14. Dysfunctional Labor

Question 1

Uterus is smooth muscle organ, cells contract when increased calcium concentration resulting in actin myosin contraction, stimulation of oxytocin receptors on plasma membrane activate the actin/myosin complex, contractions occur in localized areas during gestation, but during labor the entire uterus contracts in an ?

Answer 1

organized fashion

Question 2

Relaxation is maintained by factors that increase cyclic adenosine monophosphate (cAMP), contraction increase intracellular calcium stores and promote interaction of actin and myosin which causes?

Answer 2

contractions

Question 3

During labor uterus has upper segment which contracts and retracts to expel fetus and lower segment + cervix becomes thinner and passive, cervix contains collagen and SM, changes from firm intact sphincter to soft, pliable dilatable structure, due to increase in hyaulronic acid, decrease in dermatan sulfate and ?

Answer 3

collagenolysis

Question 4

First stage of labor has latent phase which cervical softening and effacement occurs with MINIMAL dilation (less than 4cm). Active phase starts when cervix is dilated to? - phase includes increased rate of dilation and descent of presenting fetal part w acceleration and deceleration phase

Answer 4

**6CM

Primiparous: dilate at 1.2cm/hr
(multiparous: dilate at 1.5cm/hr)

Question 5

For all phases of labor, abnormality is either protraction (slower than normal rate) and arrest = complete cessation of progress (no further dilation/descent), arrested latenet phase implies labor has not begun, what type of labor is when rates of dilation and descent exceed times of normal labor pattern?

Answer 5

Dysfunctional labor

Question 6

Normal limits of latent phase for primi is 20hours and multi is 14hours, latent phase exceeding norms is considered prolonged, MC is caused by patients who entered labor without no cervical change, excessive use of sedative or analgesic and fetal?

Answer 6

malposition

Question 7

Managment of prolonged latent phase is therapeutic rest and morphine with most patients progressing to?

Answer 7

Active phase (some will have false labor and some will need pitocin)

Question 8

Cervical dilation less than normal / hour cm is protraction* disorder of dlation of active phase and if 2+ hours elapse with NO cervical dilation a what of dilation has occured?

Answer 8

Arrest of dilation

Question 9

Normal decent in prim is 1cm/hr and multi is 2cm/hr, fetal descent less than norms is protaction disorder of descent and if no descent has occured then arrest of descent has occured. Anormalities of active phase (unlike latent phase) can increase risk of ?

Answer 9

perinatal mortality

Etiology is inadequate uterine activity, cephalopelvic disproportion, fetal malposition and anesthesia

Question 10

Dystocia is defined as difficult labor or not progressing normally, results from three P’s = power, passenger and passage, dx of dystocia should NOT be made before an adequate trial of?

Answer 10

labor has been tried
Power: uterine contractions/expulsive forces
Passenger: position, size, presentation
Passage: maternal pelvic bone structures

Question 11

COnsider augmentation if contractions are less than 3 in 10minutes or intensity is less than 25mmHg (ACTIVE phase), reccomend which drug in protraction and arrest after assessing maternal pelvis, fetal position, station and maternal and ffetal status?

Answer 11

Oxytocin/Pitocin

Question 12

Assesing 3 P’s of abnormalities of the active phase… POWER: IUPC- catherter places giving precise measurement of intensity of contractions, requires membranes to be rupture- artificial rupture of membranes has benefits including augment labor and allows assessment of meconium while has risks of what, along with prolonged rupture - chorioamnionitis?

Answer 12

Cord Prolapse

Question 13

Minimal effective uterin activity is 3 contraction in 10 mins averaging 25mmHg above baseline, usually MVU should be greater than 200 for 2 hours (calculated measure peaks of contractions in a 10 min period), if there are inadequate urterine contractions, what should be started?

Answer 13

PITOCIN (only FDA approved)

increases calcium, 20-30 mins until effect, 80% respond and give birth

Question 14

Assessing passage includes cephalopelvic disproportion CPD- size of head and pelvis dont match, causing failure of descent- nulliparous women who present in labor with unengaged head indicated increased likelihood of?

Answer 14

CPD

Question 15

What pelvis have good prognosis for deliver, pubic arch >90, ischial tuberosity >8,5cm, diagnoal conjugate >11cm, and prominence of ischial spines?

Answer 15

Gynecoid and Anthropoid pelvis’

Question 16

Assessing PASSENGER: presentations other than vertex occiput anterior (OA) are considered abnormal, fetal head usually engages pelvis as OT and then rotates to OA, can persist in OT or rotate to OP,dystocia may also be caused by fetal abnls including fetal anomalies, shoulder dystocia and**?

Answer 16

macrsomia

Question 17

Persistent occiputtransverse OT, occurs when head does not rotate and flex in OA, may be caused by CPD, with arrest of descent for a period of 1hr+ is a transverse arrest of descent- arrest occuring due to de-?

Answer 17

deflexion that occurs with persistent OT (occipitofrontal diameter 11cm is presenting)

Question 18

Management of OT presentation if pelvis is adequate, start oxytocin, rotation manually or with KEILLAND forceps, is pelvis is inadequate or macrosomia then C-section. What forceps?

Answer 18

Keilland forceps to rotate OT to OA

Question 19

Persistent OP position in assessing passenger… head usually rotates OT to OA, if in OP will eventually SPONTANEOUSLY rotate during labor to OA, course of labor is usually normal, 2nd stage may be prolonged but there is considerably more maternal?

Answer 19

back pain

Question 20

Macrosomia is when fetus weights >4500g, accounts for 1.5% births, large for gestational age LGA - birth rate greater than 90%, diagnosis with US is imprecise. What may cause enlargment of the ehad that makes vaginal delivery impossible-seen on US?

Answer 20

Hydrocephalus

Question 21

Fetal ascites or enlargement of fetal organs (liver) can result in dystocia secondary to enlarged abdomen, most commonly due to what, along with congenital infections, chr abnormalities and fetal arryhthmias?

Answer 21

Immune Hydrops = Rh isoimmunization** MC

Question 22

After checking 3 P’; power, passage, and passenger during the active phase of labor, you may proceed with?

Answer 22

C section

Question 23

Risks for macrosomia include maternal DM, previous hx, pre preg obesity, weight gain during preg, multparity, male fetus, gestation age >40, ethnicity, maternal birth weigth/height/age <17, positive 1hr glucose but negative 3 hour glucose intolerance……

Answer 23

MEOW

Question 24

Macrosomia is associated with shoulder dystocia, fracture of clavicle, damage to nervous of brachial plexus, which usually resolve- but causes increase change by 21x. What plexus injury causes upper arm palsy, MC** brachial plexus injury and caused by injury to 5/6th cranial nerves?

Answer 24

Erb-Duschenne (waiter tip)

Question 25

Klumpke brachial plexus injury is lower arm palsy caused by damage to the C8 and T1 nerves (painful), and paralysis of the entire arm may occur due to damage of ?

Answer 25

all four nerve roots (c5-t1?)

Question 26

macrosomia causes increased risk of morbidity for infants and mothers, so ACOG suggest prophylactic csection delivery for an estimated fetal weight of 5000gms in nondiabetic patients and what in diabetic patients?

Answer 26

> 4500gms in diabetic patients (due to increased chance of shoulder dystocia)

Question 27

Shoulder dystocia is a delivery that requires additional obstetric maneuvers following failure of gentle downward traction on fetal head, caused by impaction of anterior fetal should behind pubic symphysis or post shoulder on sacral promontory- what sign is retraction of delivered fetal head against the maternal perineum?

Answer 27

turtle Sign

Question 28

Shoulder dystocia ban cause brachial plexus injuries (10% of all result in permanent damage), fracture clavicle, hypoxic-ischemic encephalopathy and death of the neonate. Managmenet include suprapubic pressure which may dislodge the impacted anterior shoulder (NO* fundal pressure) along with what maneuver which is HYPERflexion and abduction of the maternal hips?

Answer 28

McRobert’s Maneuver

can also do proctoepisiotomy

*Zavanelli Maneuver: cephalic replacement, last resort, cardinal moves in reverse

Question 29

What manuever: place pressure on accessible shoulder to push it forward toward the anterior chest wall of the fetus to decreases the bisacrominal diamtere and free the impacted shoulder?

Answer 29

Rubin Maneuver

Question 30

What manuever do you apply pressure behind the posterior to rotate the infant and dislodge the anterior shoulder?

Answer 30

Woods Corkscrew

Question 31

What maneuver is laster resort for shoulder dystocia, (after doing mcroberts, rubin/woods) and is when the fetal head is manually returned to its prerestitution postion, slowly placed in the vagina by steady upward pressure (poor prognosis), delivery is by EMERGENT C section?

Answer 31

Zavanelli

***most shoulder dystocia occur in absence of macrosomia