NURS 3358 - OB Exam 1 Study Guide.
LABOR AND BIRTH PROCESSES / NURSING CARE
DURING LABOR & BIRTH
OBJECTIVES
• Describe the process of labor and the major factors affecting it and the associated nursing interventions that enhance
labor progress.
• Describe maternal and fetal adaptations to labor.
• Develop a plan of care that enhances labor progress for labor and birth.
• Review the factors included in the initial assessment of the woman in labor.
• Describe the ongoing assessment of maternal progress during the first, second, and third stages of labor with and without
risk factors identified.
• Recognize the physical and psychosocial findings indicative of maternal progress during labor.
• Describe the influence of cultural and religious beliefs and practices on the process of labor and birth.
• Discuss ways the nurse can use evidence-based practices to enhance the quality of care a woman receives during labor
and birth.
Quick Overview of Anatomy:
• Baby sits inside pelvis
Factors Affecting Labor
• The 5 P’s of Labor: Passenger, Passageway, Powers, Position of laboring woman, Physiologic response (maternal)
o Passenger: fetus and placenta
▪ Size of fetal head – fontanels allow for some movement; the baby’s head can mold to fit the mother’s pelvis; if
the baby’s head is bigger than the mom’s pelvis = cephalopelvis disproportion
▪ Fetal presentation
▪ Fetal Lie – relation of the long axis (spine) of the fetus to the long axis of the mother; longitudinal (baby’s spine
is longitudinal to mother’s spine)
▪ Attitude – the relation of the fetal body parts to one another; vertex with full flexion or general flexion ; military
▪ Position – relationship of the presenting part to the four quadrants of the mother’s pelvis
➢ First letter – tells us the location of the presenting part, in either the right or the left side of the pelvis
➢ Second letter – presenting part of the fetus
➢ Third letter – location of the presenting part to the anterior, posterior, or transverse portion of the pelvis
o Passageway: birth canal
▪ Bony pelvis
▪ Soft tissues – lower uterine segment – retraction ring
▪ Cervix, pelvic floor, vagina, introitus
Presentation – Part of the fetus that enters the pelvic inlet first
• Cephalic – head first
o Vertex – general flexion and the occiput is the general presenting part
o Face
o External cephalic version – version of the fetus from breech to vertex presentation; 36/37 weeks is ideal for
performing this
• Breech – buttock, foot, or feet
o Frank Breech
▪ Lie – Longitudinal or vertical
▪ Presentation – breech (incomplete)
▪ Presenting Part – sacrum
▪ Attitude – flexion, except for legs at knees
o Single Footling Breech
▪ Lie – Longitudinal or vertical
▪ Presentation – breech (incomplete)
▪ Presenting part – sacrum
▪ Attitude – flexion, except for one leg at hip and knee
o Complete Breech
,NURS 3358 - OB Exam 1 Study Guide.
▪ Lie – longitudinal or vertical
▪ Presentation – breech (sacrum and feet presenting)
▪ Presenting part – sacrum with feet
▪ Attitude – general flexion
• Shoulder
o Lie – transverse or horizontal
o Presentation – shoulder
o Presenting part – scapula (Sc)
o Attitude – Flexion
Presenting Part – part of fetus that lies closest to internal os
• Occiput or Mentum – hyperextended, mentum = chin
• Sacrum
• Scapula
Fetal Station – Engagement
• How close the presenting part is to the ischial spine
• If it is equal with the ischial spine 0 spine
• Negative – baby is higher up in the pelvis
• Positive – baby is further down into the pelvis
The 5 P’s of Labor – Powers:
• Primary powers – uterine contractions Frequency, duration and intensity
• Secondary powers – maternal bearing-down efforts - “Push!
Primary Powers – Contractions
• The shortening of a muscle in response to a stimulus with return to its original length
o Increment – building up; longest phase of contraction
o Acme – peak
o Decrement – letting up
o Assess for frequency, duration and intensity
• Uterine Tonus: the degree of pressure exerted by the uterine musculature as measured by intrauterine pressure
• Measured by mmHg
• Normal baseline tonus between contractions 8-12 mm Hg
• Pressure at peak of contraction ranges between 35-75 mmHg
• Intensity of contractions – the rise in intrauterine pressure above baseline brought about by a contraction
o Normally, 30-50 mmHg intensity is necessary for effective labor
o Measured externally by palpation or by internal uterine pressure catheter (IUPC)
• Contractions exert downward pressure on the fetus, pushing it against the cervix, acting as a dilating wedge.
• Longitudinal traction on the cervix by the upper portion of the uterus as it contracts and retracts leads to cervical
effacement and dilation
• Shortening and thickening of upper uterine segment leads to fetal descent
• Responsible for Cervical Change
o Effacement Shortening and thinning of the cervix (0-100%)
o Dilation Widening or opening of the cervix (0-10 cms)
o Ferguson Reflex
▪ Urge to bear down
▪ Leads to Secondary Powers – bearing down
Intensity Assessment Per Palpation
• Mild – tip of nose Slightly tense fundus (top of uterus) that is easy to indent with fingertips
• Moderate – chin Firm fundus that is difficulty to indent with fingertips
• Strong – forehead Rigid board-like fundus that is almost impossible to indent with fingertips
The 5 P’s of Labor – Position of the Laboring Woman
• Upright position – gravity aids and brings the baby down
o Standing
o Squatting
• “All fours” position – relieves pressure off the sacrum
,NURS 3358 - OB Exam 1 Study Guide.
• Lithotomy position – in stirrups
• Semi-recumbent position
• Lateral position
The 5 P’s of Labor – Psychologic Response – Maternal
• Unique to each woman • Adolescent?
• Cultural beliefs • Adoption?
• Previous experience • Relationship with spouse/significant other
• Anxiety level • Labor support – family, spouse, doula, birth attendant
• Environment • Physical/psychological condition entering labor
• Wanted or unwanted pregnancy? • Pain -tolerance/expectations for pain management
, NURS 3358 - OB Exam 1 Study Guide.
• Physiologic Adaptation to LABOR
• Maternal adaptation – Woman exhibits both objective and subjective symptoms
o Cardiovascular changes
▪ 400 ml. of blood emptied from uterus into maternal vascular system during a contraction
▪ C.O. during contractions increased by 51% by end of 1st stage
▪ C.O. peaks 10-30 min after vaginal birth and C/S; returns to prelabor baseline within one hour postpartum
▪ Slight decrease in heart rate accompanies increase in C.O.
▪ Both systolic and diastolic pressures increase during contractions; return to baseline between contractions
▪ Systolic values increase more than diastolic
▪ Supine hypotension – gravid abdomen ways too much and it smashes the aorta and vena cava; the blood and
oxygen isn’t coming through to the placenta; usually left lateral increases perfusion by getting the baby off of
those blood vessels
▪ Valsalva maneuver during pushing – Intrathoracic pressure, venous return, venous pressure. C.O. and BP and
pulse temporarily. Fetal hypoxia may occur; process reverses when woman takes a breath
o Respiratory changes
▪ Increased RR as a result of increased physical activity, pain, anxiety and increased oxygen consumption
▪ Hyperventilation can occur in response to pain – respiratory alkolosis, hypocapnia
▪ Common in transition – overwhelming urge to push
▪ How can you treat hyperventilation? Model how they should breathe
o Renal changes
▪ Spontaneous voiding may be difficult due to pain, position, pressure of baby, tissue edema
▪ Epidural influences
▪ Proteinuria of +1 normal as result of muscle tissue breakdown from work of labor
o Integumentary changes
▪ Skin flushed as a result of pain, work of labor
▪ Extreme stretching of perineum during second stage
▪ Degree of distensibility varies with individuals
▪ Lacerations and minute tears in perineum and vagina can occur
o Musculoskeletal changes
▪ Backache (unrelated to fetal position) and joint ache common as result of increased joint laxity at term
▪ Leg cramps common – never massage a pregnant woman’s calf – you could dislodge a clot
o Neurologic changes
▪ Sensorial changes can occur as woman progresses through labor
▪ Initially calm, happy about being in labor
▪ Increased seriousness as labor progresses and requires focusing on coping techniques
▪ Elation and fatigue after giving birth
▪ Endorphins effecting pain perception
o Gastrointestinal changes
▪ During labor GI motility and absorption of solid foods decreased; stomach-emptying time slowed
▪ Nausea and vomiting of undigested food after onset of labor common
▪ Nausea and vomiting common in transition and full dilation
▪ BM during labor and delivery process common
o Endocrine changes
▪ Onset of labor may be triggered by decreased progesterone & increased estrogen, prostaglandins, and oxytocin
▪ Metabolism increases
▪ Blood glucose decreases with work of labor
•
• Physiologic Adaptation to Labor – Fetal Adaption
• Fetal heart rate (FHR)
o Term gestation normal range 110-160
o Temporary accelerations and decelerations occur in response to fetal movement, contractions, vaginal exams, fetal
cord compression, etc.
• Stress to uterofetoplacental unit causes characteristic FHR patterns
• During contractions, fetal circulation decreases through spiral arterioles with subsequent decreased perfusion
through intervillous space – Fetal adaptation
o C.O. = stroke volume x heart rate
LABOR AND BIRTH PROCESSES / NURSING CARE
DURING LABOR & BIRTH
OBJECTIVES
• Describe the process of labor and the major factors affecting it and the associated nursing interventions that enhance
labor progress.
• Describe maternal and fetal adaptations to labor.
• Develop a plan of care that enhances labor progress for labor and birth.
• Review the factors included in the initial assessment of the woman in labor.
• Describe the ongoing assessment of maternal progress during the first, second, and third stages of labor with and without
risk factors identified.
• Recognize the physical and psychosocial findings indicative of maternal progress during labor.
• Describe the influence of cultural and religious beliefs and practices on the process of labor and birth.
• Discuss ways the nurse can use evidence-based practices to enhance the quality of care a woman receives during labor
and birth.
Quick Overview of Anatomy:
• Baby sits inside pelvis
Factors Affecting Labor
• The 5 P’s of Labor: Passenger, Passageway, Powers, Position of laboring woman, Physiologic response (maternal)
o Passenger: fetus and placenta
▪ Size of fetal head – fontanels allow for some movement; the baby’s head can mold to fit the mother’s pelvis; if
the baby’s head is bigger than the mom’s pelvis = cephalopelvis disproportion
▪ Fetal presentation
▪ Fetal Lie – relation of the long axis (spine) of the fetus to the long axis of the mother; longitudinal (baby’s spine
is longitudinal to mother’s spine)
▪ Attitude – the relation of the fetal body parts to one another; vertex with full flexion or general flexion ; military
▪ Position – relationship of the presenting part to the four quadrants of the mother’s pelvis
➢ First letter – tells us the location of the presenting part, in either the right or the left side of the pelvis
➢ Second letter – presenting part of the fetus
➢ Third letter – location of the presenting part to the anterior, posterior, or transverse portion of the pelvis
o Passageway: birth canal
▪ Bony pelvis
▪ Soft tissues – lower uterine segment – retraction ring
▪ Cervix, pelvic floor, vagina, introitus
Presentation – Part of the fetus that enters the pelvic inlet first
• Cephalic – head first
o Vertex – general flexion and the occiput is the general presenting part
o Face
o External cephalic version – version of the fetus from breech to vertex presentation; 36/37 weeks is ideal for
performing this
• Breech – buttock, foot, or feet
o Frank Breech
▪ Lie – Longitudinal or vertical
▪ Presentation – breech (incomplete)
▪ Presenting Part – sacrum
▪ Attitude – flexion, except for legs at knees
o Single Footling Breech
▪ Lie – Longitudinal or vertical
▪ Presentation – breech (incomplete)
▪ Presenting part – sacrum
▪ Attitude – flexion, except for one leg at hip and knee
o Complete Breech
,NURS 3358 - OB Exam 1 Study Guide.
▪ Lie – longitudinal or vertical
▪ Presentation – breech (sacrum and feet presenting)
▪ Presenting part – sacrum with feet
▪ Attitude – general flexion
• Shoulder
o Lie – transverse or horizontal
o Presentation – shoulder
o Presenting part – scapula (Sc)
o Attitude – Flexion
Presenting Part – part of fetus that lies closest to internal os
• Occiput or Mentum – hyperextended, mentum = chin
• Sacrum
• Scapula
Fetal Station – Engagement
• How close the presenting part is to the ischial spine
• If it is equal with the ischial spine 0 spine
• Negative – baby is higher up in the pelvis
• Positive – baby is further down into the pelvis
The 5 P’s of Labor – Powers:
• Primary powers – uterine contractions Frequency, duration and intensity
• Secondary powers – maternal bearing-down efforts - “Push!
Primary Powers – Contractions
• The shortening of a muscle in response to a stimulus with return to its original length
o Increment – building up; longest phase of contraction
o Acme – peak
o Decrement – letting up
o Assess for frequency, duration and intensity
• Uterine Tonus: the degree of pressure exerted by the uterine musculature as measured by intrauterine pressure
• Measured by mmHg
• Normal baseline tonus between contractions 8-12 mm Hg
• Pressure at peak of contraction ranges between 35-75 mmHg
• Intensity of contractions – the rise in intrauterine pressure above baseline brought about by a contraction
o Normally, 30-50 mmHg intensity is necessary for effective labor
o Measured externally by palpation or by internal uterine pressure catheter (IUPC)
• Contractions exert downward pressure on the fetus, pushing it against the cervix, acting as a dilating wedge.
• Longitudinal traction on the cervix by the upper portion of the uterus as it contracts and retracts leads to cervical
effacement and dilation
• Shortening and thickening of upper uterine segment leads to fetal descent
• Responsible for Cervical Change
o Effacement Shortening and thinning of the cervix (0-100%)
o Dilation Widening or opening of the cervix (0-10 cms)
o Ferguson Reflex
▪ Urge to bear down
▪ Leads to Secondary Powers – bearing down
Intensity Assessment Per Palpation
• Mild – tip of nose Slightly tense fundus (top of uterus) that is easy to indent with fingertips
• Moderate – chin Firm fundus that is difficulty to indent with fingertips
• Strong – forehead Rigid board-like fundus that is almost impossible to indent with fingertips
The 5 P’s of Labor – Position of the Laboring Woman
• Upright position – gravity aids and brings the baby down
o Standing
o Squatting
• “All fours” position – relieves pressure off the sacrum
,NURS 3358 - OB Exam 1 Study Guide.
• Lithotomy position – in stirrups
• Semi-recumbent position
• Lateral position
The 5 P’s of Labor – Psychologic Response – Maternal
• Unique to each woman • Adolescent?
• Cultural beliefs • Adoption?
• Previous experience • Relationship with spouse/significant other
• Anxiety level • Labor support – family, spouse, doula, birth attendant
• Environment • Physical/psychological condition entering labor
• Wanted or unwanted pregnancy? • Pain -tolerance/expectations for pain management
, NURS 3358 - OB Exam 1 Study Guide.
• Physiologic Adaptation to LABOR
• Maternal adaptation – Woman exhibits both objective and subjective symptoms
o Cardiovascular changes
▪ 400 ml. of blood emptied from uterus into maternal vascular system during a contraction
▪ C.O. during contractions increased by 51% by end of 1st stage
▪ C.O. peaks 10-30 min after vaginal birth and C/S; returns to prelabor baseline within one hour postpartum
▪ Slight decrease in heart rate accompanies increase in C.O.
▪ Both systolic and diastolic pressures increase during contractions; return to baseline between contractions
▪ Systolic values increase more than diastolic
▪ Supine hypotension – gravid abdomen ways too much and it smashes the aorta and vena cava; the blood and
oxygen isn’t coming through to the placenta; usually left lateral increases perfusion by getting the baby off of
those blood vessels
▪ Valsalva maneuver during pushing – Intrathoracic pressure, venous return, venous pressure. C.O. and BP and
pulse temporarily. Fetal hypoxia may occur; process reverses when woman takes a breath
o Respiratory changes
▪ Increased RR as a result of increased physical activity, pain, anxiety and increased oxygen consumption
▪ Hyperventilation can occur in response to pain – respiratory alkolosis, hypocapnia
▪ Common in transition – overwhelming urge to push
▪ How can you treat hyperventilation? Model how they should breathe
o Renal changes
▪ Spontaneous voiding may be difficult due to pain, position, pressure of baby, tissue edema
▪ Epidural influences
▪ Proteinuria of +1 normal as result of muscle tissue breakdown from work of labor
o Integumentary changes
▪ Skin flushed as a result of pain, work of labor
▪ Extreme stretching of perineum during second stage
▪ Degree of distensibility varies with individuals
▪ Lacerations and minute tears in perineum and vagina can occur
o Musculoskeletal changes
▪ Backache (unrelated to fetal position) and joint ache common as result of increased joint laxity at term
▪ Leg cramps common – never massage a pregnant woman’s calf – you could dislodge a clot
o Neurologic changes
▪ Sensorial changes can occur as woman progresses through labor
▪ Initially calm, happy about being in labor
▪ Increased seriousness as labor progresses and requires focusing on coping techniques
▪ Elation and fatigue after giving birth
▪ Endorphins effecting pain perception
o Gastrointestinal changes
▪ During labor GI motility and absorption of solid foods decreased; stomach-emptying time slowed
▪ Nausea and vomiting of undigested food after onset of labor common
▪ Nausea and vomiting common in transition and full dilation
▪ BM during labor and delivery process common
o Endocrine changes
▪ Onset of labor may be triggered by decreased progesterone & increased estrogen, prostaglandins, and oxytocin
▪ Metabolism increases
▪ Blood glucose decreases with work of labor
•
• Physiologic Adaptation to Labor – Fetal Adaption
• Fetal heart rate (FHR)
o Term gestation normal range 110-160
o Temporary accelerations and decelerations occur in response to fetal movement, contractions, vaginal exams, fetal
cord compression, etc.
• Stress to uterofetoplacental unit causes characteristic FHR patterns
• During contractions, fetal circulation decreases through spiral arterioles with subsequent decreased perfusion
through intervillous space – Fetal adaptation
o C.O. = stroke volume x heart rate
