Normal Labour and Delivery Flashcards
what should you ask a woman when she presents to L&D
contractions
vaginal bleeding
leakage of fluid
fetal movement
what physical exam should you do on L&D
determine fetal lie (longitudinal, transverse)
determine fetal presentation (breech or cephalic)
in what % of pregnancies to membranes rupture before onset of labour
10%–> “premature rupture of membranes” (PROM)
define prolonged PROM…why do we care?
prolonged PROM is rupture 18 hours before onset of labour
greater risk of infection to both mother and fetus
what aspects of history suggest rupture of membranes
gush of, or leaking of, fluid from the vagina
how do you confirm ROM
pool, nitrazine or fern tests
what is the pool test
for ROM
collection of fluid found in the vagina on examination of the vaginal vault on sterile speculum exam
what is the nitrazine test
for ROM
vagina is normally acidic–> amniotic fluid is alkaline
when amniotic fluid comes in contact with nitrazine paper, paper turns blue
what is the fern test
for ROM
the estrogens in the amniotic fluid cause crystallization of the salts in the amniotic fluid when it dries
under low microscopic power, crystals resemble blades of a fern
DO NOT sample directly from cervix (cervical fluids also fern)
how do you confirm for sure if there was ROM if the other tests are equivocal
inject dilute indigo carmine dye into the amniotic sac to look for leakage of fluid from the cervix onto a tampon
list the 5 components of the cervical exam
dilation effacement fetal station cervical position consistency of the cervix
what is the Bishop score
determined by the 5 aspects of the cervical exam
Bishop score above 8 is consistent with a cervix favorable for both spontaneous labour and induced labour
what part of the cervix is assessed for dilation
internal os
define effacement of the cervix
subjective
how much length is left of the cervix and how thinned out it is
commonly reported by percent or by cervical length
typical cervix is 3-5 cm in length –> if cervix feels about 2 cm, then it is about 50% effaced
100% effacement occurs when cervix is as thin as the adjoining lower uterine segment
define fetal station
relation of the fetal head to the ischial spines
zero station is at the spines
define Bishop score 0 with respect to:
- cervix dilation
- cervical effacement
- station
- cervical consistency
- cervical position
- closed
- 0-30%
- -3
- firm
- posterior
define Bishop score 1 with respect to:
- cervix length
- cervical effacement
- station
- cervical consistency
- cervical position
- 1-2 cm dilated
- 40-50% effaced
- -2
- medium
- mid
define Bishop score 2 with respect to:
- cervix length
- cervical effacement
- station
- cervical consistency
- cervical position
- 3-4 cm dilated
- 60-70% effaced
- -1, 0 station
- soft
- anterior
define Bishop score 3 with respect to:
- cervix length
- cervical effacement
- station
- cervical consistency
- cervical position
- more than 5 cm dilated
- more than 80% effaced
- +1 station or more
reference point for fetal face presentations
chin
reference point for fetal breech presentations
fetal sacrum
shape of anterior fontanelle
diamond
shape of posterior fontanelle
triangle
define labour
regular contractions that cause cervical change in either effacement or dilation
define prodromal labour
“false labour”
irregular contractions that vary in duration, intensity and intervals and yield little to no cervical change
define induction of labour
attempt to begin labour in non labouring patient
define augmentation of labour
intervening to increase the already present contractions
what agents do you use to induce labour
prostaglandins
oxytocin
mechanical dilation of the cervix
and/or artificial ROM
what are the indications for induction of labour
post dates preeclampsia diabetes mellitus non reassuring fetal testing IUGR
what should you do to help prepare the cervix for induction
prostaglandins–> i.e PGE2 pessary (Cervidil) or PGE1 (misoprostol)
contraindications for the use of prostaglandins to ripen the cervix in induction
asthma or glaucoma in mom
prior cesarean delivery
non reassuring NST
what do you have to watch for when rupturing membranes with the amniotic hook
prolapse of the umbilical cord
how do you augment labour
with rupture of membranes or with oxytocin
how could you measure strength of contractions
with intrauterine pressure catheter (IUPC)
normal range for fetal HR
110-160
what does fetal tachy suggest
infection
hypoxia
anemia
what low fetal heart rate might we be worried about
decel longer than 2 min with rate below 90
describe an approach to NSTs
- baseline
- variations from baseline (variability) –> absent (less than 3 bpm), minimal (3-5), moderate (above 6) or marked (above 25)
- accelerations of at least 15 beats per min over baseline that last at least 15 seconds (2 in 20 min)
- decelerations
list the 3 types of decelerations
early
late
variable
define early deceleration and what causes it
begin and end approx same time as contractions
due to increased vagal tone secondary to head compression during contraction
define variable deceleration and what causes it
can occur at any time
tend to drop more quickly (be sharper) than early or late decels
due to umbilical cord compression
define late decelerations and what causes them
begin at the peak of a contraction and slowly return to baseline after contraction finished
due to uteroplacental insufficiency and are most worrisome
may degrade into bradys as labour progresses, especially with stronger contractions
when might you use a fetal scalp electrode
if having repeat decels or if difficult to get reading with doppler
what is the baseline intrauterine pressure
10-15 mmHg
how much does intrauterine pressure change during contractions
increase 20-30 mmHg in early labour and 40-60 mmHg in later labour