B8.017 The Labor Process at Term: Normal Labor and Potential Complications

Question 1

general facts about term in pregnancy

Answer 1

38-42 weeks of pregnancy
weeks of pregnancy are dates from the 1st day of the patient’s LMP
normal pregnancy lasts 40 weeks

Question 2

how many pregnancies end in normal labor and delivery

Answer 2

over 2/3

Question 3

stages of labor

Answer 3

1st stage: cervical
2nd stage: expulsion
3rd stage: placental

Question 4

describe the events of the cervical stage of labor

Answer 4

begins with the onset of labor
ends when the cervix is fully dilated
follows a characteristic course in a normal labor
gets shorter with subsequent pregnancies

Question 5

acceleration phase of cervical dilation

Answer 5

4-5 cm range

cervix is thinned and progresses more quickly through active phase

Question 6

events of the expulsion stage

Answer 6

begins at full cervical dilatation
ends with delivery of the baby
aided by use of abdominal muscles in a valsalva-like maneuver to bring pressure to bear on the uterine fundus
“pushing” can double the expulsive force

Question 7

events of the placental stage

Answer 7

begins with the delivery of the baby
ends with delivery of the placenta
relies on involution of the uterus through continued contractions to affect separation of the placenta

Question 8

signs of placental separation

Answer 8

increased bleeding per vagina in the majority of cases
lengthening of the umbilical cord
change in uterine shape to a globular configuration
cephalad displacement of the uterus as the placenta descends in the birth canal

Question 9

possible outcomes with placental delivery

Answer 9

1. successful delivery of the placenta
2. avulsion of the umbilical cord
3. inversion of the uterus

Question 10

result of uterus inversion with placenta delivery

Answer 10

pronounced vagal response

patient hemorrhages and rather than HR increasing, it drops

Question 11

cardinal movements of labor from the fetal aspect

Answer 11

1. engagement
2. descent
3. flexion
4. internal rotation
5. extension
6. external rotation
7. expulsion

Question 12

engagement

Answer 12

presenting part (head) has reached the ischial spines on vaginal exam

Question 13

internal rotation

Answer 13

face turns toward sacrum

Question 14

flexion

Answer 14

chin to chest

Question 15

extension

Answer 15

head begins to push through cervix

neck extended against pubic symphisis

Question 16

external rotation

Answer 16

face sideways again after coming out of vaginal canal

Question 17

labor complications

Answer 17

dystocia
emergencies:
-cord prolapse
-shoulder dystocia

Question 18

dystocia

Answer 18

difficult labor or childbirth

Question 19

protracted labor/descent

Answer 19

slow labor

Question 20

arrested labor/descent

Answer 20

stopped labor

Question 21

protracted labor

Answer 21

<1.2 cm/h nulligravida
<1.5 cm/h
multipara

Question 22

protracted descent

Answer 22

<1.0 cm/h nulligravida
<2.0 cm/h
multipara

Question 23

arrested labor

Answer 23

> 2 hr

Question 24

arrested descent

Answer 24

> 1 hr

Question 25

causes for dystocia

Answer 25

the 3 p's power passenger passage

Question 26

passage

Answer 26

birth canal = true pelvis

Question 27

issues assessed with clinical pelvimetry

Answer 27

pelvic inlet sacral contour bony prominences pelvic outlet

Question 28

gynecoid pelvis

Answer 28

predominant female pelvis shape

Question 29

anthropoid pelvis

Answer 29

long A/P

Question 30

android pelvis

Answer 30

predominant male pelvis shape | heart shape

Question 31

platypelloid pelvis

Answer 31

short A/P | long in lateral direction

Question 32

frequency of pelvic types

Answer 32

gynecoid > android > anthropoid > platypelloid

Question 33

complications with android pelvis

Answer 33

head wedged in descent stops due to narrowing of canal arrest of descent

Question 34

complications with anthropoid pelvis

Answer 34

cant extend head all the way | persistent occiput posterior

Question 35

complications with platypelloid pelvis

Answer 35

head stuck in transverse position

Question 36

episiotomy

Answer 36

enlarges the vaginal outlet to facilitate delivery | prophylactic episiotomy controversial and has lost favor

Question 37

types of episiotomy

Answer 37

midline | mediolateral

Question 38

advantages of midline episiotomy

Answer 38

less pain ease of repair less blood loss

Question 39

disadvantages of episiotomy

Answer 39

greater risk of extension into anal spinchter and/or rectum

Question 40

umbilical cord prolapse

Answer 40

when the umbilical cord descends in advance of the presenting fetal part

Question 41

funic umbilical cord

Answer 41

4% | when the membranes are intact, and the cord can be felt in the bag of waters

Question 42

occult prolapse

Answer 42

11% | when the cord is lying beside the presenting part

Question 43

overt prolapse

Answer 43

45% cord protruding through the cervix into the vagina | 39% cord escaping from vagina

Question 44

risk factors for cord prolapse

Answer 44

``` low birth weight preterm birth breech presentation multiple gestation malpresentation hydramnios obstetrical interventions ```

Question 45

cord prolapse mortality

Answer 45

stable mortality rate: 36-162 per 1,000 cases | most deaths result from complications of prematurity rather than poor recognition or inadequate treatment

Question 46

cord prolapse management

Answer 46

recognize call for help relieve remove

Question 47

recognition of cord prolapse

Answer 47

care provider should elevate the presenting part to prevent compression of the cord

Question 48

relief of cord prolapse

Answer 48

place patient in trendelenburg position of knee-chest position manual elevation of the presenting part of the fetus above the pelvic inlet monitor the fetus as the maneuvers are carried out

Question 49

removal of cord prolapse

Answer 49

if cervix is fully dilated, and there is no evidence of fetal distress, consider assisted vaginal delivery if not fully dilated, emergency C section

Question 50

shoulder dystocia

Answer 50

after delivery of the fetal head, further expulsion of the infant is prevented by impaction of the fetal shoulders within the maternal pelvis

Question 51

epidemiology of shoulder dystocia

Answer 51

0.15-1.7% of all vaginal deliveries severe asphyxia in 143 per 1,000 births with shoulder dystocia compared with 14 per 1,000 overall mortality = 21-290 in 1,000

Question 52

risk factors for shoulder dystocia

Answer 52

``` fetal macrosomia materal diabetes maternal obesity post term gestation prior history of either macrosomia or shoulder dystocia operative vaginal delivery ```

Question 53

clinical findings that suggest possible shoulder dystocia

Answer 53

prolonged 1st stage of labor, especially the decelerative phase protracted 2nd stage fetal head draws back after delivery, with the chin tight to perineum

Question 54

maneuvers to alleviate a shoulder dystocia

Answer 54

``` knees to chest suprapubic pressure (not fundal pressure tho) deliver the posterior arm corkscrew maneuvers fracture the fetal clavicle ```

Question 55

maternal complications of shoulder dystocia

Answer 55

11% rate of postpartum hemorrhage | 3.8% rate of fourth degree lacerations

Question 56

neonatal complications of shoulder dystocia

Answer 56

fractures- clavicle and/or humerus | brachial plexus injuries- reported anywhere from 4-40% of deliveries complicated by shoulder dystocia