Labor and Delivery (NOT FINISHED) Flashcards
What is the weird word for the postpartum period up to 6 weeks after delivery that Herrick and Shamblen insisted we know?
Puerperium
Uterine activity that results in progressive dilation and effacement of the cervix
Labor
Opening of the cervical os
Dilation (estimated in cm)
Thinning of the cervix described as a percentage of a normal ____ long cervix
Effacement
4 cm
Placement of the presenting part in the maternal pelvis in relation to the ischial spines
Station
Usually divided into thirds
Fully dilated is ______ cm
10cm
The evaluation for rupture of membranes includes a ____________ which attempts to visualize a pool of fluid and obtain a specimen of vaginal fluid for testing
STERILE speculum exam
Must be sterile b/c you don’t want to introduce bacteria into the amniotic sac
Direct testing methods for determining if membranes have ruptured
“Fern” testing
Amniosure testing
Nitrazine paper (no one uses this anymore except the old docs)
Supportive test: Amniotic fluid index (AFI) by U/S
Amniotic fluid is mostly just a bunch of…
Baby piss
How does the nitrazine paper testing work
It’s essentially ph testing
Normal vaginal pH is 3.5-4.5 (b/c of lactobacilli)
Paper will turn blue in presence of alkaline amniotic fluid
93.3% sensitive
What can cause false positives on nitrazine paper?
Urine
Blood
Semen
BV
Trichomoniasis
What is fern testing?
Air dried sample of vaginal fluid on a slide —> characteristic “fern” pattern if membranes have ruptured
Very specific but not very sensitive
Does a patient whose membranes have ruptured need to be admitted to the hospital if she’s not in active labor?
YES
The part of the baby coming 1st through the birth canal
Presentation
Ex:
Cephalic
Breech
Position of the long axis of the fetus with respect to the long axis of the mother’s body
Lie (ie Transverse lie)
Station is typically measured in _______ compared to the ________
1/3’s (occasionally 1/5’s)
Ischial spine
(Ischial spine = 0)
When the baby’s head is at +3…
You can see the baby’s scalp by spreading the labia majora
Evaluation of labor should include…
Review of medical/obstetric hx
Obtain mom’s description of her contractions
Vital signs
Cervical exam
Fetal evaluation
Status of membranes
Contraction activity
Describe Stage 1 of labor
Contractions accomplish complete dilation and effacement
What are the subdivisions of Stage 1 of labor?
Latent - slower, less predictable; typically 0-5cm dilation
Active - faster, more predictable; typically 5-10cm dilation (admit them at this point)
Describe Stage 2 of labor
“The pushing stage”
Uterine contractions and maternal effort cause expulsion of the fetus
Describe Stage 3 of labor
“The medical student stage”
The placenta becomes detached from uterine wall and is expelled
Describe Stage 4 of labor
~2 hours post delivery of placenta, many hemodynamic changes
Name that labor stage:
Contractions accomplish complete dilation and effacement
Stage 1
Name that labor stage:
Uterine contractions and maternal effort cause expulsion of the fetus
Stage 2
Name that labor stage:
The “pushing” stage
Stage 2
Name that labor stage:
The placenta becomes detached from the uterine wall and is expelled
Stage 3
Name that labor stage:
The “med student” stage
Stage 3
Normal length of first stage of labor varies between ______ but not by ______
Parity - Multiparas will USUALLY deliver faster than nulliparas (never delivered a baby)
Race/ethnicity
Second stage of labor varies by…
Both race and parity
Caucasians typically longer, African Americans shortest, Hispanics in the middle
Signs of second stage of labor
Maternal urge to push (defecate)
Nausea
Emesis
Changes in the position of the fetal head in relationship to fetal body as it navigates the maternal pelvis
Cardinal movements of labor
What is the narrowest diameter of the fetal head?
The suboccipital or Bregmatic diameter (~9.5cm)
What are the six cardinal movements of labor?
Engagement Flexion Descent Internal Rotation Extension External Rotation
What is Engagement?
Passage of the widest diameter of the presenting part to a level below the plane of the pelvic inlet
When does the fetus present the smallest diameter of its head?
During flexion (second cardinal movement of labor)
With head completely flexed, the bregmatic diameter is presented
When does the greatest rate of descent occur?
During the latter portions of 1st stage of labor and during 2nd stage of labor
This is the third cardinal movement of labor
What happens during the internal rotation (4th) cardinal movement of labor?
Rotation of the presenting part from its original position (usually transverse) to anteroposterior position (ideally) as it passes through the pelvis
When does extension occur during the cardinal movements of labor?
5th cardinal movement
Once the fetus descends to the level of the intro it’s, the head extends beneath maternal pubic symphysis and head is delivered
What is the last cardinal movement of labor?
The head rotates 45 degrees to line up with shoulders which are oblique in maternal pelvis
Interval between delivery of the fetus and delivery of the placenta
Third stage of labor
What is the major complication during the third stage of labor?
HEMORRHAGE
Others:
Retention of the placenta
Uterine inversion
How long does the third stage of labor typically last?
30 min or less, but often aided by labor attendant
What are some potential causes of hemorrhage during the third stage of labor?
Infection
Prolonged labor
Large or multiple fetuses
What is the big thing you want to avoid with assisted removal of the placenta?
Avoid uterine eversion
If uterus is not yet firm and you pull on the cord like a dumbass med student —> EMERGENCY —> immediate shock —> death
What are the signs of separation of the placenta?
- Uterus rises in the abdomen
- Globular configuration
- Gush of blood
- Lengthening of umbilical cord
Not clinically important but your preceptor will think you’re hot shit if you can recite these…
What occurs during the fourth stage of labor?
Interval btwn delivery of the placenta and the subsequent 2 hours postpartum
MAJOR HEMODYNAMIC CHANGES with maternal CV system
“Transfusion” from the now contracted uterus
Particularly critical time for women with CV or pulm diseases
What are the 3 P’s for monitoring the progress of labor?
Power (maternal efforts and uterine contractions)
Passenger (size/position of fetus)
Passage (size/shape of maternal pelvis)
Uterine contractions increase in frequency and intensity due to increases in _________
Prostaglandins
Power of uterine contractions comes from increased sensitivity of the uterine muscle fibers to …
Circulating oxytocin, produced by the hypothalamus and secreted by pituitary
What is considered adequate labor in terms of contractions?
3-5 contractions in 10 min averaged over 30 min
How is uterine power quantified?
Using an internal monitor
Adequate labor = 200 MVu
Maternal expulsion efforts are affected by…
Maternal strength
Consciousness/sedation
Pain
Regional anesthesia (epidural or spinal)
________ measures the frequency and duration of contractions but not intensity
External tocodynamometer
Intensity can be masked by patient body habits or maternal movements such as cough
_______________ measures frequency, duration, and intensity of contractions
Internal tocodynamometry
What method is used to directly and more precisely measure the intensity or strength of contractions?
Internal tocodynamometry with an intrauterine pressure catheter (IUPC)
What is a macroscopic infant?
> 4500 grams
“A large passenger” may affect progression of labor
What are some possible presentations a fetus may have?
Cephalic (vertex)
Breech (Frank, complete, footling)
Brow, face compound
Shoulder
Transverse lie
What are Leopold’s Maneuvers?
Used to external manipulate a baby with a non-Cephalic presention to try to get them into Cephalic
Relation of the fetal presenting part to the right or left side of the maternal pelvis
Position
With is the most common fetal presenting position?
Left occiput anterior (LOA)
What are the three passageway considerations?
Inlet
Midpelvis
Outlet
What are the boundaries of the pelvic inlet?
Pubic symphysis (top)
Sacral promontory (posterior)
Pectinate lines (lateral)
What are the boundaries of the midpelvis?
Midpoint of symphysis (top)
Midpoint of sacral curve (posterior)
Ischial spines (lateral)
What are the boundaries of the outlet?
Inferior border of symphysis (anterior)
Tip of sacrum (posterior)
Ischial tuberosities (lateral)
What are the four basic female pelvic types?
Gynecoid
Anthropoid
Android
Platypelloid
Which pelvic type is most common and best for delivering bebes
Gynecoid
Wide forepelvis
Straight side walls
Wide subpubic arch
Which pelvic type is most unfavorable for delivery?
Android
Which pelvic type will usually prolong labor and will commonly lead to occiput posterior presentation?
Anthropoid
Which pelvic type is least common?
Platypelloid
Describe true labor
Regular intervals, gradually increasing in frequency
Increasing intensity
Cervical dilation occurs
Back and abdominal discomfort
Labor pattern not altered by analgesia
Describe false labor
Irregular intervals and duration, Braxton hicks contractions
Intensity usually varies (up and down)
No cervical change over reasonable time
Back and abdominal discomfort
Usually relief from sedation or hydration
What are the different options for fetal monitoring?
Intermittent auscultation
Continuous electronic fetal monitoring (CEFM)
• External - ultrasonographic transducer on abdomen
• Internal - scalp electrode ECG
What are we trying to measure with fetal monitoring?
Baseline fetal HR (should be 110-160bpm)
Variability in HR (absent, minimal, moderate, or marked)
Periodic changes (accelerations/decelerations)
Contraction pattern
What kind of variability in HR do you want to see with fetal monitoring?
Moderate (6-25 bpm change around baseline)
Absent variability = hypoxia = bad
Early decelerations in fetal HR mirror…
Shape of contraction, due to head compression
This is physiologic
Variable fetal HR decelerations are due to …
Cord compression
Variable timing with relation to the contraction, shape and severity also variable
Late decelerations in fetal HR are due to…
Fetal hypoxia
Can be the result of placental insufficiency, maternal hypotension, or hypoxia
An ominous sign
What are the indications for basic antepartum testing?
To evaluate a fetus who is at a higher than normal risk for intrauterine fetal complications that can lead to placental insufficiency and fetal acidosis
What are the different components of basic antepartum testing?
Fetal kick counts
Non-stress testing
Contraction stress testing
Biophysical profile
What do we want to see on a non-stress test?
2 accelerations within 30 min associated with movement
What are the parameters included in the biophysical profile?
U/S evaluation of:
• Amniotic fluid assessment - Deepest Vertical Pocket of 2 cm
• Gross fetal movement
• Tone (Flexion/extension of fetal joints)
•Fetal “breathing” activity sustained for 30 sec
Each of thesis is counted as +2 if present and 0 if absent
Max score is 10
What is considered a negative (reassuring) result for contraction stress test?
Three contractions in 10 min with no late decelerations
What is considered positive (non-reassuring) during the contraction stress test?
Late decelerations or significant variable decelerations with greater than 50% of the contractions in a 10 min period
What is considered an equivocal result for the contraction stress test?
Late decelerations with less than 50% of the contractions in 10 min
What classification of obstetric laceration:
Involves the vaginal mucosa or perineal skin but not the underlying tissue
First degree
What classification of obstetric laceration:
Involves the underlying subQ tissue but not the rectal sphincter or rectal mucosa
Second degree
What classification of obstetric laceration:
Extends through the rectal sphincter but not into the rectal mucosa
Third degree
What classification of obstetric laceration:
Extends into the rectal mucosa
Fourth degree
What is an episiotomy?
A surgical incision of the perineum and the posterior vaginal wall during the second stage of labor to quickly enlarge the opening for the baby to pass
What can be used to induce labor?
Prostaglandin gel or other device
Misoprostol (Cytotec)
Pitocin (mimics oxytocin)
“Stripping” membranes
Amniotomy (artificial rupture of membranes)
What is uterine tachysystole?
Contraction frequency 5+ contractions in 10 min averaged over 30 min
Risk of induction
What are the complications of uterine tachysystole?
Can cause decreased oxygen exchange and risk of fetal hypoxia/acidosis
What are the risks of labor induction?
Uterine tachysystole —> fetal hypoxia/acidosis
Increased risk of cesarean delivery, esp with “unfavorable cervix”
Umbilical cord prolapse with amniotomy w/ unengaged presenting part
Intra-amniotic infection b/c of multiple exams or prolonged labor time
What is the scoring system used to determine if a mother is a good candidate for induction of labor?
Modified Bishop scoring system
Points 0-3 for • Dilation • Effacement • Station • Cervical consistency • Position of the cervix
Bishop score of 9-13
Highest likelihood of successful induction
Bishop score of 0-4
Highest likelihood of failed induction
What are the benefits of labor induction?
Ending a pregnancy when fetal or maternal risk of continuing the pregnancy is increased (IUGR, pre-eclampsia, etc)
Convenience in scheduling (mom or doc)
Often controversial
What are the different options for OB anesthesia?
Psychoprophylaxis (Lamaze, relaxation, hypno-birthing)
Intravenous narcotics or tranquilizers
Epidural
Spinal (used for cesareans)
Inhaled NO
General (if complications)
What anatomic changes occur during the puerperium?
Uterus involuted from 1000gm to 50-100gm
Cervix loses marked vascularity, glandular hypertrophy
Ovarian function is quiescent; ovulation may be delayed from 6-12 weeks
Hormonal changes affecting most of the other systems
Vaginal vault decreases in size but walls are thin, inelastic, and can be dry until ovulation resumes
Puerperium management usually includes…
Hospitalization x1-2 days for vaginal birth, x2-4 days for C/S
Physical activity
Sexual activity
Work
Postpartum exam at 4-6 weeks (discuss family planning)
Breastfeeding pros and cons and lactation counseling
Psychosocial changes
When does breast milk come in?
Colostrum after 1st day
Mature milk after 3rd-5th day
Monozygotic twins are also called…
Identical twins
Dizygotic twins are also called…
Fraternal twins
What type of twins:
Identical genotype
Monozygotic
What type of twins:
Separate genotype
Dizygotic
What type of twins:
No genetic predisposition
Monozygotic
What type of twins:
Genetic predisposition
Dizygotic
What type of twins:
No increased risk with fertility treatment
Monozygotic
What type of twins:
Increased risk with fertility treatment
Dizygotic
What are the three types of monozygotic twins?
Monoamniotic/monochorionic
Monoamniotic/dichorionic
Diamniotic/dichorionic
Which type of twin gestation is least high risk?
Dizygotic twins
But they do have risks: • Preterm labor and delivery • Intrauterine growth restriction • Increased risk of fetal anomalies • Increased risk of C/S
Why are monozygotic twin gestations more risky?
Twin-twin transfusion
Cord entanglements
Increased risk of growth restriction and preterm birth
Condition where arteriovenous malformations occur in the placenta of a monochorionic/diamniotic pregnancy
Twin to twin transfusion syndrome
One becomes anemic and one becomes polycythemic
One becomes fluid overloaded and polyhydramnios, the other becomes oligohydramnios
When does twin to twin transfusion syndrome usually present?
In the second trimester
Serial U/S eval every 2 weeks beginning at 16 weeks should be considered
