Labour and Birth Flashcards
What are the critical factors in labour?
The 5Ps
Passageway
Passenger
Position
Powers (physiological forces of labour)
Psychosocial considerations
How do we assess the passageway?
Pelvis:
Size- Inlet, mid pelvis, outlet
Shape- Gynecoid, android, anthropoid, platypelloid
Cervix
Vagina
Pelvic floor muscles
What 2 shapes are more suited for vaginal births?
Gynecoid and anthropoid
What are some components of the passenger?
Fetus head
Fetal attitude
Fetal lie
Fetal presentation
What do we assess regarding fetal head?
Bones not fused at suture lines, can overlap during labor (molding)
Fontanelles are useful in determining position of head:
Anterior is diamond shaped
Posterior is triangle shaped
What do we assess regarding attitude?
Flexion or extension of the fetal body and extremities
Normal posture is flexion commonly known as the fetal position
What is fetal lie?
Longitudinal (parallel to mother spine)
Transverse (perpendicular to mother spine)
How do we assess the presentation?
The body part of the fetus entering the pelvis in a single or multiple pregnancy
Cephalic
Breech
Shoulder
A transverse lie is associated with what kind of presentation
Shoulder presentation
When assessing the relationship of the maternal pelvis, and the presenting part of the fetal body, (position) the nurse considers what?
Engagement
Station
Fetal position
What is engagement?
Engagement occurs when the largest diameter of the presenting part reaches the pelvic inlet, typically happens about two weeks before term in a primigravida
What is the largest dimension of the fetal skull to pass through the pelvic Inlet in a cephalic presentation?
When the fetal head is flexed, the biparietal diameter is the largest dimension of the fetal skull
What is a station?
Relationship of presenting part to an imaginary line between ischial spines of the pelvis
Ranges from -5 to +5
In a normal pelvis, the ischial spines mark what?
The narrowest diameter, through which the fetus must pass. The ischial spines have been designated as zero station.
How do you measure the station of the fetal head while it is descending?
If the presenting part is higher than the ischial spines, a negative number is assigned, noting centimeters above zero station.
Station -5 is at the inlet, and station +4 is at the outlet.
What is the fetal position?
Expressed in a three part abbreviation in which the first letter refers to right or left side of maternal pelvis
The second letter is the landmark of the presenting part
The third letter tells whether the landmark is facing anterior, posterior or transverse
What are the options for the first letter in fetal position
Right or left side of maternal pelvis so R or L
For the second letter, what are the landmarks of the fetal presenting part?
Occiput (O)
Mentum (M)
Sacrum (S)
Acromion (scapula [Sc]) process (A)
How do you designate the third letter for fetal position?
Anterior (A), posterior (P), or transverse (T), depending on whether the landmark is in the front, back, or side of the pelvis
What is the most common fetal position?
Occiput anterior
What are the primary and secondary forces in labor?
The primary force is uterine muscular contractions, which cause the changes of the first stage of labor- complete effacement and dilation of the cervix
The secondary force is the use of abdominal muscles to push during the second stage of labor
What are contractions?
Involuntary rhythmic, tightening, and shortening of the uterine muscles during labor. Contractions gradually efface (thin) and dilate (open) the cervix and move baby lower in birth canal
Defined the frequency of contractions
Time from beginning of one contraction to the beginning of the next contraction
Define the duration of a contraction
Time in seconds, from beginning to the end of the individual contraction
Typically ranges from about 30 seconds to 90 seconds
What is the intensity of a contraction?
The strength of the contraction measured at its peak. When palpating, describe as mild, moderate or strong.
What is bearing down?
Voluntary pushing is begun once the cervix is fully dilated. Mother tightens her abdominal muscle during contractions to gradually eased the baby through the birth canal.
How does oxytocin or Pitocin interfere with contractions?
Increases the frequency, duration, and intensity
How does magnesium sulfate interfere with contractions?
Decreases the intensity
What are signs of impending labour?
Lightning
Braxton Hicks
Cervical changes
Bloody show
Rupture of membranes
Burst of energy
What is lightning?
When the baby drops down into the pelvis (engagement).
The uterus moves downward, and the fundus no longer presses on the diaphragm, which eases breathing
What is a bloody show?
During pregnancy, cervical secretions accumulate in the cervical canal to form a barrier called the mucous plug. With softening and effacement of the cervix, the mucous plug is often expelled, resulting in a small amount of blood lost.
Signs of true labour?
Regular contractions
Frequency, intensity, and duration increase
Discomfort often in back radiating to front
Walking makes it more uncomfortable
Rest/warm bath doesn’t ease contractions
** Progressive cervical, dilation and effacement**
Signs of false labor
Contractions are irregular with no obvious increase
Discomfort usually in abdomen
Walking may relieve discomfort
Rest/warm bath may relieve discomfort
** no cervical changes**
What is the first stage of labor?
First stage begins with onset of true labor, and ends with full dilation of the cervix. It has three phases that occur one after the other.
What is the first phase?
Latent/early phase
Mom is often talkative, excited, smiling
Contractions are usually mild
What is the second phase?
Active phase
Moms discomfort and anxiety increase as labor intensity increases
What is the third phase?
Transition phase
Mom may become restless and more anxious, labor very intense
How are the contractions during the transition phase?
They have a frequency of 1.5 to 2 minutes
A duration of 60 to 90 seconds
A strong intensity
What is the second stage of labor?
The second stage begins when the cervix is completely dilated, and ends with birth of baby
It lasts from a few mins to several hours
Mother typically feel strong urge to bear down (immediately begin pushing)
What is the third stage of labor?
Third stage follows birth of baby ends with delivery of placenta
What are the signs of placenta separation during the 3rd stage of labour?
A rounded uterus which rises in the abdomen
A sudden gush or trickle of blood
The umbilical cord protrudes further from the vagina
The fetal side looks shiny and has many blood vessels visible, and the umbilical cord at the center/the maternal side looks deep, red, and meaty
What is the fourth stage of labor?
The period of time following delivery during which mothers body adjust to sudden changes
Up to about four hours after delivery
What are some fetal responses to labor?
Heart rate changes- mild decelerations
Acid base status- blood flow to fetus decreases during peak of contractions, which leads to a gradual decrease in pH during labor
Fetal blood pressure adaptive- typically the fetus has a reserve of nutrients and gases to help it tolerate anoxic periods during contractions
What kind of psychosocial readiness can influence labor outcomes?
Hopes of what they think is going to occur during labor
Fears like the fear of the pain
How much preparation did they have? And what kind of support do they have?
How does the cardiovascular system respond to labour?
Is stressed by contractions and is also affected by anxiety or pain
How is the blood pressure and pulse rate during labor?
Pulse rate and blood pressure surge during strong contractions, which caused cardiac output to increase by about 30%
Why do we not put a laboring woman into the supine position?
This can cause her blood pressure to drop dramatically due to compression on the vena cava
How is the respiratory system during labor?
Adapt to increase demand for oxygen for both mom and baby during labor. Hyperventilation may affect the acid base balance.
How is the fluid and electrolyte balance during labor?
The work of labor causes diaphoresis (sweating) and an increased respiratory rate, both can lead to dehydration
How is the renal system during labour?
Polyuria is common during labor. Hematuria may occur as a result of trauma to the lower urinary tract.
Keep that bladder empty.
Proteinuria occurs in up to half of women during labor
What kind of liquids can women have during labor?
Clear liquids by mouth is OK for most women with uncomplicated labor and examples are:
Water, juice without pulp, sport drinks, coffee, tea, and soda
What are some physiological causes to pain during labor?
Hypoxia, pressure and stretching of muscles and tissues
