NORMAL LABOR Flashcards
Criteria for Diagnosis
- Uterine contractions (1 in 10 mins; 4 in 20 mins) by direct observation or by electronic fetal monitor
- at least 200 Montevideo units (MVU) - Documented progressive changes in cervical dilatation and effacement
- Cervical EFFACEMENT > 70-80%
- Cervical DILATATION > 3 cm
Bishop Score
used to predict labor induction
<5 - unfavorable
>9 - successful induction
Latent Phase
Onset of labor to about 3-5 cm dilatation
Factors that affect Latent Phase duration
excessive sedation or epidural anesthesia
unfavorable cervical condition
false labor
Active Phase
From 3-5 cm dilatation up to full dilatation
Factors that affect Active Phase duration
Epidural anesthesia - prolonged labor curve to 1 hr
Maternal obesity - prolonged to 30-60 minutes
Maternal fear - prolonged to 45 minutes
Cardinal Movements
Engagement Descent Flexion Internal Rotation Extension External Rotation (Restitution) Expulsion
Engagement
BPD passes through the pelvic inlet
Descent
First requisite for birth of the newborn
Four forces of Descent
pressure of the amniotic fluid
direct pressure of the fundus upon the breech with contraction
bearing down efforts of maternal abdominal muscles
extension and straightening of the fetal body
Flexion
descending head meets resistance (cervix, pelvic walls and pelvic floor)
Internal Rotation
occiput movers toward the symphysis pubis
Extension
2 forces
- uterus exertion – acts more posteriorly
- resistant pelvic floor and symphysis - acts more anteriorly
External Rotation
rotation of the fetal body
bring bisacromial diameter into relation with the anteroposterior diameter of the pelvic outlet
Expulsion
anterior shoulder appears under the symphysis pubis
after delivery of the shoulders the rest of the body quickly passes
Goals of 3rd Stage Labor
delivery of an intact placenta
avoidance of uterine inversion
avoidance of post-partum hemorrhage
Signs of Placental Separation
- globular and firmer fundus (Calkin’s sign)
- sudden gush of blood
- lengthening of umbilical cord
- rise of uterus into the abdomen
EINC
- Immediate and thorough drying
- Early skin-to-skin contact
- Properly timed cord clamping
- Non-separation for early breastfeeding (for 6 hrs)
- eye care
- immunization
- rooming in
Indications for Episiotomy
- Expedite delivery in the 2nd stage of labor
- When spontaneous delivery is likely
- Maternal or fetal distress
- Breech position
- Assisted forces
- Large baby
- Maternal exhaustion
Perineal Lacerations
1st -4th degree
1st Degree of Perineal Laceration
Fourchette, perineal skin and vaginal mucous membrane but NOT the underlying fascia and muscle
2nd Degree of Perineal Laceration
Skin and mucous membrane + fascia and muscles of the perineal body
3rd Degree of Perineal Laceration
Lacerations extend through skin, mucous membrane, perineal body and anal sphincter
4th Degree of Perineal Laceration
Extension of laceration through the rectal mucosa to expose lumen of the rectum
Functional Divisions of Labor
Preparatory
Dilatational
Pelvic Division
Preparatory Division
similar to phase 1
latent phase + acceleration phase
little dilatation of the cervix
sedation and analgesia - capable of arresting this labor division
Dilatational Division
active phase
rapid dilatational rate of cervix (maximum dilatation =maximum slope)
UNAFFECTED by anesthesia and sedation
2 Phases of Dilatational Division
Latent Phase
Active Phase
Latent Phase
corresponds to the PREPARATORY division
Active Phase
corresponds to the DILATATIONAL division
Division of Active Phase
Acceleration Phase
Phase of Maximum Slope
Deceleration Phase
Prolonged Latent Phase
nulliparas - 20 hrs
multiparas - 14 hrs
Threshold for active labor
uterine contractions and cervical dilatation of 3-5 cm or more
Protraction
slow rate of cervical dilatation or descent
- nulliparas - < 1.2 cm dilatation/hr
- multiparas < 1.5 cm dilatation/hr or 2 descent per hour
Pelvic Division
active phase
deceleration + 2nd stage of labor
cardinal movements of fetus occurs
Acceleration
4-5 cm
predictive of outcome labor
Maximum Slope
7-9 cm
descent of nullipara occurs here
Deceleration
8-9 cm
heralds entry into the pelvic division of labor
Arrest of Dilatation
2 h without cervical change
Arrest of Descent
1 h without fetal descent
Injury to only the vaginal epithelium or perineal skin
1st degree perineal laceration
injury to perineum that spares the anal sphincter complex but involves the perineal muscles - bulbospongiosus and superficial transverse perineal muscles
2nd degree perineal laceration
< 50 percent external anal sphincter (EAS) tear
3a
> 50 percent EAS tear
3b
EAS plus internal anal sphincter (lAS) tears
3c
Laceration of the perineal body, entire anal sphincter complex and anorectal mucosa
4th degree perineal laceration
