagina, push upward; place patient in Trendelenburg or hands &
knees (relieve pressure on cord)


Premonitory Signs of Labor: “Nesting Instinct”

Sudden burst of energy
24 – 48 hours prior to labor
Cause unknown
Woman “feathers her nest”
Warn not to over-exert


Premonitory Signs of Labor: “Other”

1. Weight loss of 1-3 #
Fluid & electrolyte shifts
“progesterone deprivation theory”
2. More backache & sacroiliac pressure
Relaxin influencing pelvis
3. N/V, diarrhea
More room in pelvis
Clear liquid absorption unchanged; may vomit solids (aspiration risk)


True Labor

1. Cervix progressively effaces/dilates

2. Contractions regular, become closer, longer, stronger over time

3. Pain begins in back, radiates to abdomen

4. Ambulation intensifies


False Labor

1.No progressive effacement/dilation

2. Contractions irregular, do not become closer, longer, stronger

3. Pain chiefly lower abdomen or groin

4. Ambulation relieves


Stages of Labor & Birth

1. First Stage - True labor until 10 centimeters dilation

2. Second Stage - Complete dilation thru birth of neonate

3. Third Stage - Birth of neonate thru birth of placenta

4. Fourth Stage -  First 1-4 hours after delivery


Critical Factors in Labor: The 5 P’s (traditional)

1. Passageway (pelvis)
2. Passenger (fetus)
3. Powers (contractions)
4. Psyche (mental status of the woman)
5. Position (…of the woman)


Additional Critical Factors

Philosophy (low tech, high touch)
Partners (support persons)
Patience (respect for the natural timing of birth)
Patient Preparation (knowledge base)
Pain Management (comfort care)