rrtrt

• Intrapartum period


  Labor and delivery, care of the mother and the fetus during perinatal period
• Theories of onset of labor

  • The uterine muscle stretches from the increasing size of the fetus, which results in release of prostaglandins
  • The fetus presses on the cervix, which stimulates the release of oxytocin from the posterior pituitary
  • Oxytocin stimulation works together with prostaglandins to initiate contractions
  • Changes in the ratio of estrogen to progesterone occurs, increasing estrogen in relation to progesterone, which is interpreted as progesterone withdrawal
  • The placenta reaches a set age, which triggers contractions
  • Rising fetal cortisol levels reduce progesterone formation and increase prostaglandin formation
  • The fetal membrane begins to produce prostaglandins, which stimulate contractions

  
• Differentiation between true and false labor contractions

  • False contractions: Begin and remain irregular, Felt first abdominally and remain confined to the abdomen and groin, Often disappear with ambulation or sleep, Do not increase in duration, frequency, or intensity, Do not achieve cervical dilation
  • True contractions: Begin irregularly but become regular and predictable, Felt first in lower back and sweep around to the abdomen in a wave, Continue no matter what the woman's level of activity, Increase in duration, frequency, and intensity, Achieve cervical dilation

  
• The components of labor (4 P's)

  • Passage (a woman's pelvis)
  • Passenger (the fetus)
  • Power (uterine factors)
  • Psyche (a woman's psychological state)
• Passage


  The route a fetus must travel from the uterus through the cervix and vagina to the external perineum
• Pelvis


  • Shape and measurement of maternal pelvis and distensibility of birth canal
  • If a disproportion between fetus and pelvis occurs, the pelvis is the structure at fault
  • If the fetus is the cause of the disproportion, it is often not because the fetal head is too large but because it is presenting to the birth canal at less than its narrowest diameter

  
• Structure of the pelvis

  • Two innominate bones made up of: Ileum, Ischium/Ischia, Ischial Spines, Symphysis Pubis
  • Sacrum
  • Coccyx
  • False Pelvis
  • True Pelvis

  
• Types of pelvis


  • Gynecoid
  • Platypelloid
  • Anthropoid
  • Android
• Pelvic measurements


  • Diagonal Conjugate
  • Transverse Diameter of the outlet
  • Obstetric Conjugate
  • Intertuberous Diameter
  • True Conjugate
  • Diagonal Conjugate
• Soft tissue (cervix, vagina)


  Stretches and dilates under the force of contractions to accommodate the passage of the fetus
• Measurement of the pelvic inlet

  • True Conjugate
  • Diagonal Conjugate
  • Obstetric Conjugate

  
• Measurement of the pelvic outlet

  • Anteroposterior
  • Oblique
  • Transverse
  • Intertuberous Diameter

  
• Engagement


  Settling of the presenting part of a fetus far enough into the pelvis that it rests at the level of the ischial spines, the midpoint of the pelvis

  
• Degrees of engagement

  • Floating
  • Dipping
  • Station
• Passenger


  The fetus, including its size, presentation, and position
• Fetal head


  • Usually the largest part of the baby, with a significant effect on the birthing process
  • Bones of the skull are joined by membranous sutures, which allow for overlapping or 'molding' of cranial bones during birth process

  
• Structure of the fetal skull

  • Cranium: Frontal, Parietal, Occipital
  • Sphenoid, Ethmoid, Temporal

  
• Fontanelle/Fontanel


  Soft spots between the bones of the skull where bone formation isn't complete, compress during birth to aid in molding of the fetal head

  
• Diameters of the fetal skull

  • Biparietal Diameter
  • Bitemporal Diameter
  • Suboccopitobregmatic
  • Suboccipitofrontal
  • Occipitofrontal
  • Mentovertical or Occipitomental
  • Submentovertical

  
• Anterior and posterior fontanels


  Points of intersection for the sutures and are important landmarks
• Diameters of the fetal skull


  • Transverse diameters: Biparietal Diameter (9.5 cm), Bitemporal Diameter (8.2 cm)
  • AP / Longitudinal diameters: Suboccopitobregmatic (9.5 cm), Suboccipitofrontal (10 cm), Occipitofrontal (11.5 cm), Mentovertical or Occipitomental (13.5 cm), Submentovertical (11.5 cm), Submentobregmatic (9.5 cm)

  
• Complete flexion


  Allows the smallest diameter of the head to enter the pelvis
• Moderate flexion


  Causes a larger diameter to enter the pelvis
• Poor flexion


  Forces the largest diameter against the pelvic brim, so the head may be too large to enter the pelvis
• Fetal shoulders


  • May be manipulated during delivery to allow passage of one shoulder at a time
• Factors that play a part in whether a fetus is properly aligned in the pelvis and is in the best position to be born

  • Fetal attitude
  • Fetal lie
  • Fetal presentation
  • Fetal position
• Fetal attitude


  Describes the degree of flexion a fetus assumes during labor or the relation of the fetal parts to each other
• The normal fetal attitude when labor begins is with all joints in flexion
• Fetus in good attitude

  In complete flexion: spinal column bowed forward, head flexed forward so chin touches sternum, arms flexed and folded on chest, thighs flexed onto abdomen, calves pressed against posterior thighs
• This usual "fetal position" is advantageous for birth
• Fetal lie


  Relationship between the long (cephalocaudal) axis of the fetal body and the long (cephalocaudal) axis of a woman's body
• Approximately 96% of fetuses assume a longitudinal lie (with their long axis parallel to the long axis of the woman)
• Longitudinal lies


  • Cephalic
  • Breech
• Longitudinal lie is normal
• Fetal presentation


  That part of the fetus which enter the pelvis in the birth process
• Types of presentation


  • Cephalic/Vertex
  • Breech
  • Shoulder
  • Compound
• Leopold's maneuver


  • 1st Maneuver - Palpate for fetal part in fundus

  2nd Maneuver - Palpate sides of uterus to determine fetal back

  3rd Maneuver - Grasp lower abdomen to determine engagement

  4th Maneuver - Determine attitude by palpating above inguinal ligaments

  
• Cephalic/Vertex presentation


  When the head is well flexed, the suboccipitobregmatic and biparietal diameters present. When the head is not flexed but erect, the occipitofrontal and biparietal diameters present.

  
• Cephalic/Vertex presentation is 95% of deliveries
• Breech presentation


  • Frank (thighs flexed, legs extended, buttocks presenting)
  • Full or complete (thighs and legs flexed, buttocks and feet presenting)
  • Footling (one or both feet presenting)