Normal Labor and Delivery

Question 1

Definition of labor:

What is false labor?

Answer 1

Progressive cervical dilation resulting from regular uterine contractions that occur at least every 5 min and last 30-60 sec.

False labor (Braxton-Hicks contractions) are irregular contractions without cervical change.

Question 2

What composes the anterior and posterior fontanelles?

Answer 2

Anterior: parietal bones and frontal bones; creates a diamond shape measuring approx. 2x3 cm.

Posterior: occipital bone and parietal bones; Y or triangle shape

Question 3

When the baby’s head is flexed, what is part of the head is presented? What is the width?

When the baby’s head is deflexed (extended), what is part of the head is presented? What is the width?

What is the widest width presentation?

Answer 3

Suboccipitobregmatic (occiput anterior) - 9.5 cm

Occipitofrontal (occiput posterior) - 11 cm

Supraoccipitomental (chin to posterior head) - 13.5 cm

Question 4

Gynecoid pelvis exists in what percentage of women?

Characteristics include:

How does the head present?

Prognosis for delivery?

Answer 4

50% - most common

Round at the inlet, wider transverse diameter than A/P diameter, wide suprapubic arch (>90 degrees)

Head rotates occiput anterior

Good prognosis

Question 5

Android pelvis occurs in what percentage of women?

Characteristics include:

How does the head present?

Prognosis for delivery?

Answer 5

30% of females - classic male pelvis

Widest transverse diameter is closer to sacrum, prominent ischial spines, narrow pubic arch

Head if forced occiput posterior

Poor prognosis - the space is restricted and arrest of descent is common

Question 6

What is the head position and prognosis for delivery of anthropoid pelvis?

What is the head position and prognosis for delivery of platypoid pelvis?

Answer 6

Anthropoid: OP position and good prognosis

Platypoid: transverse position (looking laterally) and poor prognosis

Question 7

How is diagonal conjugate measured? What length is adequate?

How is obstetric conjugate measured?

How can you palpate to asses the female pelvis?

Answer 7

Diagonal: measure from inferior portion of pubic symphysis to sacral promontory. If the A/P diameter is >11.5 cm, it is adequate.

Obstetric: estimated by subtracting 2 cm from diagonal conjugate. It is the narrowest distance that the fetal head must pass through.

Palpate the anterior surface of the sacrum (usually concave) and ischial spines to assess prominence.

Question 8

What measurements are needed to assess the pelvic outlet? (3)

Answer 8

Ischial tuberosities and pubic arch

Measure between ischial tuberosities (8.5 cm is OK)

Infrapubic angle (>90 degrees)

MRI/CT can be done (rare)

Question 9

Fetal lie

Answer 9

Determined by fetal spine and maternal spine positioning (longitudinal, transverse or oblique)

Question 10

What is the series of Leopold maneuvers? (4)

Answer 10

1. Palpate fundus of uterus (head, butt, transverse, etc.)
2. Palpate for fetal spine and “small parts”
3. Palpate what is presenting to pelvis in suprapubic positioning
4. Palpate for cephalic prominence (chin, occiput, etc.)

Question 11

Fetal presentation

Answer 11

Presenting part to the pelvis (vertex, breech, transverse or compound (vertex w/ hand))

Question 12

Cervical exam

Dilation

• checked where?
• what is the range of dilation?

Effacement

• how is it reported?
• what is the range?

Station

• what is it?
• how is it measured? (what is = 0?)
• what is the range?

Consistency and position
-what is it used for?

Answer 12

Dilation

• checked at level of internal os
• ranges from closed to completely dilated at 10 cm

Effacement

• % change in length
• range is from thick to 100% effaced

Station

• degree of descent of the presenting part of the fetus
• measured form the presenting part to the ischial spines; 0 = bony portion of head is at the ischial spines
• range is -5 to +5

Consistency and position is used to calculate Bishop score

Question 13

What are the first, second, third and fourth stages of labor?

Answer 13

1st stage: onset of true labor to cervical dilation (latent phase and active phase)

2nd stage: complete cervical dilation to delivery of infant

3rd stage: delivery of infant to delivery of placenta

4th stage: delivery of placenta to stabilization of patient

Question 14

Latent vs. active labor

Answer 14

Latent: period between onset of labor and is characterized by slow cervical dilation.

Active: a faster rate of dilation and begins when cervix is dilated to 6 cm (admit for labor at this stage)

Question 15

What is the duration of the 1st stage of labor in primiparas vs. multiparas?

What is the rate of cervical dilation in primiparas vs. muliparas?

Answer 15

Duration

• primiparas: 6-18 hrs
• multiparas: 2-10 hrs

Rate of cervical dilation

• primiparas: 1.2 cm/hr
• multiparas: 1.5 cm/hr

Question 16

How often should vitals be taken during labor?

Answer 16

q1-2 hrs

Question 17

External intermittent monitoring in an uncomplicated pregnancy in the active phase (1st phase) and 2nd phase of labor is done how often?

In a complicated pregnancy?

When is continuous monitoring a good idea?

Answer 17

Uncomplicated

• active phase of 1st stage: q30 min
• 2nd stage: q15 min

Complicated

• active phase of 1st stage following a contraction: q15
• 2nd phase: q5 min

Continuous monitoring is useful if the pregnancy is at a very high risk

Question 18

What kind of monitoring provides the most accurant tracings?

Answer 18

Internal monitoring

Question 19

What does an intrauterine pressure catheter (IUPC) help with?

When is it used?

Answer 19

Allows you to assess the strength of contractions and helps with oxytocin augmentation.

It is used in the 1st stage.

Question 20

During the active phase, how often should the cervix be checked?

Interpret the following: 4/50/-2

Answer 20

q2 hrs

4/50/-2: 4 cm dilated/50% effaced/-2 cm station

Question 21

What are benefits of amniotomy (AROM - “breaking the water”)?

Risks?

When is it done?

Answer 21

Benefits: augment labor, allows assessment of meconium status

Risks: cord prolapse, prolonged rupture is associated with chorioamnionitis (infection of fetal membranes)

1st stage

Question 22

What is seen in the mother by the 2nd stage of delivery?

What is the duration for the following:

• primapara w/o epidural
• primapara w/ epidural
• multipara w/o epidural
• multipara w/ epidural

Answer 22

Increased bloody show and desire to bear down with each contraction.

• primapara w/o epidural: 2 hrs
• primapara w/ epidural: 3 hrs
• multipara w/o epidural: 1 hr
• multipara w/ epidural: 2 hrs

Question 23

What maternal position should be avoided in the 2nd stage? What position should be engages?

How often should the patient be monitored in the 2nd stage if there are no risk factors?
What if there are some obstetric risk factors?

Answer 23

Avoid supine position. Dorsal lithotomy position is most common.

No risk factors: q15 min
Risk factors: q5 min

Question 24

If the nuchal cord is loose, then…

If it is tight, then…

Answer 24

Loose - manually reduce over baby’s head

Tight - clamp x2 and cut

Question 25

Indications for episiotomy (2)

What are characteristics of the midline and mediolateral episiotomy?

Answer 25

Likelihood of spontaneous laceration seems high
To expedite delivery by enlarging vaginal outlet

Midline: most common, greater risk of extension, less postpartum pain
Mediolateral: greater blood loss, more difficult to repair, more postpartum pain, increased risk for dyspareunia

Question 26

How is the modified Ritgen maneuver performed?

Answer 26

Fingers of right hand are used to extend the head while counterpressure is applied to the occiput by the left hand to allow for a more comfortable delivery

Question 27

Describe the following lacerations:

1st degree
2nd degree
3rd degree
4th degree

Answer 27

1st degree: a superficial laceration involving the vaginal mucosa and/ perianal skin

2nd degree: laceration extends into the muscles of perineal body, but does not involve anal sphincter

3rd degree: laceration extends into or completely through the anal sphincter but not into the rectal mucosa

4th degree: involves rectal mucosa

Question 28

What is the duration of the 3rd stage?

At what point is it determined that the placenta is retained?

Answer 28

2-10 min usually

If placenta is not delivered by 30 min

Question 29

Classic signs of placental separation include…

What MUST you do when delivering the placenta?

Answer 29

Gush of blood from vagina
Lengthening of umbilical cord
Fundus of uterus rises
Change in uterine shape

Apply some counter-pressure between symphysis and fundus to avoid uterine inversion

Question 30

Management of 3rd stage includes… (4)

Answer 30

Look for lacerations
Monitor uterine beeding
Repair episiotomy/lacerations
Inspect placenta for completeness

Question 31

When does post-partum hemorrhage occur?

What are 3 major causes?

Answer 31

3rd stage

Uterine atony, retained placenta, unrepaired vaginal/cervical laceration

Question 32

4 contraindications to induction

Answer 32

Unstable fetal presentation
Acute fetal distress
Placenta previa or vasa previa
Previous classical C-section

Question 33

What is a Bishop score?

Bishop score < 6 =
Bishop score > 8 =

Answer 33

Helps predict whether induction of labor will be required

< 6 = considered unfavorable
> 8 = probablility of vaginal delivery after labor induction is similar to that of spontaneous labor

Question 34

Cervical ripening agents (MOA, route of admin, contraindications)

Cervidil

Cytotec

Answer 34

Cervidil: PGE2, vaginal insert, contraindicated if pt. had a prior C-section

Cytotec: PGE1, placed orally or vaginally, downside is that it cannot be reomved if concerns arise, contraindicated in a pt. with prior C-section

Question 35

What are 2 mechanical dilators used to help ripen the cervix?

Answer 35

Foley bulb catheter
Laminara Japonicum (dilation occurs by swelling of laminara rods)

Question 36

What is Pitocin? How is it administered?
What is the dosing?

3 complications of its use:

Answer 36

A synthetic oxytocin which stimulates myometrial contractions. Administered via IV.
Dosed 1-
*only drug FDA approved for induction and augmentation mu/min

Uterine tachysystole (>5 contractions in 10 min period)
Anti-diuretic effect
Uterine muscle fatigue (non-responsiveness)

Question 37

What is a risk for obstetric analgesia? What must be given with it?

Answer 37

It can decrease uterine blood flow if hypotension occurs and is not treated promptly.
Must give IV hydration.

If hypotension does occur, a vasopressor (ephedrine) can be given to restore maternal blood flow and uterine flow.

Question 38

Uterine contractions and cervical dilations result in what kind of pain via which spinal levels?

Pain in the pelvic floor, vagina and perineum can generate what kind of pain via which nerve/levels?

Answer 38

Visceral pain via T10-12 through L1

Somatic pain via pudendal n. (S2-S4)

Question 39

What is regional anesthesia?

Answer 39

Partial or complete loss of pain sensation below T10 level

Question 40

When are parenteral meds (morphine, fentanyl, etc.) most helpful?

What are downsides? (2)

Answer 40

Early 1st stage when pain is more visceral and less severe.

They have little efficacy for relief of labor pain.
Opioids easily cross the placental barrier and may lead to neonatal respiratory depression.

Question 41

Regional anesthesia results in loss of pain where?

Where is an epidural placed?

What is the indication for a spinal injection?

Answer 41

Loss of pain below T8-T10

Epidural placed between 2 lumbar vertebra and a catheter is placed for continuous infusion.

Spinal is a single shot that is often used in planned C-sections.

Question 42

Benefits of regional anesthesia include..

Side effects include…

Contraindications include…

*be broad

Answer 42

Benefits: effective, mother is alert and will remeber experience.

SE: *hypotension, spinal HA, fever, hematomas, spinal abscesses

Contraindications: maternal coagulopathy. recent Heparin use, infections, increase intracranial pressure

Question 43

When should local anesthesia of perineum be done?

Answer 43

When there is prep for episiotomy or laceration repairs

Question 44

Most common induction agent used:

What are the issues with it? (3)

When is it indicated? (2)

Answer 44

Propofol

Mother loses consciousness
16x increase risk of anesthesia related maternal mortality
Readilt crosses placenta and has been associated with neonatal respiratory depression

Commonly performed is rapid delivery is needed (emergent) or regional anesthesia has failed