Normal Labor Flashcards
What are the components of GTPAL?
- Gravidity
- Term
- Preterm
- Abortions
- Living children
What is AROM and SROM?
Artificial or spontaneous Rupture of Membranes
What is the definition of term?
Delivery after 37 weeks
What is the definition of preterm?
20-37 weeks
What is the definition of abortion?
Losses prior to 20 weeks
What is the definition of labor?
An increase in myometrial activity resulting in effacement and dilatation of the uterine cervix
True or false: abortions in the GTPAL include spontaneous miscarriages etc
True
What is the mean duration of a singleton pregnancy?
40 weeks from 1 day of LMP
What is the range for term babies?
36-42 weeks
How do you diagnose labor? (3)
Clinically
- Regular, painful contractions
- Progressive cervical effacement
- Bloody show
What is the definition of post-term?
Continuing beyond 42 weeks
True or false: factors responsible for the initiation and maintenance of labor at term are not well defined
True
What is phase 0 of labor? What are the three hormones utilized here?
Functional quiescence through inhibitors:
- Progesterone
- Prostacyclin
- Relaxin
What is phase 1 of labor?
Cervical softening–slow progressive structural changes of the ECM
What is phase 2 of labor? What is the major hormone here, and what does it do?
Myometrial changes–myometrial oxytocin receptors increased, causing an increase in uterine irritability and responsiveness to uterotonins
What is the lightening of labor?
Fetal presenting part descends into the pelvis
What is cervical ripening, and in what stage of labor does this occur?
Occurs in phase 2
What hormone produced by the placenta helps induce prostaglandins for contractions? What hormones withdraws at this time?
CRH
Progesterone
What are the three hormones that have an influence on phase 3 of labor?
- oxytocin influence
- prostaglandins/relaxin
What is phase 4 of labor? What is the major hormone involved?
The puerperium or postpartum interval, where the myometrium becomes rigid and in a state of constant contraction
-oxytocin
What are the 3 P’s of the mechanics of labor?
- Power
- Passenger
- Passage
What are the three descriptive characteristics of uterine activity?
- Frequency
- Intensity
- Duration
What is the classic definition of adequate uterine activity in labor?
3-5 contractions in a 10 minute period
What is the lie of the fetus? What is the best lie?
Spatial relationship of fetal spine to the maternal spine
Vertically oriented lie is optimal
What is the presentation of the fetus?
Fetal part the directed overlies the pelvic inlet
What is a compound presentation?
More than 1 fetal part presents
What is malpresentation?
Any presentation that is not cephalic with occiput leading
What are the three major lies of the fetus?
Longitudinal
Oblique
Transverse
What is longitudinal lie? Transverse? Oblique?
- Longitudinal = maternal spine and fetal spine are parallel
- Transverse= maternal spine and fetal spine are perpendicular
- Oblique = anywhere in between
What is position?
Description of the relationship between a fetal denominator (head) and the maternal pelvis
What does the middle initial stand for in the description of the position?
Fetal denominator (head)
What do the first and last initials in the description of fetal position stand for?
Maternal pelvic quadrants toward which the fetal denominator points
What is station?
Relationship of the presenting part of the maternal ischial spines
How do you communicate station?
-5 to +5, with the midpoint (0) defined as the plane of the ischial spines, and negative numbers being closer to the mother’s pelvic outlet
What is passage?
Bony and soft tissues of the maternal pelvis
What is the diagonal conjugate?
Sacral promontory to inferior margin of the pubic symphysis
What is the true (obstetric) conjugate?
-Sacral promontory to superior aspect of the pubic symphysis
What is the smallest diameter of the inlet?
True (obstetric) conjugate
What is an anthropoid pelvis?
Oval pelvic opening with the long axis in the sagittal plane
What is a gynecoid pelvis?
Circular pelvis
What is an android pelvis?
Heart-shaped pelvic opening
What is a platypelloid pelvis?
Oval pelvic opening, with the long axis in the coronal plane
What is the limiting factor in the mid cavity of the pelvis?
Interspinous diameter
What is the clinical significance of the pelvis outlet?
Rarely of clinical significance
What is the most common shape of the pelvis opening, and which is the most conducive to birth?
Gynecoid, for both
What is the first stage of labor?
Interval between onset of labor and full cervical dilation
What are the three Friedman phases of the first stage of labor?
Latent
Active
Descent
What is the latent phase of the first stage of labor? How long does this last?
Between onset of labor and a point at which a change in the slope of the rate of cervical dilation is noted
Variable duration, but hours
What is the active phase of the first stage of labor?
-Greater rate of dilatation, with onset at approximately 4 cm (highest slope on the chart)
What is the descent phase of the first stage of labor?
Usually coincides with the second stage of labor–onset between 9-10 cm
When doe active pushing occur in labor?
2nd phase
How long does the second stage of labor last for nulliparous and multiparous women?
Nulliparous = 1 hour ish Multiparous = 20 minutes ish
True or false: labors past the first labor are usually significantly shorter
Yes
What spinal levels mediate the pain of uterine contractions?
T10-L1
What are the spinal levels that mediate the perineal pain of contractions?
S2-S4
What is combined spinal-epidural analgesia?
Needle advanced into the dural space, but then a catheter is left in place to provide ongoing analgesia
What are the side effects of epidurals? (3)
- Hypotension
- Fever
- Transient fetal heart deceleration
What are the hemodynamic factors that are an absolute contraindication for epidurals?
- Refractory hypotension
- Coagulopathies
- Thrombocytopenia
Is increased ICP a contraindication to epidurals
Yes
LMH within what time frame is an absolute contraindication to neuraxial analgesia?
Within 12 hours
What is the effect of spinal analgesia on the second stage of labor?
Increases by an hour for both multiparous and nulliparous women
What is the second stage of labor?
Interval between full cervical dilatation and delivery of the infant
How do the lengths of the Third stage of labor compare for nulliparous and multiparous women
Both are 5-30 minutes
What, generally, are the cardinal movements of labor?
Changes in the the position of the fetal head during passage through the birth canal
What is the order of the cardinal movements of labor?
- Engagement
- Descent
- Flexion
- Internal rotation
- Extension
- External rotation
- Expulsion
What are the labs that should be obtained in the initial assessment of labor? (Blood x2, infectious x3)
- Type and screen
- HIV, Hep B, syphilis
- AB screen
How often should fetal heart rate be obtained during the first stage of labor? What about after a contraction?
q 30 minutes and immediately after a contraction for approx 2 minutes
How often should fetal heart rate be obtained during the second stage of labor? What about after a contraction?
q 15 minutes, and after a contraction for approx 2 minutes
True or false: pts should be NPO during labor
False- limit oral intake, but not NPO
What is the role of electronic fetal monitors during labor?
No evidence for routine use
How often should a cervical check be performed, besides at admission? (3)
- q 1-4 hours
- When patient feels urge
- Prior to analgesia
What are the two major reasons to limit cervical checks?
- Infection
- Discomfort for mom
What indicates that imminent delivery of the placenta? (3)
- Lengthening of the umbilical cord
- Gush of blood from the vagina
- Change in shape of uterine fundus
What are the two active management factors of placental delivery?
- Oxytocin
- Controlled cord traction
What is the third stage of labor? How long does this usually last?
Delivery of the placenta–10-30 minutes
