Module 2 - OB

Question 1

First stage of labour

Answer 1

onset of contractions –> full cervical dilation
early/latent = cervix dilates to 3-4 cm, baby continues to drop in pelvic inlet
active = cervix dilates to 8-9 cm
transitional = cervix dilates to 10 cm

Question 2

Second stage of labour

Answer 2

full cervical dilation –> delivery of baby
latent/passive = mother does not feel urge to push (primary powers)
active = mother actively feels urge to push (secondary powers)

Question 3

Third stage of labour

Answer 3

delivery of placenta

Question 4

Active third stage management

Answer 4

oxytocin IM usually given after delivery of anterior shoulder
gentle cord traction
promotes delivery of placenta + reduces r/o PPh

Question 5

Fourth stage of labour

Answer 5

first few hours after delivery
initiate skin-to-skin and breastfeeding
afterpains may occur d/t involution

Question 6

Precipitous labour

Question 7

Dystocia

Question 8

Pain management during labour (pharmacology)

Answer 8

nitrous oxide (laughing gas)
sterile water injection
epidural/spinal
opioids
general anesthesia
pudendal block

Question 9

Pudendal block

Answer 9

local anesthesia inserted through vagina into pudendal nerve
pudendal nerve innervates buttocks, perineum, anus/rectum/vulva
DOES NOT take away pain of contractions

Question 10

Sterile water injection

Answer 10

inserted intradermally/subcutaneously in lower back
works via gate control theory

Question 11

Nitrous oxide

Answer 11

controlled by mom
can be used for 2-3 hours max
minimal adverse effects
may blunt pain but not remove it

Question 12

Opioids

Answer 12

fentanyl/morphine
cause feelings of euphoria/anagelsia
if given too close to delivery can lead to respiratory depression in newborn

Question 13

Epidural/spinal

Answer 13

local anesthesia inserted into epidural space/subarachnoid space
can be used throughout labour
has many adverse fx: dural headache, urinary retention, hypotension, motor block
can affect baby’s ability to breastfeed

Question 14

General anesthesia

Answer 14

total sedation + anagelsia + amnesiac fx
mom is totally out –> misses pregnancy
may have adverse fx on baby (BF ability)

Question 15

First stage labour pain

Answer 15

visceral pain
pain felt during contractions
felt in lower back, abdomen, sides

Question 16

Second stage labour pain

Answer 16

pain increases as contractions become longer and more frequent
pain begins to be felt near perineum

Question 17

Episiotomy

Answer 17

surgical incision made into perineum to facilitate delivery

Question 18

4 T’s of PPH

Answer 18

Tone
Trauma
Tissue
Thrombin

Question 19

Tone RF

Answer 19

overdistended uterus
polyhydramnios
multiple gestation
macrosomia
uterine muscle exhaustion (precipitous labour, prolonged labour, high parity, oxytocin induction)
intra-amniotic infection (fever, prolonged ROM)
placenta abnormalities (previa, fibroid)
uterine-relaxing medication (halogenated anesthesia, nitroglycerin)
distended bladder

Question 20

How does oxytocin lead to uterine atony?

Answer 20

causes desensitization to oxytocin –> decreased contractions

Question 21

Trauma RF

Answer 21

laceration (precipitous delivery, assisted delivery)
C/S
uterine rupture
uterine inversion

Question 22

Tissue RF

Answer 22

retained products - abnormal placentation (accreta, increta, percreta, extra lobe, incomplete delivery)
previous uterine surgery
high parity
abnormal placenta on ultrasound
retained blood clots
atonic uterus

Question 23

Thrombin

Answer 23

pre-existing blood disorders (hemophilia A, vWD dx, idiopathic thrombocytopenia)
history of liver dx
DIC

Question 24

Which layer of the uterus contracts to prevent blood loss?

Answer 24

myometrium contracts after birth
this squeezes maternal blood vessels supplying the spiral arteries of the endometrium

Question 25

Uterotonic drugs

Answer 25

oxytocin
misoprostol
methylergonovine
carboprost
tranaxemic acid

Question 26

Oxytocin

Answer 26

exogenous hormone
causes uterine contraction
given IM/IV

Question 27

Misoprostol

Answer 27

prostaglandin causing uterine contractions + antiulcer effects
CI in allergy
given rectal, SL, PO

Question 28

Methylergonovine

Answer 28

ergot alkaloid
stimulates uterine/vascular smooth muscle contraction
CI in HTN, pre-eclampsia, cardiac disease
givne IM, IU, PO

Question 29

Carboprost

Answer 29

prostaglandin
causes uterine contractions by stimulating myometrium
CI: asthma, HTN
given IM, IU

Question 30

Tranaxemic acid

Answer 30

plasminogen inactivator
prevents fibrinolysis
CI: hx of blood clots, concurrent anticoagulant use
given iV

Question 31

PPH interventions

Answer 31

fundal massage
O2 therapy (simple face mask)
lower HOB
IV access –> blood products, uterotonic drugs (oxytocin), fluid bolus
I&O/indwelling catheter
monitor labs

Question 32

5 factors affecting labour

Answer 32

Passenger (fetus/placenta)
Pathway (birth canal)
Psychological
Powers (primary and secondary)
Position (of mother)

Question 33

Passenger factors

Answer 33

size of fetal head
fetal presentation (cephalic, breech - which part of the body facing opening)
fetal lie (longitudinal, transverse, horizontal, oblique)
fetal attitude (flexion)
fetal position (reference point of presenting part to pelvis)

Question 34

Types of pelvises

Answer 34

gynecoid (normal)
android (masculine)
anthropoid (resembling apes)
platypelloid (oval)

Question 35

Primary powers

Answer 35

involuntary contractions

Question 36

Secondary powers

Answer 36

pushing of the mother

Question 37

Birth position

Question 38

Station

Answer 38

relationship of presenting fetal part to imaginary line drawn b/w maternal ischial spines
measures how far into pelvic inlet baby has dropped

Question 39

Contraction characteristics

Answer 39

frequency
duration
intensity

Question 40

Effacement

Answer 40

shortening/thinning of cervix

Question 41

Dilation

Answer 41

enlargement/widening of cervix

Question 42

Lightening

Answer 42

feeling of baby as it drops into true pelvis

Question 43

Show

Answer 43

vaginal/cervical mucus increases during fetal descent
may be bloody/rust-colored

Question 44

Cervical ripening

Answer 44

cervix becomes soft