Labor Disorders Flashcards
Onset of regular painful uterine contractions up to full cervical dilatation (0-10 cm)
Firsr stage of labor
Full cervical dilatation up to full expulsion of the baby
Second stage of labor
Expulsion of the baby up to the delivery of the placenta
Third stage of labor
Phases of the first stage of labor
Latent
Active
0-4 cm dilatation
0-8 HOURS
Latent phase
4-10 cm dilatation
8-16 HOURS
Active phase
Active phase 3 subphases
Acceleration
Phase of Maximum Slope
Deceleration Phase
Rapid cervical dilatation
4-6cm, 2-3 hours
Acceleration Phase of Active Phase of First Stage of Labor
Descent of the presenting part (can be head or breach) Happens at midmaximum slope Fastest rate of dilatation 6-8cm 30 minutes to 1 hour
Phase of Maximum Slope of the Active Phase of the First Stage of Labor
Maximum descent Diagnosis of failure of descent Dilatation slows down 8-10 cm 2-3 hours
Deceleration phase of the Active Phase of the First Stage of Labor
Functional Divisions of Labor
Preparatory
Dilatational
Pelvic
The uterus is prepared for dilatation and effacement (0-6cm)
Coincides with latent phase and acceleration phase
Preparatory division (Functional)
Where maximum dilatation occurs which corresponds to the phase of maximum slope
Dilatational division (Functional division)
Where there is maximum descent at 8cm of dilatation
Presenting part is in the pelvis already
Coincides with the deceleration phase and second stage of labor
Pelvic division (Functional)
Difficult labor
Abnormally slow labor progress
Dystocia
Dystocia four distinct abnormalities
Abnormalities of the expulsive force
Abnormalities of presentation, position or development of fetus
Abnormalities of maternal bony pelvis
Abnormalities of Soft tissue of the reproductive tract that form the obstacle to fetal descent
Complications of dystocia
Infection - chorioamnionitis of endometrium and fetal infection
Uterine atony - tired, postpartum hemorrhage
Uterine rupture - contraction against obstruction
Pathologic retraction ring (band) - stretching of uterine segment, prelude to rupture
Fistula - impacted head, ischemia of lower vaginal wall (rectovaginal)
Pelvic floor injury
LE injury - dorsal lithotomy (sciatic and peroneal nerve)
Feral injury
Distance between two parietal diameter (9.5 cm)
Biparieral diameter
Bregma to subocciput measuring 9.5 cm
Shortest diameter
Suboccipitobregmatic
Frontal bone to occipital bone
12 cm
Frontooccipital/occipitofrontal
Mentum to occiput
13.5 cm
We don’t want this
Mentooccipital/occipitomental
When the most dependent portion of the presenting part is at the level of ischial spine
Passage of the biparieral diameter through pelvic inlet
Station:
5th station above the spine
Engagement
Station 0
Contractions would keep pushing the baby down but the baby encounters the pelvic floor (resistance) leading to flexion of the head
Descent
The baby has to flex its head to adapt to the pelvis from the Frontooccipital (12) diameter to the Suboccipitobregmatic (9.5) now that presents
Flexion
The head must do this movement so that the presenting diameter becomes the Biparieral diameter (9.5) from SOB (9.5)
Traverses the bispinous diameter (9-9.5)
Uses symphysis pubis as fulcrum for extension so that it can come out of the introitus
You still cannot see the baby at this point
Internal rotation
Point at which the baby is seen
Head on introitus
Sharply flexed head reaches vulva and goes extension
Failure to extend would lead to head impingement on posterior portion of perineum
Extension
Body of the baby does not move. Only the head.
Happens very fast.
Rotation of the fetal body and serves to bring its BISACROMIAL DIAMETER (outermost shoulder) into relation with the anteroposterior diameter of pelvic outlet.
External rotation
Head is the biggest part of the baby so when it has already passed, everything else can easily pass through.
Know the cephalometric measurements so you can justify to the mother that she should undergo Caesarian section
Expulsion/delivery
Occiput presentation
Normal, most common
Fully flexed head
SOB 9.5
BPD 9.5
Sinciput presentation/Military presentation
Head is not flexed
Inadequate or contracted pelvis
Big fetal head despite adequate pelvis
When IE is done, this is seen
Poor prognosis
Tx
Frontooccipital diameter 12.5
Diamond shaped fontanel instead of triangle
CS
Brow presentation
Poorest prognosis
Midway between full flexion and extension
Neck slightly extended
On IE?
Tx
Mentooccipital 13.5 NO
Brow prominence
CS
Face
Fetal head too extended
IE?
Chin protrusion
9.5 cm
SOB
Mouth
Cephalometric measurements that may pass through. 9.5 cm
Occiput
Face
Face presentation where mentum is above the symphysis pubis
Tx
NSD
Symphysis as fulcrum
Face presentation where mentum is posterior
Tx
Mentum posterior
Coccyx obstructs the flexion snd passage of head, CS
Hand is lying in front of vertex
Not risk factor for dystocia or CS
Hand and arm may retract from the birth canal and the head may descend normally
Sweep up the hands and labor can proceed
Compound presentation
Right acromiodorsoposterior (RAPD)
Shoulder of fetus is to the mother’s right, and the back is posterior.
This baby cannot be delivered vaginally.
Tx
Transverse lie
CS
The primary purpose of uterine contraction is to
Efface the cervix (thinning and eventually obliterating) at the SECOND STAGE
Baseline uterine pressure - peak contracture pressure for each contraction in a 10-minute window
Add pressures generated by each contraction
Montevideo units
> /= 200 Montevideo units for 10 minutes equals
Less than 200 Montevideo units
Adequate contraction
Abnormal (hypotonic or inadequate uterine contraction)
Abnormalities in power
Hypotonic uterine dysfunction
Hypertonic incoordinate uterine dysfunction
Contractions are not enough
Weak, short, infrequent, inadequate and will not lead to cervical dilatation
<200 Montevideo units
Hypotonic uterine dysfunction
Hypotonic uterine dysfunction causes
Excessive anesthesia Overworked uterus (prolonged labor) Anemia Abnormal uterine contour Malpositioning/malpresentation Pelvic contraction Infection Full bladder or rectum
Hypotonic Uterine Dysfunction Tx
Amniotomy
Uteritonic (oxytocin infusion) if without CPD
Releases prostaglandin which aid in uterine contraction
Amniotomy
Very strong, yet uncoordinated uterine contractions
Strong >200 Montevideo units
Prolonged, frequent but asynchronous, irregular
Too much contraction compromises blood flow to baby due to compression of blood vessels -> fetal distress
Excessive oxytocin, abruptio placenta
Hypertonic Incoordinate Uterine dysfunction
Hypertonic Incoordinate Uterine Dysfunction Tx
Stop oxytocin, tocolytics or sedation
CS if with distress
May cause insignificant but prolonged first and second stages
Pain of labor does not go away, it is just less pain
Epidural anesthesia
Epidural anesthesia is given only at this phase so there will be no chance for delay in contraction
Active phase
Abnormalities in power causes
Epidural anesthesia
Maternal position - ambulation
Birthing position - upright (delivery shorter by 4 minutes); dorsal lithotomy (prolonged labor, affect contraction and power)
Inlet clinical pelvimetry
Diagonal conjugate
Obstetric conjugate
From inferior border of symphysis pubis to the sacral promontory
Only clinically measurable diameter of the inlet
Diagonal conjugate
Sacra promontory to the back of the symphysis pubis
Where baby’s head will pass through
Cannot be directly measured by IE
Diagonal conjugate - 1.5
Obstetric conjugate
An inlet is contracted if the
DC
OC
DC <12
OC <10
Baby may not be able to pass through engagement
Only cardinal movement that involves the inlet
Engagement
Diagonal conjugate must be
11.5 to 12 cm
so Obstetric conjugate will be 10-15 cm
so BPD 9.5 can pass
Midpelvis pelvimetry
Bispinous diameter - clinically measurable
Posterior sagittal diameter
A midpelvis is said to be contracted if it measures
<10 cm
bec SOB, BPD is 9.5
Cannot be measured clinically
Determines ROOMINESS of pelvis
Midpoint of bispinous diameter and distance from that point to the sacrum
Where all cardinal movements as far as internal rotation except engagement take place
Posterior sagittal diameter
Posterior sagittal diameter is determined by assessing the
Width of the sacrosciatic notch
Indirect measure of the posterior sagittal diameter
Place 2 fingers in the space, must be at least 4.5 cm
Concavity of the midplane - flexion, internal rotation occurs
This movement is needed so head can pass through bispinous diameter
Internal rotation
Distance between the two tuberosities
Place fist in between the space
Must be at least 9-10 cm
<8, contracted
Bituberous diameter
Does not go beyond 4 cm >20 h in Nulliparas
Does not go behond 4cm >14 h in Multiparas
Tx?
Prolonged latent phase
Dystocia but CS not yet indicated
Bed rest/oxytocin
Exceptional treatment for prolonged latent phase
> 20 h Nulliparas
14 h Multiparas
Oxytocin
Caesarian delivery for urgent problems
Rate of cervical dilatation <1.2 cm/h in Nullipara
Rate of cervical dilatation <1.5 cm/h in Multipara
Protracted active phase dilatation
Rate of descent <1 cm/h in Nulliparas
Rate of descent <2 cm/h in Multiparas
Protracted descent
Diagnose only if 8cm dilated!!
Protracted active-phase dilatation
Protracted descent
Tx
Expectant and support
CS for CPD
> 3 h to reach 10 cm in Nullipara
>1 h to reach 10 cm in Multipara
Prolonged deceleration phase
> 2 h in Nullipara
2 h in Multipara
No change in cervical dilatation for 2h
Secondary arrest of dilatation
> 1 h in Nullipara
1 h in Multipara
At 8cm head descends but STOPS
Stops at a station for more than an hour
Must have descended first!
8cm station 0 -> after an hour 9cm station +1 -> after an hour 10 cm, station +1
Arrest of descent
No descent in deceleration phase or second stage
At 8 cm station 0 -> after an hour 10 cm station 0
As long as there is no descent from 8cm onwards
Failure of descent
Prolonged deceleration phase
Secondary arrest of dilatation
Arrest of descent
Failure of descent
Tx
Evaluate for CPD
CPD: Caesarian
No CPD: oxytocin
Rest if exhausted
CS
Dilatation disorders are diagnosed after
4 cm of dilatation (Active phase) of First Stage of Labor
Disorders of descent are diagnosed only after
8 cm of dilatation (Deceleration phase) of Active phase of the First stage of labor
Consider protracted descent
prolonged deceleration phase
arrest of descent and failure of descent
once cervix is
> 8 cm
Record of all the clinical observations made on a woman in labor, the central feature of which is the graphic recording of the dilatation of the cervix as assessed by vaginal examination, and descent of the head
Partograph
Extremely rapid labor and delivery
Delivery of fetus in <3 hours
Dilatation of the cervix of 5 cm/h
Precipitous labor
Complications of precipitous labor
Uterine atony
Genital tract lacerations
Placental abruption
Amniotic fluid embolism - vigorous contraction
Intracranial trauma, palsy, birth injuries
