Instrumental delivery

instrumental delivery in modern obstetrics

2. Introduction
The developments in the fields of anaesthesia, antibiotics, blood
transfusion, surgical aids & techniques have made "caesarean
section ", very safe operation.
In view of these developments, the expectations of all
concerned - patient, relatives, attending doctors & authorities
including legal system has undergone a marked change so that
a small error will be viewed seriously.

3. In such a scenario, the practicing obstetrician
of today is likely to have reservations about
using instrumental deliveries of unpredictable
course & outcome.
Instrumental deliveries are becoming rarer
and rarer.
 In the last two decades, not only very few
developments have taken place in this field,
many of the instrumental deliveries have
become obsolete.

4. Indication
Maternal diseases
Maternal distress
Fetal distress
Prolonged 2
nd
stage

5. EFFECTS OF REGIONAL ANALGESIA ON
INSTRUMENTAL DELIVERY
Epidural analgesia is widely accepted as causative in
failure of spontaneous rotation to occiput anterior
position, as well as in slowing second-stage labor and
decreasing maternal expulsive efforts.
Its use has been associated with increases in forceps
delivery & vacuum extraction.
(Ploeckinger and associates, 1995; Sizer and Nirmal, 2000).

6. FORCEPS
WILLIAM CHAMBERLAIN Secret
in 1569
practiced forceps delivery as a family secret in
Southampton. This was kept as a family secret for
over 100yrs and four generations.

7. Pelvic Curve = Wrigley
No Pelvic Curve = Simpson

9. Pernial curve , only in Piper`s Forceps

11. Function
Traction: -This is the most important function. Pull
required in a primigravida is 18 kgs & in a multipara it
is 13 kgs.
Compression effect: -This is minimal when properly
applied & should not be more than necessary to grasp
the head.
Rotation of head: -This occurs with the use of
Kejilland's forceps and also in low forceps cephalic
application with the occiput in the 2 or 10 'o' clock
position.
Protective cage: - When applied on a premature baby
it protects from the pressure of the birth canal.
Caesarean section.

12. Classical (old) Classification
Low/outlet forceps (no distinction): - forceps applied
when the foetal head/skull has reached the pelvic floor,
sagital suture has reached the A- P diameter of pelvis
and scalp is visible without separating the vulva.
Mid forceps: - forceps applied when head is engaged
but criteria for low forceps not reached.
 High forceps: - forceps applied when head is not
engaged.

13. New classification
(ACOG,1989)
Outlet forcepsFoetal scalp is visible without separating the vulva
Sagital suture is in the A.P.diameter.
Fetal head on the perineum
low forceps The leading point of the skull at station +2
Rotation ≤ 45 degree.
Mid forceps Station above +2 but head is engaged.
High forcepsEXCLUDED

14. Application
Cephalic application -.
Blades are applied along the sides of the head, grasping
the bi-parietal diameter in between the widest part of the
blades and the long axis of the blades correspond to the
occiputo-mental plane.
Pelvic application: -.
Blades are applied on the lateral pelvic wall ignoring the
position of the head if the head is not rotated. Serious
compression effect on the cranium can occur, so it should
be avoided.
When the head is sufficiently rotated, pelvic & cephalic
applications naturally coincide and so pelvic application is
only justified in low forceps operations.

15. vacuum
Malstrom designed the stainless steel
vacuum cup in the 1950s and this
revolutionized the practice of operative
vaginal delivery..
 In the U.S. the stainless steel cups have
almost completely been replaced by plastic
and Silastic soft cup extractors

16. There have been arguments about the relative
success rates and trauma incidence of the different
vacuum extractor models. The soft cups are
significantly more likely to fail to achieve vaginal
delivery However, the soft cups were associated with
less scalp injury .
 metal cups appear to be more suitable for
“occipitoposterior,” transverse, and difficult
“occipitoanterior” position deliveries. The soft cups
seem to be more appropriate for straightforward
deliveries.
Johanson and Menon, 2001.

18. Advisory Letter
In 1998 the U.S. Food and Drug
Administration (FDA) released an advisory
letter to alert individuals who use vacuum
extractors and inform them that these devices
may cause serious or fatal complications
The vacuum extractor should only be used
when a specific indication exists.
The operator should be aware of indications,
contraindications, and precautions.

19. The operator should follow manufacturers'
recommendations regarding cup placement,
vacuum strength, cumulative duration of
applications, and number of extraction attempts.
Rocking movements should not be applied to the
device and only steady.
Neonatal care providers should be alerted that a
vacuum has been used.
Neonatal staff should be educated about the specific
complications associated with vacuum devices.

20. Advantages of vacuum over forceps
Less maternal complication
Need less experience.
Not occupying space.
Autorotation occur during traction.

21. Disadvantages
More fetal complications.
Not suitable for
Preterm labour.
Dead fetus.
Face presentation.

22. Complication
are mostly due to faulty technique rather than the
instrument.
Maternal
Injury
Vaginal lacerations, cervical tear & rupture uterus .
Injury of the bladder.
Extension of the episiotomy involving anus & rectum or
vaginal vault.
Post partum haemorrhage
Due to trauma, Atonic uterus or Anaesthetisia.

23. Shock –.
Due to blood loss, dehydration or prolonged labour.
Sepsis –.
Due to improper asepsis or devitalisation of local
tissues.
Anaesthetic hazards.
Delayed or long-term sequel –.
Chronic low backache, genital prolapse & stress
incontinence.

24. Fetal-
Asphyxia.
Trauma-
Intracranial haemorrhage.
Cephalic haematoma.
Facial / Brachial palsy.
Injury to the soft tissues of face & forehead.
Skull fracture
Remote-cerebral palsy.
Foetal death-around 2%.

25. Intracranial haemorrhage
1:334 failed vacuum extraction or forceps followed by cesarean
section
1:860 after vacuum extraction
1:664 after forceps
1:907 after cesarean section during labor
1:2,750 after cesarean section without labor
1:1,900 normal spontaneous vaginal delivery.
Towner D et al 1999.

26. Safe practice: prerequisites for Safe practice: prerequisites for
instrumental deliveryinstrumental delivery

FFully dilated cervixully dilated cervix

OOne-fifth or nil palpable abdominallyne-fifth or nil palpable abdominally

RRuptured membranesuptured membranes

CContractions presentontractions present

EEmpty bladdermpty bladder

PPresentation and position knownresentation and position known

SSatisfactory analgesiaatisfactory analgesia

28. Safe practice: recognise Safe practice: recognise
conditions predictive of conditions predictive of
difficulty/failuredifficulty/failure
1/5 palpable 1/5 palpable
Station 0Station 0
OP positionOP position
Moulding ++/+++Moulding ++/+++
Slow progressSlow progress
Big babyBig baby
BMI > 30BMI > 30

29. Examples of error in Examples of error in
instrumental deliveryinstrumental delivery

Abdominal palpation not doneAbdominal palpation not done

Prolonged tractionProlonged traction

Continuous tractionContinuous traction

Rotation during a contractionRotation during a contraction

Traction directed forwards and upwards too Traction directed forwards and upwards too
soonsoon

30. is the healthiest
possible
outcome for
mother and baby.