labor and delivery

1. NORMAL LABOR
AND DELIVERY
ZARIEH DAWN L. NOVELA, M.D.
OB-GYN RESIDENT – FIRSTYEAR
MANDALUYONG CITY MEDICAL CENTER
JUNE 15, 2018

2. LABOR
- “troublesome effort or suffering”
- rhythmic contractions which bring
about gradual effacement and dilatation
of the cervix and ends with the expulsion
of the fetus
- progressive increase in frequency,
intensity and duration

3. LABOR
■ (+) Cervical dilatation, (-) uterine
contractions = cervical incompetence
■ (+) uterine contractions, (-) cervical
changes = Not in labor

4. LABOR
Criteria
1. Uterine contractions at least 1 in 10
minutes or 4 in 20 minutes
2. Documented progressive changes in
cervical dilatation and effacement
3. Cervical effacement >70-80%
4. Cervical dilatation >3 cm

5. MECHANISMS OF LABOR
■ At the onset of labor, the
position of the fetus with
respect to the birth canal is
critical to the route of delivery.
■ IMPORTANT RELATIONSHIPS:
– Fetal lie, presentation,
attitude and position

6. Fetal Lie
■ Relationship of fetal long axis to
that of the mother
■ Transverse Lie predisposing
factor
– Multiparity, placenta previa,
hydramnioas, uterine
anomalies

7. Fetal Presentation
■ Portion of the fetal body lying
over the inlet/birth canal

8. Fetal Presentation
■ Cephalic presentation

9. Fetal Attitude
■ Relation of fetal parts to one
another
■ Fetus forms an ovoid mass
■ Results from the mode of fetal
growth and accommodation to
the uterine cavity

10. Fetal Position
■ Relation of the fetal presenting
part to the R and L side of birth
canal
– Vertex: occiput
– Breech: sacrum
– Face: mentum
– Shoulder: acromion

11. Fetal Position

12. Fetal Position

13. Fetal Position

14. Leopold Maneuver
1st: Fundal grip: to assess fetal lie, and determine w/c part of fetal pole lies in fundus
2nd: Umbilical grip: on which side is the fetal back
3rd: Pawlicks grip: confirmation of fetal presentation, what fetal part lies above the pelvic inlet
4th: pelvic grip: which side is the cephalic prominence , degree of descent

15. Cardinal movements of Labor
■ Positional changes in the presenting part required to
navigate the pelvic canal
– Engagement
– Descent
– Flexion
– Internal Rotation
– Extension
– External Rotation
– Expulsion

16. Engagement
■ BPD passes thru the pelvic inlet
– NP: engagement happens
before labor begins
– MP: engagement and
descent happens at the
same time
■ Fetal head enters the inlet
transversely / obliquely

17. Descent
■ First requisite for birth of NB
■ 4 forces
– Pressure of AF
– Pressure of fundal
contraction
– Bearing down efforts of the
mother
– Extension and straightening
of fetal body

18. ■ ASYNCLITISM
– Lateral deflection of
fetal head to a more
posterior or anterior
position
■ Successive fetal head
shifting from
posterior to anterior
asynclitism aids
descent

19. Flexion
■ Head meets
resistance
■ OFD to SOB

20. Internal Rotation
■ Turns occiput away from
transverse axis
■ Usually, occiput rotates
anteriorly towards
symphysis pubis
■ If head fails to turn
– MP: rotates after 1-2
contractions
– NP: 3-5 contractions

21. Extension
■ Fetal head reaches the
vulva
■ 2 opposing forces:
– Anterior: resistance of
pelvic floor and
symphysis pubis
– Posterior: uterus (fundal
contraction)

22. External Rotation
■ Restitution
■ If occiput is originally
directed towards the L, it
rotates towards the L
■ Serves to bring the
bisacromial diameter into
relation to AP diameter

23. Expulsion
■ Anterior shoulder appears
under symphysis pubis
■ Perineum becomes
distended by the posterior
shoulder
■ After delivery of shoulders,
the rest of the body quickly
passes

24. Normal Labor
■ Uterine contractions that bring
about demonstrable effacement
and dilatation of the cervix

25. Functional Division of Labor

26. Stages of Labor

27. First stage of Labor
■ From regular uterine
contractions to full cervical
dilatation
■ Latent phase (onset of UC to
3-4cm)
– NP: 20hrs
– MP: 14hrs
■ Cervical dilatation
– NP: 1.2 cm/hr
– MP 1.5 cm/hr

28. Second stage of Labor
■ Full cervical dilatation to
delivery of the baby
– NP: 50 minutes
– MP: 20 minutes
■ Become abnormally long
– A contracted pelvis
– A large fetus
– Impaired expulsive effort
from conduction
analgesia or intense
sedation

29. Second stage of Labor
■ Maternal expulsive efforts
– Bearing down: reflex and spontaneous but,
does not employ expulsive force and
coaching is desirable
– Leg: half-flexed
– Deep breath & breath held
– Exert downward pressure
– She should not be encouraged to “push”
beyond the time of completion of each
uterine contraction

30. Preparation for the delivery
■ The dorsal lithotomy position
– Increase the diameter of the pelvic outlet
– Using leg holder and stirrup -> result in
spontaneous tear or fourth degree
■ Not to separate the legs too widely or place
one leg higher than the other
– Will exert pulling forces on the perineum
leading to extension of a spontaneous tear
or an episiotomy into a 4th degree
laceration.

31. Preparation for the delivery
■ The legs may cramp in part, because of
pressure by the fetal head on nerves in the
pelvis.
– relieved by changing the position of the leg
or by brief massage
■ Vulvar and perineal cleansing: sterile drape and
gowning, gloving

32. Delivery of the head
■ Crowning: encirclement of the
largest head diameter by the vulvar
ring
■ Unless episiotomy; spontaneous
laceration
■ It is now clear that an episiotomy will
increase the risk of a tear into the
external anal sphincter and the
rectum
■ unless episiotomy. anterior tears
involving the urethra and labia are
mush more common

33. Delivery of the head
Ritgen maneuver
■ When the head distends the vulva
and perineum enough to open the
vaginal introitus to a diameter of 5
cm or more
■ One hand: a towel-draped, gloved
hand may be exert forward pressure
on the chin of the fetus through the
perineum just in front if the coccyx
■ The other hand: exerts pressure
superiorly against the occiput

34. Delivery of the shoulder
■ External rotation: bisacromial
diameter had rotated into the
anteroposterior diameter of the pelvis
■ Downward traction : ant. shoulder
under the pubis
■ Upward movement: post. shoulder is
delivered

35. Clamping of the cord
■ Between two clamps: 2 cm and 5cm
■ Delay for up to 60sec
– Increases total iron stores
– Expand blood volume
– Decrease anemia incidence in neonates

36. Third stage of Labor
■ After delivery of the infant, the
height of fundus and its
consistency are ascertained
■ Fundus is frequently palpated to
make certain that the organ
does not become atonic and
filled with blood from placental
separation

37. Signs of placental separation
■ uterus becomes globular
■ sudden gush of blood.
■ uterus rises in the abdomen
■ Lengthening of umbilical
cord
– ** Usually within 5 min,
sometimes within 1min

38. Delivery of the Placenta
■ Traction in the umbilical cord
must not be used to pull the
placenta out of the uterus
■ The uterus is lifted cephalad
with the abdominal hand.This
maneuver was stopped as the
placenta passes through the
introitus
■ If the membranes start to tear,
they are grasped with a clamp
and removed by gentle traction

39. Delivery of the Placenta
■ Manual removal of placenta
– The placenta will not
separate promptly (preterm)
– There is brisk bleeding and
the placenta cannot be
delivered -> manual removal

40. Lacerations of the Birth Canal
Degree Covered
First-degree: fourchette, perineal skin, vaginal
mucosal membrane
Second-
degree:
fascia and muscle of the perineal
body
usually extend upward on one or
both sides of the vagina
Third-
degree:
involve the anal sphincter
Fourth-
degree:
rectal mucosa
expose the lumen of the rectum
involve the region of the urethra

41. Episiotomy and Repair
■ Purpose of episiotomy
– Easier to repair
■ Postoperative pain is less
■ Healing improved
– Prevented pelvic relaxation (cystocele, rectocele, urinary
incontinence)
– But, increased incidence of anal sphincter and rectal tears

43. ■ Timing of the repair of episiotomy
– After the placenta has been delivered
■ Technique
– Hemostasis and anatomical restoration without excessive
suturing are essential
– Suture material: 3-0 chromic catgut

44. ■ Fourth-degree laceration
– approximate the torn edges of
the rectal mucosa with
muscularis sutures placed
approximately 0.5 cm apart
– this muscular layer then is
covered with a layer of fascia
– stool softener, prophylactic
antimicrobials
– enema should be avoided