Stages of Labor

LABOR

Labor is a series of rhythmic, progressive Labor is a series of rhythmic, progressive contractions of the uterus that gradually move contractions of the uterus that gradually move the fetus through the lower part of the uterus the fetus through the lower part of the uterus (cervix) and birth canal (vagina) to the outside (cervix) and birth canal (vagina) to the outside

world.world.

The Physiology of LaborPOSSIBLE CAUSES OF LABOR ONSET

• Progesterone Withdrawal Hypothesis• Prostaglandin Hypothesis• Corticotropin-Releasing Hormone

Premonitory Signs of Labor

• 1. LIGHTENING – describes the effects that occur when the fetus begins to settle into the pelvic inlet (engagement)

• -With fetal descent the uterus moves downward, and the fundus no longer presses on the diaphragm which allows breathing to become easier.

2. BRAXTON HICK’S CONTRACTIONS – (the irregular, intermittent that have been occuring throughout the pregnancy) may become uncomfortable. Pain is focused on the abdomen and groin

3. CERVICAL CHANGES – weakening and softening of the cervix brought about by breaking down of collagen fibers by certain enzymes; ability to bind together decreases; water content of the cervix increases

4. BLOODY SHOW – pink-tinged secretions, small amount of blood loss from the exposed cervical capillaries after a mucous plug is expelled– Bloody show is considered a sign that labor will

begin within 24 to 48 hours

5. RUPTURE OF MEMBRANES – amniotic membranes rupture and the woman experiences labor within 24 hours.

6. SUDDEN BURST OF ENERGY- 24 -48 hours before labor

• Induction of LaborInduction of Labor • InductionInduction of labor is the deliberate starting of of labor is the deliberate starting of

uterine contractions before they begin on their uterine contractions before they begin on their own.own.

• AugmentationAugmentation is the administration of synthetic is the administration of synthetic oxytocin to enhance existing labor.oxytocin to enhance existing labor.

MethodsMethods• Cervical ripeningCervical ripening• AmniotomyAmniotomy• OxytocinOxytocin

Monitoring Techniques During Labor

FHR auscultationFetoscopeDoppler

EFM

Factors Affecting Labor(5 Ps)

• 1.Passenger = the size, presentation,and position of the fetus.

• 2. Passageway = shape and measurement of maternal pelvis.

• 3. Powers = forces of labor, acting in concert, to expel the fetus and placenta.

• 4. Placenta = position of placenta• 5. Psyche or Psychologic Response = A woman

who is relaxed, aware, and participating in the birth usually has a shorter, less intense labor.

1. PASSENGER

• Attitude: This refers to the posturing of the joints and relation of fetal parts to one another. The normal fetal attitude when labor begins is with all joints in flexion.

• Lie: relationship of cephalocaudal axis (fetal spine) of the fetus to the cephalocaudal axis of the mother (maternal spine) i.e., transverse, oblique, or longitudinal (parallel).

• Presentation: This describes the part on the fetus lying over the inlet of the pelvic or at the cervical os.

Types of Presentation

1. CEPHALIC = the fetal head presents itself to the passage, occurs in 97% of birthsClassified as:

1. Vertex – most common; fetal head is completely flexed; smallest diameter of the fetal head (suboccipitobregmatic ) presents to the maternal pelvis

2. Military – fetal head is neither flexed nor extended; top of the head is the presenting part

3. Brow – fetal head is partially extended; sinciput is the presenting part

4. Face – fetal head completely extended; face is the presenting part2. BREECH (buttocks) or (lower extremities)

a.Frank: thighs flexed, legs extended on anterior surface, buttocks presenting

b.Full or complete: thighs and legs flexed,buttocks and feet presenting(squatting)

c. Footling: one or both feet are presenting3. SHOULDER (Scapula).CS

Position: relationship of reference point on fetal presenting part to maternal bony pelvis. Maternal bony pelvis divided into 4 quadrants

(R and L anterior, R and L posterior)

2. PASSAGEWAY= shape and measurement of maternal pelvis and

distensibility of birth canal.

False Pelvis

• Shallow upper basin of the pelvis

• Supports the enlarging uterus

True Pelvis

• Consists of the pelvic inlet, pelvic cavity, and pelvic outlet.

• Influence the conduct and progress of labor and delivery

•Engagement: This occurs when the largest diameter of the presenting part reaches or passes through the inlet of the true pelvis.

•Station: refers to the relationship of the presenting part to an imaginary line drawn between the ischial spines of the maternal pelvis measured in + or - centimeters.

3. POWER

• Major forces: Involuntary and voluntary• Involuntary: includes frequency, regularity,

intensity and duration.• Voluntary: bearing-down efforts. The

contraction of levator ani muscles.

Uterine contraction

3 phases of labor contraction

1. INCREMENT – building up of the contraction (longest phase)

2. ACME – peak of the contraction3. DECREMENT – letting up of the contraction

Terms to describe uterine contractions during labor

• DURATION - measured from the beginning of a contraction to the completion of the same contraction

• FREQUENCY- refers to the time between the beginning of one contraction and the beginning of the next contraction

• INTERVAL- refers to the time between the end of one contraction to the beginning of the next contraction

• INTENSITY – refers to the strength of the contraction during acme.

4. POSITION

• Maternal positioning during labor• Influence pelvic size and contours• Affects pelvic joints, facilitate descent and rotation• E.g. squatting – enlarges the pelvic outlet by

approximately 25%• Kneeling removes pressure on the maternal vena

cava and assists to rotate the fetus in the posterior position (Breslin and Lucas, 2003)

Supine/ Lithotomy

• Non-moving, back lying positions are not healthy ( Simkin, 2002)

• To conserve energy and not to tire themselves• To keep track of ambulating women• Facilitate vaginal examination

Upright/ lateral position• Reduce duration of 2nd stage of labor• Reduce number of assisted deliveries (vacuum,

forceps)• Reduce episiotomies and perineal tears• Reduces abnormal fetal heart patterns• Increase comfort/reduce request for pain

medications• Enhance a sense of control• Alters shape, size of pelvis; facilitates descent• Reduce length of labor (Gupta & Hofmeyr,2003)

5. PSYCHE The woman feels confident in her ability to cope and find ways to work with the contractions, the labor process is enhanced.

If the laboring woman becomes fearful or has intense pain, she may become tense and fight the contractions. This situation often becomes a cycle of fear, tension, and pain that interferes with the progress of labor.

Difference between true and false laborTRUE LABORTRUE LABOR FALSE LABORFALSE LABOR

ContractionContraction Regular, increasing Regular, increasing frequency and frequency and intensity, shortening of intensity, shortening of intervalinterval

Irregular, no Irregular, no change in change in frequency, frequency, duration and duration and intensityintensity

DiscomfortDiscomfort Radiates from back Radiates from back around the abdomenaround the abdomen

Pain at abdomenPain at abdomen

Rest/Rest/

ActivityActivity

Contraction does not Contraction does not decrease with rest or decrease with rest or activityactivity

Contraction may Contraction may lessen with activity lessen with activity or rest.or rest.

CervixCervix Progressive Progressive effacement and effacement and dilatation of cervixdilatation of cervix

Cervical changes Cervical changes do not occur yetdo not occur yet

• Four Stages of Labor:

1. First Stage: Dilationa. Early Labor (latent phase)b. Active Labor (active phase)c. Transition (Transition phase)

2. Second Stage: Birth3. Third Stage: Delivery of Placenta4. Fourth Stage: Recovery

FIRST STAGE =From the beginning of labor to the full opening (dilation)of the cervix—to about

4inches(10centimeters).

Initial (Latent) Phase • Contractions begin which are

usually mild lasting from 15-20 sec.; frequency every 10-20 mins.

• Discomfort is minimal. • The cervix thins and opens to

about 11/2 inches (4 centimeters). • This phase lasts an average of 12

hours in a first pregnancy and 5 hours in subsequent pregnancies.

Active Phase   The cervix opens from about 4 centimeters to 8 centimeters.   The presenting part of the baby, usually the head, begins to descend into the woman's pelvis. Transition PhaseCervix (8- full dilatation 10cm)    The woman begins to feel the urge to push as the baby descends.

Comfort Measures for the Laboring WomanComfort Measures for the Laboring Woman

Do not leave alone in active labor.Do not leave alone in active labor. Change soiled and damp linen promptly.Change soiled and damp linen promptly. Provide mouth care.Provide mouth care. Ice chips, lubricate lips.Ice chips, lubricate lips. Keep room cool, uncluttered, quiet and privacy.Keep room cool, uncluttered, quiet and privacy. Promote participation of coach.Promote participation of coach.

When to position your patient

• S – udden gush of blood• U – rge to defecate• B – loody show• I – ncrease in contractions• R – upture of Membranes• B – earing down• A – nal dilatation

SECOND STAGEFrom the complete opening of the cervix to delivery of

the baby. This stage averages about 45 to 60 minutes in a first pregnancy and 15 to 30 minutes in subsequent

pregnancies. CROWNING occurs when the fetal head is encircled by

the external opening of the vagina (introitus), and it means birth is imminent

Mechanism of a spontaneous vaginal delivery/ Cardinal

movements

• Definition: A mechanism of labor is a series Definition: A mechanism of labor is a series of passive, adaptive movements of the fetal of passive, adaptive movements of the fetal head and shoulders through the birth canal. head and shoulders through the birth canal.

Mechanisms of Labor• Descent• Engagement• Flexion• Internal Rotation• Extension• Restitution• External Rotation• Expulsion

THIRD STAGE (Placental stage)From delivery of the baby to delivery of the placenta. This stage usually lasts only a few minutes but may last up to

30 minutes.

• Made up of 15-20 lobes called cotyledons

• 2 mechanisms of placental separation

• 1. SCHULTZE – separates from the inside to the outer margin; expelled with the fetal side ; “Shiny”

• 2. DUNCAN- separates from the outer margins inward, rolls up and presents sideways with the maternal surface; “Dirty”

Fourth stage• Recovery: The woman is observed frequently for

signs of hemorrhage or other complications; 1-4 hours after birth

• Hemodynamic changes occur• Blood loss ranges from 250-500ml• Uterus remains contracted in the midline

Possible complications for the mother include:

• rupture (tearing) of the uterus • hemorrhage (heavy bleeding) after the

delivery • bruising or tearing of the cervix or vagina • tearing of the rectum • bruising or irritation of the bladder.

Maternal Adaptation during the Postpartum Period

• Normal uterine involution occurs at a predictable rate. One hour after chilbirth, the fundus is at the level of the umbilicus.

• On the 1st postpartum day, the fundus is approximately 1 fingerbreadth or 1 cm below the level of the umbilicus.

• Thereafter, it descends downward at the rate of 1 cm per day until it becomes a pelvic organ again on the 10th day postpartum.

• Lochia rubra, serosa and alba.

• Normal blood loss during NSVD 300 to 500 ml.

• CS: 500 to 1,000 mL.

Maternal Role Development• Taking In Phase Mother is dependent, has difficult making decisions and

needs assistance with self-care. Can last several hours to days.

• Taking Hold PhaseAfter she has rested and recovered from stress of

delivery, the new mother has energy for the infant. Lasts 2 days to several weeks.

• Letting Go PhaseFamily relationships are adjusted to accommodate the

infant. Give up the fantasy child and gets to know the real child.

• “Postpartum blues” = a temporary depression that usually begins on the 3rd day and lasts for 2-3 days.

S/S: tearful, difficulty sleeping and eating, and feel generally down.

Psychological adjustment, plus fatigue, disturbed sleep patterns, and discomfort may contribute.

Focus of early postpartum period:1. Preventing and detecting hemorrhage2. Treating pain3. Preventing infection4. Detecting and treating urinary retention5. Promoting sleep6. Promoting healthy parental-newborn attachment.

POSTPARTUM COMPLICATIONS

1. HEMORRHAGE - 1-4 hrs postpartum is the most critical stage

Causes:

• a. Laceration

• b. Placental retention

• c. Uterine rupture

• d. Uterine inversion

• e. Uterine atony

2. INFECTIONS

• a. Endometritis – Endometriosis is the growth of endometrial tissue outside the uterus. When infected, it is called endometritis.

• Clinical manifestations:

• foul smelling vaginal discharge

• fever & chills

• profuse bleeding

• b. Episiotomy Infection

Operative Obstetrical Procedures

Forceps Delivery

Forceps Delivery – method of delivering infants through the use of forceps extraction

- 2 double-crossed, spoonlike articulated blades that are used to assist in delivery of fetal head

- may cause damage on the facial nerve of the baby

Vacuum DeliveryVacuum Delivery – method of delivering an infant using a vacuum applied over the scalp of the baby

- may cause caput succedaneum

Cesarean SectionCesarean SectionIn the case of severe obstetric emergencies, the In the case of severe obstetric emergencies, the time from decision to delivery is ideally within 30 time from decision to delivery is ideally within 30

minutes minutes ..

3 types

a. Low Segment CS – method os choice since lower segment is thinner, fewer bld vessels, passive during labor

b. Classical CS – indicated for transverse lie, placenta previa, adhesion of tissues

c. Pfannenstiel or bikini