Mod VII: The Progression of Labor - A Review

Question 1

_{Anesthesia and Analgesia for Obstetrics}

Lecture’s Objectives

Answer 1

Provide stages of labor as review

Anesthesia for vaginal delivery

Anesthesia for cesarean section

Anesthesia for non-labor procedures

Question 2

_{Stages of Labor}

By convention, labor is divided into how many stages?

Answer 2

Three stages

Question 3

_{Stages of Labor}

When does the first stage of labor starts, when does it end?

Answer 3

Starts w/ onset of true labor

Ends w/ complete cervical dilation

_{First Stage-regular uterine contractions to complete dilation}

_{The first stage is defined by the onset of true labor and ends with complete cervical dilation}

Question 4

_{Stages of Labor}

Based on the rate of cervical dilation, the first stage is further divided into which phases?

Answer 4

Latent Phase

Active Phase

Question 5

_{Stages of Labor - First stage}

The latent phase is characterized by

Answer 5

Progressive cervical Effacement

Minor dilation from 0 - 2 or 3 cm

Question 6

_{Stages of Labor - First stage}

The subsequent active phase is characterized by

Answer 6

Increased Frequency of Contractions (3–5 min apart)

Progressive cervical dilation up to 10 cm

Question 7

_{Stages of Labor - First stage}

How long does the first stage usually lasts for primapara vs. multipara?

Answer 7

8-10 hours primapara

4-5 hours multipara

Question 8

_{Stages of Labor}

When does the second stage of labor begins? when does it end?

Answer 8

Begins w/ full cervical dilation

^{(is characterized by fetal descent)}

Ends w/ complete delivery of the fetus

[Contractions during the second stage occur 1.5 to 2 min apart and last 1 to 1.5 min. Although contraction intensity does not appreciably change, the parturient, by bearing down, can greatly augment intrauterine pressure and facilitate expulsion of the fetus]

Question 9

_{Stages of Labor}

How long does the second stage of labor last?

Answer 9

10-120 minutes

Question 10

_{Stages of Labor}

When does the Third Stage of labor start? when does it end? how long does it last?

Answer 10

Starts w/ After delivery of the neonate

Ends w/ delivery of the placenta.

Last 10 - 15 minutes

Question 11

_{Stages of Labor}

What the Average Blood Loss during labor?

Answer 11

300 - 500 mL

Question 12

_{Stages of Labor}

The proces whereby the cervix stretches and gets thinner is called:

Answer 12

Effacement

Question 13

_{Stages of Labor}

Diameter opening of the cervix measured in cm is called:

Answer 13

Cervical Dilation

(measurement not precise)

Question 14

_{Stages of Labor}

What’s the sequence of Effacement & Dilation in Primaparas?

Answer 14

Primaparas Efface,

then Dilate

Question 15

_{Stages of Labor}

What’s the sequence of Effacement & Dilation in Multiparas?

Answer 15

Multiparas Efface and Dilate at same time

(Can be 75% Effaced and 3cm Dilated)

Question 16

_{Components of Labor and Delivery}

What are the Three components of labor and delivery?

Answer 16

Powers

Passageway

Passenger

Question 17

_{Components of Labor and Delivery}

Which of the three components of labor and delivery do uterine contractions and maternal expulsive efforts represent?

Answer 17

The Powers

^{(Contractions and Maternal pushing)}

Variation in onset, quality, from woman to woman

Causes retraction/dilation of the cervix and forces fetus to descend through birth canal

Question 18

_{Components of Labor and Delivery}

The Powers show Variation in onset, quality, from woman to woman - How are Powers (contractions and maternal pushing) overall lenght in Early labor? how long does each last? what are the resulting intrauterine pressures above basal tone?

Answer 18

Total lenght 5-7 minutes,

30-40 seconds each time,

Intrauterine pressures 20-30 mmHg above basal tone

Question 19

_{Components of Labor and Delivery}

The Powers show Variation in onset, quality, from woman to woman - How are Powers (contractions and maternal pushing) overall lenght in late first stage? how long does each last? what are the resulting intrauterine pressures above basal tone?

Answer 19

Total lenght 2-2.5 minutes,

last 50-60 seconds each time, and

are 40-60 mmHg above basal tone

Question 20

_{Components of Labor and Delivery}

Which of the three components of labor and delivery is made of Bony pelvis and soft tissues?

Answer 20

The Passageway

Fetus must not be mismatched with the pelvis

Question 21

_{Components of Labor and Delivery}

Which Passageway is best suited for pelvic delivery?

Answer 21

Gynecoid

(best suited for pelvis)

Question 22

_{Components of Labor and Delivery}

What should you do if Passageway concerns w/ no history patients?

Answer 22

Trial of labor

Question 23

_{Components of Labor and Delivery}

Which of the three components of labor and delivery does the fetus represent?

Answer 23

The Passenger

Question 24

_{Components of Labor and Delivery}

The relationship of long axis of fetus to long axis of mother is know as:

Answer 24

Lie

Question 25

_{Components of Labor and Delivery}

The Portion of fetus overlaying the pelvic inlet is known as:

Answer 25

Presentation

Question 26

_{Components of Labor and Delivery}

The relationship of specific fetal bony point to the maternal pelvis is known as:

Answer 26

Position

Question 27

_{Mechanisms of Labor}

What are steps in the mechanism of Labor?

Answer 27

Engagement

^{Passage of “biparietal” diameter through the plane of the pelvic inlet.}

^{Stations: -3 to +5 - Utilizes “bony point” for reference}

Descent

Flexion

Internal rotation

Extension

Question 28

_{Mechanism of Labor}

Passage of “biparietal” diameter through the plane of the pelvic inlet is also knwon as:

Answer 28

Engagement

[This is when is when the widest part of the baby’s presenting part (usually the head) enters the pelvic brim or inlet]

Question 29

_{Mechanism of Labor}

What are the Stations of Engagement?

Answer 29

-3 to +5

Fetal station refers to the level of descent (in centimeters) of the presenting part relative to the ischial spines

Question 30

_{Mechanism of Labor}

What does Engagement Utilizes for reference?

Answer 30

“Bony point”

Question 31

_{Mechanism of Labor}

Migration of the presenting part of the fetus into the birth canal is also known as:

Answer 31

Fetal Descent

Question 32

_{Stages of Labor}

Which stage of Labor is a/w Delivery of baby and the delivery of the placenta?

Answer 32

Third Stage of Labor

Question 33

_{Stages of Labor}

Why is oxytocin given in IVFs after delivery of the placenta?

Answer 33

To induce or augment uterine contractions or

To maintain uterine tone postpartum

Question 34

_{Special Situations during Labor}

What could Premature rupture of membranes (PROM) in a preterm pregnancy lead to?

Answer 34

Preterm birth

Chorioamnionitis (evaluate for it)

Await labor or onset of infection

_{[Management of PROM balances the risk of infection with the risk of fetal prematurity]}

Question 35

_{Special Situations during Labor}

What’s Chorioamnionitis?

Answer 35

Also known as intra-amniotic infection (IAI) is an inflammation of the fetal membranes (amnion and chorion) due to a bacterial infection

It typically results from bacteria ascending from the vagina into the uterus and is most often associated with prolonged labor and premature rupture of the membrane (PROM)

Question 36

_{Special Situations during Labor}

What is potentially major complication of Premature rupture of membranes (PROM) in a Term pregnancy?

Answer 36

Chorioamnionitis

Question 37

_{Special Situations during Labor}

Which drugs and therapies are used to treat Chorioamnionitis

Answer 37

Antibiotics

Oxytocin

Observation

Question 38

_{Special Situations during Labor}

What % of Term pregnancies is complicated by Premature rupture of membranes (PROM)?

Answer 38

10%

Question 39

_{Special Situations during Labor}

Elective Induction of labor can be seen as:

Answer 39

a Convenience!!!

Question 40

_{Special Situations during Labor}

What are Requirements to proceed w/ Elective Induction of labor?

Answer 40

Parous patient

Singleton vertex presentation

Gestation of 39 weeks

Favorable cervix

No contraindications to labor and vaginal delivery.

^{Amniotomy - Oxytocin}

Question 41

_{Special Situations during Labor}

When is induction of labor appropriate?

Answer 41

When indicated for both maternal or fetal reasons

Both mother and fetus must tolerate labor and delivery

^{Amniotomy alone may induce labor}

^{Cervix may not be “favorable”}

Question 42

_{Special Situations during Labor}

T/F: Amniotomy (artificial rupture of membranes (AROM) and by the lay description “breaking the water,” is the intentional rupture of the amniotic sac by an obstetrical provider) alone may induce labor

Answer 42

True

[This procedure is common during labor management and has been performed by obstetrical providers for at least a few hundred years]

Question 43

_{Special Situations during Labor}

What does it mean to an “unfavorable cervix”?

Answer 43

Cervix is high and hard and closed vs. to soft and starting to open

Cervix will be unlikely to respond if the woman is induced

_{Will need to use medication to try and make the cervix soft and start to open}

(If induction is necessary)

Question 44

_{Special Situations during Labor}

Which drugs would be administered if Cervix is not “favorable” after induction of labor?

Answer 44

Oxytocin

Topical Prostaglandin E1 analogue—Misoprostol

Prostaglandin E2–Cervadil

Question 45

_{Operative Vaginal Delivery}

Tools used for Operative Vaginal Delivery include:

Answer 45

Forceps

Vacuum

Question 46

_{Operative Vaginal Delivery}

T/F: The use of Forceps and Vacuum for operative vaginal delivery is Generally safe but need adequate anesthesia

Answer 46

True