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

During labor, two distinct segments of the uterus are formed, the __1__ segment which actively contracts and retracts to expel the fetus and the __2__ segment along with the cervix becomes thinner & passive.

Answer 3

1) Upper

2) Lower

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__, increase in __2__, decrease in __3__, which favors increased water content.

Answer 5

1) Collagenolysis
2) Hyaluronic acid
3) Dermatan sulfate

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

Normal limits of the latent phase in a nulliparous mother can reach up to __1__ hours.

In a multiparous mother it can reach up to __2__ hours.

Answer 9

1) 20 hours

2) 14 hours

Question 10

Latent phase that exceed the norms is considered prolonged but the outcome of prolonged latent phase has little effect on perinatal mortality. What are some causes of prolonged latent phase?

Answer 10

1) Excessive use of sedatives

2) Fetal malposition

Question 11

What normal daily function is recommended with prolonged latent phase as it can provide patient with relief and aid in distinction between true and false labor?

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

Normal limits of the active phase in nulliparous mothers for cervical dilation is __1__?

Normal limits of the active phase in multiparous mothers for cervical dilation is __2__?

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

Normal limits of the active phase in nulliparous mothers for fetal descent is __1__?

Normal limits of the active phase in multiparous mothers for fetal descent is __2__?

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

____ is defined “difficult labor” it can be used interchangeably with dysfunctional labor characterizing that labor is not progressing normally.

Answer 14

Dystocia

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 contractions are less then __2__ in 10 minute period and/or the intensity is less than __3__ mm/Hg.

Answer 16

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

Question 17

ACOG recommends ____ in protraction and arrest disorders after assessing maternal pelvis, fetal position, station, and 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.

It require membrane to be __2__.

Answer 18

1) Intensity

2) Ruptured

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

Montevideo Units are calculated by measuring the __1__ in mmHg in a 10 min period.

It should be greater than __2__ for at least two hours.

Answer 20

1) Peaks of contractions

2) 200

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__ refers to a disparity between the size of the maternal pelvis & the fetal head that precludes vaginal delivery.

It causes a failure of __2__.

__3__ women who present in labor with an unengaged head indicates an increased likelihood.

Answer 22

1) Cephalopelvic disproportion
2) Descent
3) Nulliparous

Question 23

____ and ____ shaped pelvises have a good prognosis for delivery.

Answer 23

Gynecoid and Anthropoid

Question 24

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 24

1) Occiput anterior

2) Occipitotransverse

Question 25

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 pelvis), or relaxed pelvic floor (epidural)?

Answer 25

Persistent Occipitotransverse Position

Question 26

A persistent OT position with arrest of descent for a period of 1 hr or more is known as __1__.

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

Answer 26

1) Transverse arrest of descent

2) Occipitofrontal

Question 27

If pelvis is adequate, infant is not macrosomic, and contractions are inadequate what is the management for the Persistent Occipitotransverse Position?

If pelvis is inadequate or infant deemed to be macrosomic proceed with?

Answer 27

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

Question 28

Course of labor in the Occipitoposterior position is usually normal however the __1__ stage may be prolonged and it may be associated with considerably more __2__ discomfort.

Answer 28

1) Second

2) Back

Question 29

Macrosomia is defined as the fetus weighing __1__?

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

Answer 29

1) 4500 g

2) 90%

Question 30

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

Answer 30

Hydrocephalus

Question 31

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

__3__ is most common cause of this.

Answer 31

1) Fetal ascites
2) Enlargement of fetal organs (liver)
3) Immune hydrops (Rh isoimmunization)

Question 32

Macrosomia can lead to damage to the nerves of the brachial plexus especially?

This results in what upper arm palsy?

Answer 32

1) C5 and C6

2) Erb-Duchenne paralysis

Question 33

Klumpke paralysis is a lower arm palsy caused by damage to?

Answer 33

C8 and 1st thoracic nerve

Question 34

What maternal risks are caused by macrosomia?

Answer 34

Postpartum hemorrhage and significant vaginal lacerations

Question 35

____ 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 35

Shoulder dystocia

Question 36

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 which is retraction of the delivered fetal head against the maternal perineum.

Answer 36

1) Pubic symphysis
2) Sacral promontory
3) Turtle sign

Question 37

Which palsy is more common?

Which is more common with shoulder dystocia?

Answer 37

1) Erb’s palsy

2) Klumpke’s palsy

Question 38

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

Answer 38

1) Hyperflexion

2) Abduction

Question 39

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

However you do NOT want to apply __2__ pressure.

Answer 39

1) Suprapubic

2) Fundal

Question 40

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 40

Anterior chest wall

Question 41

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 41

Behind the posterior

Question 42

__1__ maneuver for shoulder dystocia is the last resort maneuver where the fetal head is manually returned to its prerestitution position and slowly replaced in the vagina by steady upward pressure.

Delivery is then done by?

Answer 42

1) Zavanelli

2) Emergent cesarean section

Question 43

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

The initial maneuvers used are?

Answer 43

1) Anesthesiologist and NICU

2) McRoberts and suprpubic pressure