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A Bishop score greater than ? is consistent with a cervix favorable for both spontaneous labor and, as it is more commonly used, induced labor.



five components of the cervical examination

dilation, effacement, fetal station, cervical position, and consistency of the cervix


Prodromal labor or “false labor”

These patients usually present with irregular contractions that vary in duration, intensity, and intervals and yield little or no cervical change.


Labor is induced with ?

prostaglandins, oxytocic agents, mechanical dilation of the cervix, and/or artificial ROM.


A Bishop score of ? or less may lead to a failed induction as often as 50% of the time
what can be used to "ripen" the cervix?


prostaglandin E2 (PGE2) gel, PGE2 pessary (Cervidil), or PGE1M (misoprostol) or mechanical means


contraindications to PGEs

maternal: asthma, glaucoma
obstetric: prior C section, nonreassuring fetal status
*cannot turn off PGE2 gel: risk of uterine hyperstimulation and tetanic contractions: use a mechanical dilator such as a 30 cc or 60 cc Foley bulb


after amniotomy it is important not to ? in order to avoid cord prolapse

elevate the fetal head from the pelvis


the adequacy of contractions is indirectly assessed by ? and ?

the progress of cervical change


intrauterine pressure catheter (IUPC)

determines the absolute change in pressure during a contraction and thus estimates the strength of contractions


with FHR >160 bpm, what are possible concerns?

fetal distress secondary to infection, hypoxia, or anemia


Any prolonged fetal heart rate deceleration of greater than ? duration with a heart rate less than ? is of concern and requires immediate action.

2 minutes’
90 bpm


FHR variability definitions

absent (less than 3 beats per minute of variation), minimal (3 to 5 beats per minute of variation), moderate (5 to 25 beats per minute of variation), and marked (more than 25 beats per minute of variation)


a tracing can be considered formally reactive if ?

there are at least two accelerations of at least 15 bpm over the baseline that last for at least 15 seconds within 20 minutes.


early decelerations are from

increased vagal tone secondary to head compression during a contraction


Variable decelerations are a result of

umbilical cord compression


Late decelerations are a result of

uteroplacental insufficiency
They may degrade into bradycardias as labor progresses, particularly with stronger contractions.


In the case of repetitive decelerations or in fetuses who are difficult to trace externally with Doppler, a ?is often used.

fetal scalp electrode (FSE)
A small electrode is attached to the fetal scalp that senses the potential differences created by the depolarization of the fetal heart
CIs: maternal hepatitis, HIV or fetal thrombocytopenia


Category I FHR tracing

normal FHR tracing characterized by a normal baseline, moderate variability, and no variable or late decelerations.


Category II FHR tracing

indeterminate FHR tracing; a variety of tracings including those with variable and late decelerations, bradycardia and tachycardia, minimal variability, marked variability, and even absent variability without decelerations.
It is not Tier I and not Tier III, but every other fetal heart tracing.


Category III FHR tracing

abnormal fetal heart rate tracing; those with absent fetal heart variability AND recurrent late or variable decelerations or bradycardia.
the sinusoidal pattern consistent with fetal anemia is also Category III


external tocometer vs IUPC

If it is particularly important to determine the timing or strength of contractions, an IUPC may be used


Montevideo unit

an average of the variation of the intrauterine pressure from the baseline multiplied by the number of contractions in a 10-minute period
-Strength of uterine contractions can be considered adequate with greater than 200 Montevideo units


If a fetal heart rate tracing is nonreassuring, the fetal scalp pH may be obtained to directly assess fetal hypoxia and academia.
levels that are reassuring/nonreassuring?

reassuring when the scalp pH is greater than 7.25, indeterminant when it is between 7.20 and 7.25, and nonreassuring when it is less than 7.20.


The cardinal movements are ?

engagement, descent, flexion, internal rotation, extension, and external rotation (also called restitution or resolution)


first stage of labor ranges

approximately 10 to 12 (6-20 hour total range) hours in a nulli and 6 to 8 hours in a multi (2-12 hrs)


During the active phase, at least ? of dilation is expected in a nulliparous patient and ? in a multiparous patient. This minimal expectation is approximately the fifth percentile of women undergoing labor and the median rates of dilation range from ?

1.0 cm/hour
1.2 cm/hour

2.0 to 3.0 cm/hour


If the “passenger” is too large for the “pelvis,”

cephalopelvic disproportion (CPD)


Stage 2 is considered prolonged if its duration is longer than

nulli: >2 hours, >3 hours if epidural
multi: >1 hour, >2 hours with an epidural (typ.


what to do if nonreassuring fetal status i.e. repetitive late decelerations, bradycardias, and loss of variability

face mask O2, turned on left side to decrease IVC compression and increase uterine perfusion; stop oxytocin until the tracing resumes a reassuring pattern.


what to do if a prolonged deceleration is felt to be the result of uterine hypertonus (a single contraction lasting 2 minutes or longer) or tachysystole (greater than five contractions in a 10-minute period)

give a dose of terbutaline to help relax the uterus


indications for episiotomy

need to speed up delivery, impending/ongoing shoulder dystocia
-not routinely used as there is risk of lacerations increases with episiotomy esp. with medial vs. mediolateral cuts


The conditions necessary for safe application of forceps

full dilation of the cervix, ruptured membranes, engaged head and at least +2 station, absolute knowledge of fetal position, no evidence of CPD, adequate anesthesia, empty bladder, and—most important—an experienced operator.


complications of using vacuum

scalp laceration, cephalohematoma, shoulder dystocia
rare: subgaleal hemorrhage


complications of forceps

lacerations, bruising, facial nerve damage
rare: skull fracture, intracranial damage


stage 3 of labor

delivery of placenta, usually within 5-10 min of infant, up to 30 is within normal limits


give what during stage 3

oxytocin, strengthens uterine contractions to decrease placental delivery time and blood loss


The three signs of placental separation

cord lengthening, a gush of blood, and uterine fundal rebound
-don't attempt to deliver placental until all these signs are noted


retained placenta is common in ?
what can be done?

preterm/previable deliveries, placenta accreta


degrees of laceration

1st degree: involves the mucosa or skin.
2nd degree: extend into the perineal body but does not involve the anal sphincter.
3rd degree: extend into or completely through the anal sphincter.
4th degree: occurs if the anal mucosa itself is entered.


what is failure to progress or active phase arrest?

2 hours without cervical change in the setting of adequate uterine contractions in the active phase of labor
-often leads to C section but it is reasonable to wait at least 4 hours for cervical stage in the active phase of labor


most common indications for C section

breech presentation, transverse lie, shoulder presentation, placenta previa, placental abruption, fetal intolerance of labor, nonreassuring fetal status, cord prolapse, prolonged second stage, failed operative vaginal delivery, or active herpes lesions. *previous cesarean section is most common indication*


Vaginal birth after cesarean (VBAC) can be attempted if the prior hysterotomy was a ?

Kerr (low transverse incision) or Kronig (low vertical incision) without any extensions into the cervix or upper uterine segment
NOT classical hysterectomy or vertical incision through the thick upper segment of the uterine corpus


The greatest risk during a trial of labor after cesarean (TOLAC)

rupture of the prior uterine scar


signs of uterine rupture

abdominal pain, FHR decelerations or bradycardia, sudden decrease of pressure on an IUPC, and maternal sensation of a “pop.”


pain management in labor

first stage: fentanyl, Nubain, Stadol, IM morphine


pudendal block given for

operative vaginal delivery


epidural vs spinal anesthesia

spinal is given in a one-time dose directly into the spinal canal leading to more rapid onset of anesthesia, more common for C sections than vaginal


complications of epidurals and spinal anesthesia

-maternal hypotension secondary to decreased SVR, which can lead to decreased placental perfusion and fetal bradycardia
-more serious: maternal respiratory depression if the anesthetic reaches a level high enough to affect diaphragmatic innervation.
-spinal headache from CSF loss


when is general anesthesia used and what are complications

C section, especially emergent
-maternal aspiration and hypoxia to mother and fetus


Common reasons for an emergent cesarean section

abruption, fetal bradycardia, umbilical cord prolapse, uterine rupture, and hemorrhage from a placenta previa.


Labor can be induced or augmented with

prostaglandins, oxytocin, laminaria, Foley bulb, and artificial ROM.


epidurals lead to a longer ?

second stage of labor, but offers better control during crowning