Labour and Childbirth Flashcards
When does the process of labour start?
- When the cervix starts to dilate
- ask pt. for s&s to determine onset
What are contractions?
- Intermittent tightening of the uterine muscles
- primary power needed for labour and birth
- forms regular pattern interspersed with rest periods
What changes in the last few weeks of pregnancy indicates that mother is preparing for childbirth?
- cervix softens, thins, move forwards, can begin to open
- fetus moves to the pelvis
- prodromal labour begins
What is prodromal labour?
Contractions that present as achy sensations or pressure in the lower abdomen or back during last few weeks of pregnancy
- highly variable
- regular or irregular
- mild or strong
- last for few hours to days
What’s lightening?
Fetal engagement into the maternal pelvis
- abdomen changes shape as uterus drops forward
- decreased fundal height measurement
- occurs suddenly
• 10-14 days before labour for women giving birth for the first time
• after labour has already started for women who’ve given birth before
What’s lightening?
Fetal engagement into the maternal pelvis
- abdomen changes shape as uterus drops forward
- decreased fundal height measurement
- occurs suddenly
• 10-14 days before labour for women giving birth for the first time
• after labour has already started for women who’ve given birth before
S&S of lightening
- sudden
- relieved of abdominal tightness and diaphragmatic pressure
- relief in one direction results in greater pressure below
- shooting pains down legs due to pressure on sciatic nerves
- increased vaginal discharge
- increased urinalysis frequency due to uterine pressure on bladder
Backache approaching labour
- result of postural changes
- 2/3 of pregnant women experiences low back pain
- can come from mild, early pelvic contractions
- develops from pressure on sacroiliac joint
• related to influence of relaxin hormone on pelvic joint - suggestive of labour if
• fluctuates frequently
• increases intensity
• pelvic pressure or cramping
Bloody show approaching labour
- pinkish vaginal discharge, often mixed with mucus
- results from
• dislodgement of the mucous plug that seals cervix
•rupture of cervical capillaries as engagement and dilation begins - first sign women notice
Braxton Hicks contractions
- caused by increased estrogen levels and uterine distension
- irregular
- painless
- doesn’t lead to cervical changes that indicate true labour
- when frequent and intense, it’s associated with other signs of approaching labour like low, mild backache
SROM
Natural breaking of amniotic sac (bag of waters) before or during labour
- first indication
- trickle or gush
- slightly straw-coloured amniotic fluid from vagina
- sometimes has whitish particles of vernix
- risk for umbilical prolapse
How long after SROM do women go into labour
24 hours
If not then risk of intrauterine infection
Diarrhea approaching labour
- increased bowel activity and mild diarrhea before labour
- Associated with release of prostaglandin during labour
- empty bowels so digestive system not competing for energy during childbirth
Weight loss approaching labour
Changes in estrogen and progesterone levels
• causes electrolyte shift
• decreased body fluid
Weight loss approaching labour
Changes in estrogen and progesterone levels
• causes electrolyte shift
• decreased body fluid
What is false labour?
- inaccurate
- women in prodromal or very early labour
S&S of false labour
- contractions don’t progress in frequency, intensity or duration
- no progressive cervical dilation
- prodromal labour decreases with position or activity
- fatigue and discouragement is common
What should be done during false labour?
- woman needs guidance and reassurance
- ask woman and partner to record contraction characteristics
• note contraction changes with position or activity - obtain adequate nutrition and fluids
- do not say ‘false labour’
What should be done during false labour?
- woman needs guidance and reassurance
- ask woman and partner to record contraction characteristics
• note contraction changes with position or activity - obtain adequate nutrition and fluids
- do not say ‘false labour’
S&S of true labour
- contractions increase in frequency, intensity, strength and duration
• occuring 4-6 mins, lasting 30-60 secs
• constant intervals b/w contractions - not affected by position change or activity
• can progress with walking - contractions, vaginal pressure and discomfort start at back and radiate to lower groin
- results in cervical effacement and dilation
S&S of true labour
- contractions increase in frequency, intensity, and duration
• occuring 4-6 mins, lasting 30-60 secs
• constant intervals b/w contractions - not affected by position change or activity
• can progress with walking - contractions, vaginal pressure and discomfort start at back and radiate to lower groin
- results in cervical effacement and dilation
emotional experience approaching labour
- restless or sleepless nights
- increased tension, fatigue, anxiety
- sensitive to small stimuli
- worried about ability to cope with labour
- worried about weight loss approaching labour
What is labour?
series of events that leads to expulsion of the products of conception from mother’s body
What is the traditional definition of labour?
period when regular uterine contractions are associated with cervical effacement and dilation
Issues with traditional definition of labour
- some define labour as
• time of admission to birth unit, OR
• when cervix dilates 3-4 cm, OR
• women’s self report of onset of symptoms
none of these are entirely accurate
The Ps of Labour?
Power - uterine contractions and maternal pushing
Passageway - maternal pelvis and soft parts
Passanger - fetus
What do powers consist of?
Uterine Contractions
Pushing
uterine contractions
intermittent contractions of the myometrium
throughout labour, muscles in the upper segment are ____ than the lower segment
- more active
- contracting more intensely and for longer
What are normal uterine contractions composed of?
- an increment (building up or ascending)
- an acme (the peak)
- a decrement (coming down or descending)
contraction frequency
time from beginning of one contraction to beginning of next
contraction duration
time from beginning to end of same contraction
contraction intensity
strength
why are intervals of rest important b/w contractions?
- maternal comfort
- allows for re-oxygenation of placenta to promote fetal welfare
Pushing
- provides intrabdominal force
- reserved for 2nd stage of labour, after effacement and dilation
- ‘bearing down’
- effective with controlled exhalation or holding breath briefly
Issues with pushing with a closed glottis
- called the Valsalva manoeuvre
- increases intrathoracic pressure
- impairs blood return to lower extremities
- initial increase then decrease of BP
- affects uteroplacental blood flow and perfusion
Prolonged and forceful Valsalva manoeuvre results in
- fetal hypoxia and resultant acidosis
- maternal pelvic or perineal damage
what does the passageway consist of?
- hard passage (bony pelvis)
- soft passage (maternal soft tissue structure)
what is the pelvis?
-bony ring called the hip girdle that separated lower extremity from trunk
what does the pelvis do?
- transmits body weight to lower extremities
- passageway for fetus to be born
what are the major pelvic bones?
1) innominate bones
2) sacrum
3) coccyx
what are the innonminate bones?
fusion of the ilium, ischium and pubis around the acetabulum
division of pelvis for obstretic purpose?
- into halves called false and true pelvis
what is the linea terminalis
- imaginary line that divides pelvis into true and false pelvis halves
- extends from symphysis pubis to sacral prominence
false pelvis
- wide, broad area b/w iliac crest
- supports uterus
- directs fetus to true pelvis to engage
true pelvis
- below linea terminalis
- bony birth passage
- entrance is called pelvic inlet
- shape is curved
why is the true pelvis curved?
- while descending through pelvic outlet (lower border of true pelvis), fetus moves down then up over the sacrum
- implications for positioning of women during expulsion
what are the four pelvic types?
1) gynecoid - best for vaginal birth
2) android
3) anthropoid - difficult or impossible for vaginal birth
4) platypelloid - difficult or impossible for vaginal birth
women have mixture of two types
pelvic diameter
- affects fetal ability to pass through
how to determine pelvic diameter?
measure diameter of pelvic inlet, midpelvis and pelvic outlet in the antepartal period, often on the first prenatal visit
Soft tissues that stretch to allow passage of fetus
cervix
vagina
perineum
progesterone and relaxin
- facilitate softening
- increase muscle and ligament elasticity
estrogen
- promotes growth of
• vaginal mucosa
• undderlying tissues - increases cellular glycogen
changes in the maternal soft part in the last few weeks of pregnancy
- cervix softens, effaces, more elastic
- ripening due to braxton hicks and engagement of the fetal head
- vagina
• more stretchable throughout pregnancy
• increased vascularity thickens and lengthens vaginal walls
• these changes helps passage of fetus - perineum muscles soften and more stretchable
factors that influence mechanism of labour
fetal head size and rigidity
• since head is the largest part that passes through vaginal opening
division of the fetal head
- face and base of skull - ossified and unified
- cranial vault
cranial vault bones are
- relatively thin
- poorly ossified
- loose connection to each other by membranous attachments
what is moulding
- flexibility of cranial vault allows for movement and overriding as fetal head adapts to maternal pelvis
- manifests as elongated head in newborns
- disappears few days after birth
cranial vault made up of
2 frontal bones
2 parietal bones
1 occipital bone
biparietal diameter
- distance between two parietal bones
- widest transverse diameter of fetal head
- 9.25 cm
Other fetal diameters
- suboccipitobregmatic
- submentobregmatic
- occipitofrontal
- occipitomental
sutures
- membranous attachments
• sagittal - parietal bones
• lambdoidal - parietal and occipital
• occipitomental - parietal and frontal
fontanelles
the enlarged point of intersection of sutures
what are the two major fontanelles
- diamond shaped anterior (bregma)
• won’t close until 18 months - triangular shaped posterior
•won’t close until 6-8 weeks
cranial vault is divided into
three sections
- vertex: lies b/w anterior and posterior fontanelle
- occiput: area of occipital bone
- brow: lies b/w large anterior fontanelle and eye socket
fetopelvic relationships
lie presentation presenting part attitude denominator position station
mechanisms of labour
descent flexion internal rotation extension restitution external rotation birth of shoulders and expulsion
