Labour and Birth Processes

Question 1

Factors Affecting Labour: 5 P’s

Answer 1

Passenger
Passageway
Powers
Position of laboring woman
Psychologic state of laboring woman

Question 2

Passenger: Size of the fetal head

Answer 2

• bones in the fetal skull
• fontanels
• molding

Question 3

Passenger: presentation of the fetus

Answer 3

the part of the fetus that enters the pelvic inlet first and leads through the birth canal during labor
- cephalic (head)
- breech
- shoulder

Question 4

Passenger: Fetal lie

Answer 4

the relaxation of the long axis (spine) of the fetus to the long axis (spine) of the mother
- longitudinal
- vertical

Question 5

Passenger: Fetal attitude

Answer 5

the relation of the fetal body parts to one another
- general flexion
- critical measurements of fetal head
Biparietal diameter
Suboccipitobregmatic diameter

Question 6

Biparietal diameter

Answer 6

smallest, 9.25 cm
vertex presentation
one side of the parietal bone to the other

Question 7

Suboccipitobregmatic diatmeter

Answer 7

anterior fontanel to bottom of occiput
9.5 cm

Question 8

Passenger: Fetal Position

Answer 8

the relationship of a reference point on the presenting part to the four quadrants of the mother’s pelvis
- position is denoted by a three-part letter abbreviation (ex. ROA, LSP)

Question 9

Passenger: Fetal Station

Answer 9

a measure of the degree of descent of the presenting part of the fetus through the birth canal

Question 10

Passenger: Fetal engagement

Answer 10

usually corresponds to 0 station

Question 11

Passageway:

Answer 11

Birth Canal:
- Body pelvis: 4 types
Gynecoid
Android
Anthropoid
Platypelloid
- Soft tissues

Question 12

Powers: primary

Answer 12

Primary powers: contractions
- frequency (beginning of one contraction to the beginning of the next), duration (how long), intensity (at peak of contraction)

Question 13

Effacement

Answer 13

The shortening and thinning of the cervix during the first stage of labor. Effacement generally progresses significantly in first-time term pregnancy before more than slight dilation occurs. In subsequent pregnancies, effacement and dilation of the cervix tend to progress together. Degree of effacement is expressed in percentages from 0% to 100%

Question 14

Dilation

Answer 14

The enlargement or widening of the cervical opening and the cervical canal that occurs once labor has begun. The diameter of the cervix increases from being close to full dilation to allow birth of a term fetus

Question 15

Ferguson Reflex

Answer 15

: increased intrauterine pressure that puts the pressure on the descending part of the fetus against the cervix. Muscles contracting and pulling the cervix up and the pushing of the baby. And then mom bearing down to help. Ferguson reflex makes mom feel like she needs to push. Might feel like this at 7-8 cm but she has to wait until filly dilated

Question 16

Secondary Powers

Answer 16

Bearing-down efforts
- Valsalva maneuver

Question 17

Process of Labour: Labor

Answer 17

process of moving fetus, placenta, and membranes out of the uterus and through the birth canal

Question 18

process of labour: signs preceding labor

Answer 18

Lightening - sensation of decreased abdominal distention produced by uterine descent into the pelvic cavity as the fetal presenting part settles into the pelvis; it usually occurs 2 weeks before the onset of labour. as head settles into the pelvis the woman can sense greater room - sense of easier respirations.
Blood show - vaginal discharge that originates in the cervix and consists of blood and mucus; increases as cervix dilates during labour. associated wth thinning cervix. (mucus plug)
- Baby is descending into the true pelvis
- Frequency of urine (because the baby is pushing on the bladder)
- Uterus grows overtop of the bladder (anteflexion) beginning of pregnancy, frequency of urine. Later the uterus grows up and the bladder is fine until the lightening
- Test urine every visit
- She can lie down again to sleep because she feels she is getting more oxygen again
- Everything is getting ready for the birth. Ligaments are softening and becoming looser (back pain, imbalance)
- Everything is getting ready! Braxton Hicks are irregular contractions
- Mother might be losing some weight
- Nesting (a lot of energy, all aspects working together) mom is going to need that energy
- Flu-like symptoms close to birth.

Question 19

Psychological State of Woman

Answer 19

What is happening with mom and the family. Culture, situation that resulted in the baby, might be all by herself, extreme rural area, age, adolescent pregnancy, language barriers. Emotional and psychological state of labouring woman impacts the labour significantly

Question 20

Onset of Labour

Answer 20

• Cannot be ascribed to a single cause
• • Progesterone is falling
• Oxytocin is increasing
• Prostaglandins
• All working together for strong rhythmic uterine contractions
• All of these things are working together

Question 21

Stages of Labour

Answer 21

First Stage:
Latent phase (slow descent and slow dilation)
Active phase (when there is dilation of the cervix)
Transition phase
Second Stage
Third Stage
Fourth Stage

Question 22

Turns and adjustments necessary in human birth process: Seven cardinal movements of mechanism of labor

Answer 22

1. Engagement
2. Descent
3. Flexion
4. Internal rotation
5. Extension
6. Restitution and external rotation
7. Expulsion

Question 23

Physiologic Adaptation to Labor: Fetal adaptation

Answer 23

• Fetal heart rate: reliable and predictive information about the condition of the fetus related to oxygen
• Fetal circulation
• Fetal respiration

Question 24

Physiologic Adaptation to Labor: Maternal adaptation

Answer 24

Women exhibits both objective and subjective symptoms
- cardiovascular changes
- respiratory changes
- renal changes
- integumentary changes
- musculoskeletal changes
- neurologic changes
- gastrointestinal changes
- endocrine changes

Question 25

Key Points

Answer 25

• Labour and birth are affected by the five Ps: passenger, passageway, powers, position of the woman, and psychologic response
• because of its size and relative rigidity, the fetal head is a major factor in determining the course of birth
• the diameters at the plane of the pelvic inlet, the midpelvis, and the outlet plus the axis of the birth canal determine whether vaginal birth is possible and the manner in which the fetus passes down the birth canal
• Involuntary uterine contractions act to expel the fetus and placenta during the first stage of labor; these are augmented by voluntary bearing-down efforts during the second stage

Question 26

Stages of labor key points

Answer 26

• The first stage of labor lasts from the time dilation begins to the time when the cervix is fully dilated
• the second stage of labor lasts from the time of full cervical dilation to the birth of the infant
• third stage of labor lasts from the infants birth to the expulsion of the placenta
• the fourth stage of labor begins with the delivery of the placenta and includes at least the first 2 hours after birth

Question 27

Cardinal movements key points

Answer 27

• the cardinal movements of the mechanism of labor are engagement, descent, flexion, internal rotation, extension, restitution and external rotation, and explusion of the infant
• although the events precipitating the onset of labor are unknown, many factors, including changes in the maternal uterus, cervix, and pituitary gland, are thought to be involved
• a healthy fetus with an adequate uterofetolacental circulation is able to compensate for the stress of uterine contractions
• as the woman progresses through labor, various body systems adapt to the birth process