Dysfunctional Labor (Moulton)

Question 1

Uterus is a large smooth muscle organ composed of billions of smooth muscle cells. Each of these cells becomes a contractile element when the intracellular ionic __1__ concentration increases to trigger an enzymatic process that results in the formation of the __2__ element.

Stimulation of __3__ receptors on the plasma membrane further activates the __2__ element.

Contractions occur in localized areas during gestation but during labor the entire uterus contracts in an organized fashion. These coordinated smooth muscle cells contractions are secondary to the __4__ that activate the movement of action potentials throughout the myometrium.

Answer 1

1) Calcium
2) Actin-myosin
3) Oxytocin
4) Gap junctions

Question 2

Relaxation of the uterus is maintained by factors that increase levels of __1__.

Contraction of the uterus is from the increase intracellular __2__ stores which promotes interaction of __3__ and __3__ causing uterine contractions

Answer 2

1) Cyclic adenosine monophosphate (cAMP)
2) Calcium
3) Actin and myosin

Question 3

1) During labor, what are the two distinct segments of the uterus are that are formed?
2) What happens to each?

Answer 3

1) Upper-contract/retract to release fetus

2) Lower-cervix thinner (and passive)

Question 4

What does the cervix contain?

Answer 4

Collagen and smooth muscle

Question 5

In labor the cervix changes from firm, intact sphincter to soft, pliable, dilatable structure.
These structural changes are the result of
1)
2)
3)

Answer 5

1) Collagenolysis
2) Increased Hyaluronic acid
3) Decreased Dermatan sulfate (which favors increased water content)

Question 6

In the first stage of labor, the latent phase is characterized by cervical softening and effacement occur with minimal dilation which is defined as less than __1__ cm.

The active phase starts when the cervix is dilated to __1__ cm.

Answer 6

1) 6 cm

Question 7

For all phases of labor (except the latent phase) an abnormality may be defined as either protraction or arrest. What does each mean?

Answer 7

1) Protraction: Slower than normal rate

2) Arrest: Complete cessation of progress (no further dilation or descent)

Question 8

An arrested latent phase implies that?

Answer 8

Labor has not begun

Question 9

What are the Normal length of the latent phase in

1) Nulliparous mother
2) Multiparous mother

Answer 9

1) 20 hours

2) 14 hours

Question 10

1) What is the effect of prolonged latent phase with perinatal mortality?
2) What are the causes of prolonged latent phase?

Answer 10

1) NONE

2) Excessive use of sedatives/analgesics
Fetal malposition

Question 11

1) In management of prolonged latent phase, what can help distinguish true vs false labor?
2) What drug can be given that will progress the patient to the active phase or will stop contractions due to the patient undergoing false labor?

Answer 11

1) Sleep

2) Morphine

Question 12

ACTIVE PHASE-Cervical Dilation

1) What is Normal nulliparous cervical dilation?
2) What is Normal multiparous cervical dilation?

Cervical dilation of less than the norms constitutes a __3__ disorder of dilation of the active phase.

If 2 or more hours elapsed with no cervical dilation an __4__ disorder of dilation has occurred.

Answer 12

1) 1.2 cm/hr
2) 1.5 cm/hr
3) Protraction
4) Arrest

Question 13

FETAL DESCENT-Active Phase

1) What is Normal nulliparous descent?
2) What is Normal multiparous descent?

Fetal descent of less than the norms constitutes a __3__ disorder of descent of the active phase.

If no change in descent/station has occurred within 1 hr an __4__ disorder of descent has occurred.

Answer 13

1) 1 cm/hr
2) 2 cm/hr
3) Protraction
4) Arrest

Question 14

1) ____ is defined “difficult labor” it can be used interchangeably with dysfunctional labor characterizing that labor is not progressing normally.
2) What are the three P categories?

Answer 14

1) Dystocia

2) Power- Is contraction strong?
Passenger- How big is baby?
Passage-Is the pelvic bone too small?

Question 15

The diagnosis of dystocia should NOT be made before what has been tried?

Answer 15

An adequate trial of labor

Question 16

__1__ refers to stimulation of uterine contraction when spontaneous contractions have failed to result in progressive cervical dilation or descent of the fetus.

This should be considered if

2) Contractions are less than what in 10 minute period?
3) and/or the intensity is less than what?

Answer 16

1) Augmentation
2) Three
3) 25 mm/Hg

Question 17

What is recommended in protraction and arrest disorders after assessing

• Maternal pelvis
• Fetal position
• Station
• Maternal/fetal status

Answer 17

Oxytocin

Question 18

The intrauterine pressure catheter (IUPC) is a soft plastic catheter placed transcervically that gives precise measurement of the __1__ of the uterine
contractions in mmHg.

2) What is required for this?
3) What can Intrauterine pressure catheter be used to assess?

Answer 18

1) Intensity
2) Ruptured membranes
3) Power

Question 19

Minimal effective uterine activity is defined as?

Answer 19

3 contractions in a 10 minute period averaging 25 mmHg above baseline

Question 20

1) What is the Benefit of Artificial Rupture of membranes

2) What are the risks?

Answer 20

1) Augment Labor

2) Cord prolapse and Chorioamnionitis

Question 21

What is the only FDA approved medicine for labor stimulation due to inadequate uterine contractions?

Answer 21

Pitocin (oxytocin injection)

Question 22

1) What is Cephalopelvic disproportion?
2) This causes a failure of what?
3) Who is most at risk?
4) Which P of the Active Phase does this assess?

Answer 22

1) Disparity between pelvis and fetal head
2) Failure of Descent
3) Nulliparous
4) Passage

Question 23

Presentations other than vertex __1__ position are considered to be abnormal in the laboring patient.

Fetal head usually enters and engages the maternal pelvis in __2__ position but then rotates to __1__.

Answer 23

1) Occiput anterior

2) Occipitotransverse

Question 24

What occurs when the head fails to rotate and flex into the OA position
And may be caused by
-Cephalopelvic disproportion
-Altered pelvic architecture (Android or platypelloid)
-relaxed pelvic floor (epidural)?

Answer 24

Persistent Occipitotransverse Position

Question 25

A persistent OT position with arrest of descent for a period of 1 hr or more is called what?

Arrest occurs because of the deflexion that occurs with persistent OT positions resulting in the __2__diameter (11cm) to becomes the presenting diameter.

Answer 25

1) Transverse arrest of descent (TAD)

2) Occipitofrontal

Question 26

In management of persistent occipitotransverse position, what do you do if

• Pelvis is adequate
• Infant is not macrosomic
• Contractions are inadequate

Versus

• Inadequate Pelvis
• Macrosomic

Answer 26

1) Oxytocin and induce rotation manually or with Kielland forceps
2) Cesarean section

Question 27

Course of labor in the Occipitoposterior position is usually normal however

1) What stage is prolonged?
2) With much more discomfort where?

Answer 27

1) Second

2) Back

Question 28

How much does Macrosomia fetus weigh?

Large for gestational age is when the birth weight equals to or greater than the __2__ for a given gestational age.

Answer 28

1) 4500 g

2) 90%

Question 29

What may cause enlargement of the head that makes vaginal delivery impossible and is usually seen by ultrasound?

What P does this affect?

Answer 29

Hydrocephalus

Passenger

Question 30

__1__ or __2__ can result in a dystocia secondary to enlarged fetal abdomen.

__3__ is most common cause of this.

4) What P does this assess?

Answer 30

1) Fetal ascites
2) Enlargement of fetal organs (liver)

3) Immune hydrops (Rh isoimmunization)
4) Passenger

Question 31

1) Macrosomia can lead to damage to the nerves of the brachial plexus especially?
2) This results in what upper arm palsy?

3) What is the lower arm palsy?
4) What nerves are affected?

Answer 31

1) C5 and C6
2) Erb-Duchenne paralysis

3) Klumpke
4) C8 and T1

Question 32

What maternal risk is associated with macrosomia?

Answer 32

Postpartum hemorrhage
Significant vaginal lacerations

*Because huge head down vagina hurts mom

Question 33

____ is defined as a delivery that requires additional obstetric maneuvers following failure of gentle downward traction on the fetal head to effect delivery of the shoulders.

Answer 33

Shoulder dystocia

Question 34

Shoulder dystocia is caused by the impaction of the
-anterior fetal shoulder behind the maternal __1__
or
-the impaction of the posterior shoulder on the __2__.

__3__ can be seen with retraction of the delivered fetal head against the maternal perineum.

Answer 34

1) Pubic symphysis
2) Sacral promontory
3) Turtle sign (Head comes out then goes back in)

Question 35

Which palsy is more common?

Which is more common with shoulder dystocia?

Answer 35

1) Erb’s palsy

2) Klumpke’s palsy

Question 36

In the management of shoulder dystocia, the McRoberts Maneuver induces what movements of the maternal hips?

Answer 36

1) Hyperflexion

2) Abduction

Question 37

In the management of shoulder dystocia, __1__ pressure may dislodge the impacted anterior shoulder.

However you do NOT want to apply __2__ pressure.

Answer 37

1) Suprapubic

2) Fundal

Question 38

In the management of shoulder dystocia, when using the RUBIN MANEUVER you want to place pressure on an accessible shoulder to push it toward the ____ of the fetus to decrease the bisacromial diameter and free the impacted shoulder.

Answer 38

Anterior chest wall

Question 39

In the management of shoulder dystocia, when using the WOOD’S CORKSCREW maneuver you want to apply pressure ____ in order to rotate the infant and dislodge the anterior shoulder.

Answer 39

Behind the posterior

Question 40

1) What maneuver is for shoulder dystocia is last resort where the fetal head is manually pushed back in its original position and replaced in the vagina with steady upward pressure?
2) Delivery is then done by?

Answer 40

1) Zavanelli
2) Emergent c-section

*After baby comes out, put it back in and do C-Section

Question 41

Shoulder dystocia is an obstetric emergency, what teams should be called for help?

The initial maneuvers used are?

Answer 41

1) Anesthesiologist and NICU

2) McRoberts and suprapubic pressure