Normal Labor and Delivery

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Normal Labor and Delivery

• Bridgett Casadaban
• July 25, 2007

2
Definitions

• Labor Uterine contractions that result in
  effacement and dilatation of the cervix.
• Braxton-Hicks Uterine contractions NOT
  associated with cervical change.
• Shorter in duration
• Less intense
• Over lower abdomen and groin
• Resolve with ambulation
• Lightening Descent of the fetal head into the
  pelvis

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Definitions

• Preterm labor Prior to 37 weeks
• Term 37 to 42 weeks
• Post term After 42 weeks
• Post dates After 40 weeks

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UVA Labor and Delivery

• 22yo G2P1 at 39 wks comes into LD complaining of
  RUCs q5 minutes x 2 hours. Diana has hooked the
  patient up to the monitor and brings the
  patients chart to you to further evaluate the
  patient. What to do next?

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UVA Labor and Delivery

• Talk with the patient
• Confirm ctx history
• LOF?
• Vaginal bleeding?
• Feeling baby move?
• Desires an epidural?
• Distance from home to hospital?
• GBS status?

q5 minutes x 2 hours
Yes
No
No
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UVA Labor and Delivery

• Examine patient
• Rule out rupture
• Check cervix

Negative pooling, nitrazine, ferning
2/50/-1
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UVA Labor and Delivery

• Formulate a plan
• You decide to allow the patient to walk around
  the hospital for 2 hours then return for a
  cervical check. What steps must you take next
  before the patient can leave LD?

Ultrasound to confirm fetal presentation
Confirm a reactive/reassuring strip
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UVA Labor and Delivery

• Patient returns in 2 hours with continued,
  uncomfortable ctxs q5 minutes. Now what?

• Recheck cervix

5/90/0
Now what?
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UVA Labor and Delivery

• Admit patient to Labor and Delivery
• Complete HP
• Obtain EFW by Leopolds
• Consents signed for delivery and potential blood
  transfusion
• Orders entered into MIS
• Clear diet
• IVFs
• TS/CBC
• GBS prophylaxis?
• Continuous EFM vs. intermittent
• Intermittent FHTs q 30 min to include a ctx and
  immediately after
• Membranes intact or SROM and well-engaged
• Continuous
• NRFHTs, SROM and poorly engaged, augmented labor,
  epidural?

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UVA Labor and Delivery

• In order to maximize the patients chance at a
  vaginal delivery it is important to understand
  the basics of labor and delivery
• Stages of labor
• Mechanics of labor
• Cardinal movements of labor
• Delivery

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Stages of Labor

• 1st Stage
• Interval between onset of labor and full cervical
  dilatation
• 2 phases
• Latent period between onset of labor and point
  at which a change in slope of rate of cervical
  dilatation is noted.
• Active Greater rate of cervical dilatation and
  usually begins around 2-3cm

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Stages of Labor

• 2nd stage
• Interval between full cervical dilatation and
  delivery
• Duration
• Nulliparous 3 hrs w/ epidural 2 hrs w/o
  epidural
• Multiparous 2 hrs w/ epidural 1 hr w/o
  epidural
• 3rd stage
• Delivery of the placenta and membranes
• Duration maximum of 30 minutes

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Normal Labor and Delivery

• In order to maximize the patients chance at a
  vaginal delivery it is important to understand
  the basics of labor and delivery
• Stages of labor
• Mechanics of labor
• Cardinal movements of labor
• Delivery

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Mechanics of Labor

• The Powers
• Forces generated by uterine musculature
• Frequency, amplitude, and duration of ctxs
• Observation, manual palpation, tocodynamometry,
  intrauterine pressure catheter (IUPC)
• Measured in Montevideo units
• Average strength of ctxs (mmHG) x no. of ctxs
  in 10 minutes
• Adequate 200-250 MVUs

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Mechanics of Labor

• Passenger
• Fetal size
• Abdominal palpation or Ultrasound
• Macrosomia (gt4500g) associated w/ failure to
  progress
• Lie
• Longitudinal axis of fetus relative to
  longitudinal axis of uterus
• Longitudinal, transverse or oblique
• Presentation
• Fetal part that directly overlies pelvic inlet
• Cephalic, breech, or shoulder
• Compound presence of gt1 fetal part overlying
  the pelvic inlet
• Funic umbilical cord presenting at pelvic inlet
• Malpresentation any presentation that is not
  cephalic with occiput leading

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Mechanics of Labor

• Passenger (cont)
• Attitude
• Position of head with regard to fetal spine (ie
  degree of flexion or extension)
• Flexion allows smallest diameter of fetal head to
  present at pelvic inlet
• Position
• Relationship of a nominated site of presenting
  part to denominating location on internal pelvis
• Example cephalic presentation

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Mechanics of Labor
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Mechanics of Labor

• Passenger (cont.)
• Station
• Measure of descent of presenting part of the
  fetus through the birth canal.
• Multifetal Pregnancy
• Increase probability of abnormal lie and
  malpresentation in labor

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Mechanics of Labor

• Passenger (cont.)
• Leopolds maneuvers
• 1 Correct dextrorotation of the uterus with
  the back of one hand and delineate the fundus
  with the other to determine gestational age
  and/or appropriate size.
• 2 Run hands down maternal abdomen on either
  side of fetus to determine fetal lie, identifying
  small parts and fetal spine
• 3 Firmly grasp upper and lower poles of fetus
  by placing fingers at uterine fundus and above
  symphysis to determine presentation and fetal
  size.
• 4 Move hands in bilaterally from anterior
  superior iliac crests to determine whether or not
  the presenting part of the fetus is engaged in
  maternal pelvis.
• Head regarded as unengaged if examiners hands
  are see to converge below fetal head.

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Mechanics of Labor

• Passenger (cont.)

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Mechanics of Labor

• Passage
• Bony pelvis soft tissues
• X-ray pelvimetry now rarely used, having been
  replaced by a trial of labor
• 4 types of the female bony pelvis

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Normal Labor and Delivery

• In order to maximize the patients chance at a
  vaginal delivery it is important to understand
  the basics of labor and delivery
• Stages of labor
• Mechanics of labor
• Cardinal movements of labor
• Delivery

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Cardinal Movements of Labor

• Engagement
• Passage of widest diameter of presenting part to
  level below the plane of the pelvic inlet
• 0 station
• Occurs earlier in nulliparous women (36 wks)
• Descent
• Downward passage of presenting part through the
  pelvis.
• Flexion
• Occurs passively as the head descends due to the
  shape of the bony pelvis and resistance of pelvic
  floor soft tissues
• Allows smallest diameter of fetal head to pass
  through the pelvis.

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Cardinal Movements of Labor

• Internal Rotation
• Rotation of presenting part from original
  position (transverse) to anteroposterior position
• Extension
• Occurs once fetus has descended to the level of
  the introitus
• Base of occiput in contact with inferior margin
  of symphysis pubis
• External Rotation
• Return of fetal head to correct anatomic position
  in relation to the fetal torso
• Expulsion
• Delivery of rest of fetus
• Anterior shoulder delivered first with rotation
  under the symphysis pubis

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Cardinal Movements of Labor
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Normal Labor and Delivery

• In order to maximize the patients chance at a
  vaginal delivery it is important to understand
  the basics of labor and delivery
• Stages of labor
• Mechanics of labor
• Cardinal movements of labor
• Delivery

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How to effectively deliver a baby

• Prepare for the delivery taking into account
  parity, progression of labor, presentation of
  fetus, complications of labor
• When head crowns and delivery is eminent, protect
  the perineum downward pressure to keep head
  flexed
• Ritgens maneuver my help if delay in delivery of
  the fetal head
• Sterile towel used to palpate fetal chin through
  the rectum to apply upward pressure to facilitate
  extension of fetal head
• After delivery of head
• Allow for external rotation (restitution).
• Reduce nuchal cord
• Suction fetal mouth and nares
• After clearing fetal airway
• Place a hand on each parietal eminence to apply
  downward traction to deliver anterior shoulder
• Followed by upward traction to deliver posterior
  shoulder

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How to effectively deliver a baby

• After complete delivery of infant
• Cradle in a single arm below the perineum to
  allow maximal blood transfer to infant
• Delivery of the placenta
• 3 classic signs of placental separation
• Lengthening of the umbilical cord
• Gush of blood from vagina
• Change in shape of the uterine fundus to a more
  globular appearance
• Active management of 3rd stage has been shown to
  reduce total blood loss
• Brandt-Andrews Maneuver abdominal hand secures
  the uterine fundus to prevent uterine inversion
  while the other hand exerts sustained downward
  traction on umbilical cord
• Crede maneuver cord is fixed with lower hand
  while the uterine fundus is secured and sustained
  upward traction is applied using abdominal hand

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How to effectively deliver a baby

• Inspect the placenta
• Abnormalities of lobulation
• Site of insertion of umbilical cord into the
  placenta
• Marginal insertion inserts into edge of placenta
• Membranous insertion vessels course through the
  membranes prior to attaching to placental disk
• Length (50-60cm)
• 2 arteries and 1 vein
• Single umbilical artery associated with 20 risk
  of other structural anomalies.

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