Normal Labor & Delivery

Question 1

Define labor vs. false labor

Answer 1

Labor = progressive cervical dilation resulting from regular uterine contractions that occur every 5 mins and last 30-60 seconds

False labor = irregular contractions without cervical change (braxton-hicks contractions)

Question 2

Classic type of female pelvis with good prognosis for delivery vs. worst type of pelvis for delivery (poor prognosis)

Answer 2

Classic type with good prognosis = gynecoid

Poor prognosis for delivery = platypelloid (fetal head has to engage in the transverse diameter)

Question 3

Narrowest fixed distance through which fetal head must pass through during a vaginal delivery; estimated by subtracting 2 cm from the diagonal conjugate

Answer 3

Obstetric conjugate

[diagonal conjugate is approximated by measuring from the inferior portion of the pubic symphysis to the sacral promontory — if >11.5cm, the AP diameter of the pelvic inlet is adequate]

Question 4

Initial evaluation of pt presenting with signs of labor

Answer 4

Review prenatal records, identify complications of pregnancy, confirm gestational age, review lab findings

Focused hx including nature/frequency of contractions, loss of fluid, vaginal bleeding

PE: vital signs, fetal heart tones and contractions, cervical exam if appropriate

Assess fetal lie and presentation

Question 5

5 Elements of cervical exam

Answer 5

Dilation — check at level of internal os; range from closed to completely dilated at 10 cm

Effacement — thinning of the cervix reported as % change in length; range is thick to 100% effaced

Station — degree of descent of the presenting part of the fetus; measured in cm from presenting part to ischial spines beginning when bony portion of head reaches level of ischial spines; range is -5 to +5 (or -3 to +3)

Position and Consistency — used to calculated Bishop score

Question 6

4 Leopold maneuvers to evaluate fetal lie

Answer 6

1. Palpate the fundus
2. Palpate for spine and fetal small parts
3. Palpate what is presenting in the pelvis with suprapubic palpation
4. Palpate for cephalic prominence

Question 7

Types of fetal presentation

Answer 7

Face
Brow
Vertex
Breech
Shoulder

Question 8

4 stages of labor

Answer 8

Stage 1: onset of true labor to complete cervical dilation (latent phase and active phase)

Stage 2: complete cervical dilation to delivery of infant

Stage 3: delivery of infant to delivery of placenta

Stage 4: delivery of placenta to stabilization of patient

Question 9

Describe the first phase of labor in terms of latent vs. active, duration, and rate of cervical dilation

Answer 9

Latent (early labor) — period between onset of labor characterized by slow cervical dilation

Active — associated with faster rate of dilation and usually begins when cervix is dilated to 4 cm; admit for labor at this stage in term gestations

Duration of first stage is 6-8 hours in primiparas and 2-10 hours in multiparas

Rate of cervical dilation is 1.2 cm/hr in primiparas and 1.5cm/hr in multiparas

Question 10

Management of first stage of labor in terms of maternal position, fluids, labs, maternal monitoring, and fetal monitoring

Answer 10

Maternal position: pt may ambulate if head is engaged and reassuring monitoring is noted; if lying in bed encourage left lateral recumbent position

Fluids: IV used to hydrate pt, provide access to administer meds

Labs: CBC and Type and screen

Maternal monitoring: obtain vitals q1-2 hours while in labor

Fetal monitoring: can do external or internal, and either continuous or intermittent

Question 11

Management of first stage of labor in terms of uterine activity and vaginal exam

Answer 11

Uterine activity tracked via external tocodynamometer and/or internal pressure catheter (IUPC)

Vaginal exam: during active phase, should perform cervical check q2 hrs, record dilation, effacement, and station

Question 12

What does it mean if vaginal exam during stage 1 of labor is documented 4/50/-2?

Answer 12

4cm dilated

50% effaced

-2 cm station

Question 13

Benefits vs. risks of amniotomy (AROM) during first stage of labor

Answer 13

Benefits: augment labor, allows assessment of meconium status

Risks: cord prolapse, prolonged rupture associated with chorioamnionitis

Question 14

7 Cardinal movements of labor

Answer 14

Engagement — defined as presenting part at “zero” station

Descent

Flexion — changes presenting part from occipitofrontal to smaller suboccipitobregmatic

Internal rotation — usually at ischial spines, fetal head enters pelvis in transverse diameter and then rotates so occiput is either anterior or posterior

Extension — crowning occurs when largest diameter of the fetal head is encircled by the vaginal introitus (station +5); head is born by rapid extension

External rotation — delivered head now returns back to original position to align with back and shoulders

Expulsion — anterior shoulder then delivers, followed by posterior shoulder and remainder of body

Question 15

Describe management of the second stage of labor in terms of maternal position, fetal monitoring, and vaginal exam

Answer 15

Maternal position: avoid supine; dorsal lithotomy is most common for spontaneous and operative deliveries

Continuous fetal monitoring

Vaginal exam to assess descent and confirm position

Question 16

Describe delivery of the fetus during stage 2 of labor

Answer 16

Antiseptic soap used to cleanse vulvar area and drape placed under pt

As perineum becomes flattened by crowning head, an episiotomy may be warranted

To facilitate delivery of fetal head, a modified Ritgen maneuver is often performed. Once head is delivered, can bulb suction oral cavity first then nares to clear airway of blood and amniotic fluid

Use index finger to assess for nuchal cord

Deliver anterior shoulder with gentle downward traction on the fetal head. The posterior shoulder is then delivered by elevating the head

Support the baby as the body is delivered; bulb suction again if indicated; dry and stimulate, cord clamped x2 and cut; obtain cord blood specimens

Question 17

Indications for and types of episiotomy

Answer 17

Indications: likelihood of spontaneous laceration seems high; to expedite delivery by enlarging the vaginal outlet

Midline episiotomy: most commonly performed; greater risk of extension into 3rd or 4th degree tear, less postpartum pain

Mediolateral episiotomy: greater blood loss, more difficult to repair, more postpartum pain, increase risk of dyspareunia

Question 18

What is the modified Ritgen maneuver?

Answer 18

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

[Simple manual support to the perineum may be equally effective]

Question 19

4 types of perineal lacerations

Answer 19

First degree — superficial lac involving vaginal mucosa and/or perineal skin

Second degree — lac extending into muscles of perineal body bu does not involve anal sphincter

Third degree — lac extends into or completely through anal sphincter but not into rectal mucosa

Fourth degree — involves rectal mucosa

Question 20

The third stage of labor/delivery is the interval between delivery of the infant and delivery of the placenta, which usually occurs w/i 2-10 minutes. A retained placenta is diagnosed if placenta has not delivered within 30 minutes. Signs of placental separation include gush of blood from vagina, lengthening of umbilical cord, fundus of uterus rises up, and change in shape of uterine fundus from discoid to globular. Describe ways that the physician can assist with placental delivery

Answer 20

Apply counterpressure between symphysis and fundus

[do NOT pull on cord until classic signs are noted as this could result in uterine inversion]

Question 21

Management of third stage of labor after placenta has been delivered

Answer 21

Look for lacerations of cervix, vagina, and perineum

Monitor uterine bleeding

Repair episiotomies or spontaneous lacerations

Inspect the placenta for completeness

Question 22

Management of the fourth stage of labor involves close monitoring, vitals (BP and pulse), uterine fundal checks, and assessing for vaginal bleeding. Postpartum hemorrhage commonly occurs during the fourth stage. What is the most common cause of postpartum hemorrhage?

Answer 22

Uterine atony

[other causes include retained placenta and unrepaired vaginal or cervical laceration]

Question 23

Indications for induction of labor

Answer 23

Abruptio placentae
Chorioamnionitis
Fetal demise
Preeclampsia/eclampsia
Gestational HTN
Premature rupture of membranes 
Postterm pregnancy
Maternal medical conditions
Fetal compromise

Question 24

Contraindications to induction

Answer 24

Unstable fetal presentation
Acute fetal distress
Placenta previa or vasa previa
Previous C section or transfundal surgery
Any contraindications to vaginal delivery (HIV with high viral load, active HSV outbreak)

Question 25

What is the Bishop score and what is it used for?

Answer 25

Score based on cervical dilation, effacement, station, consistency, and position — used to determine if mom is favorable to induce

A Bishop score of < 6 is considered unfavorable. A score of >8 indicates probability of vaginal delivery after labor induction is similar to that of spontaneous labor.

Question 26

Cervical ripening agents and techniques

Answer 26

Cervidil (dinoprostone) — prostaglandin E2 vaginal insert; contraindicated in pts with previous C section

Cytotec (misoprostol) — prostaglandin E1 placed orally or vaginally and cannot be readily removed; contraindicated in pts with previous C section

Mechanical dilators — foley bulb catheter, laminara japonicum (dilation occurs by swelling of laminara rods)

Question 27

Only FDA approved drug for induction and augmentation of labor

Answer 27

Pitocin

[synthetic oxytocin which stimulates myometrial contractions; dosed 1-30 mu/min, uterine response w/i 3-5 mins]

Question 28

Most common side effect of pitocin (as well as some other side effects)

Answer 28

Uterine tachysystole — defined as >5 contractions in a 10min period

Other AEs: Antidiuretic effect, uterine muscle fatigue, increased risk of postpartum hemorrhage (secondary to uterine atony)

Question 29

What is important to consider prior to administering obstetric anesthesia?

Answer 29

Give IV fluids — adequate hydration is necessary to avoid hypotension and its effects on uterine blood flow

Question 30

Uterine contractions and cervical dilation result in visceral pain (T10-L1). Descent of fetal head and pressure from pelvic floor, vagina, and perineum generate somatic pain via the pudendal n. (S2-4). Regional anesthesia refers to partial or complete loss of pain sensation below T10 level. What are all the anesthesia options in labor?

Answer 30

Nonpharmacologic — lamaze, emotional support, back massage, hydrotherapy, acupuncture

Parenteral — morphine, fentanyl, meperidine, nalbuphine

Regional — local+narcotic, epidural, spinal

Local — lidocaine, pudendal block

General — usually propofol