FORCEPS DELIVERY
Obstetrical forceps are
designed for extraction of the fetus. True forceps were first devised in the
late 16th and beginning of the 17th century
Forceps
Obstetrical forceps is
a pair of instruments specially designed to assist extraction of the fetal head
and there by accomplishing delivery of the fetus.
History
The
obstetrical forceps, allowing during birth, the extraction of a living child,
was invented by the eldest son of the Chamberlen family of surgeons. The
Chamberlens were French Huguenots working in Paris before they immigrated to
England in 1569 to flee from religious violence perpetrated in
France. William Chamberlen, the patriarch of the family, was most likely a
surgeon; he had two sons, whom he both named Pierre, that became maverick
surgeons that specialized in midwifery. William and the eldest son
practiced in Southampton and then settled in London. The inventor was probably
the eldest Pierre (then
Peter in England), who became obstetrician-surgeon of Queen Henriette,
wife of King Charles I of England and daughter of Henry IV, King of France. The
forceps were used most notably in hard and difficult childbirths, ones which
would most probably result in the death of the baby, because in other
situations hooks or other instruments that would endanger the life of the
infant were used. In the interest of secrecy, the forceps were carried into the
birthing room in a lined box and would only be used once everyone was out of
the room and the mother blindfolded. He was succeeded by his nephew, Dr.
Peter Chamberlen (also known as Peter the Third), as royal obstetrician. The
success of this dynasty of obstetricians with the Royal family and high nobles
was related in part to the use of a "secret" instrument allowing
release of live child in difficult cases.
The
instrument was kept secret for a 150 years by the Chamberlen family, although
there is evidence for its presence of as far back as 1634. Hughes Chamberlen,
Grand nephew of Peter the eldest, tried to sell the instrument in Paris
in 1670, but the demonstration he did in front of François Mauriceau,
responsible for Paris Hotel-Dieu maternity,
was a resounding failure which resulted in the death of child and mother. The
secret may have been sold by Hughes Chamberlen to Dutch obstetricians at the
start of the 18th century in Amsterdam, but there are doubts about the
authenticity of what was actually provided to buyers.
Models
derived from the Chamberlen instrument finally appeared gradually in England
and Scotland in 1735. About 100 years after the invention of the forceps by
Peter Chamberlen Sr. a surgeon by the name of Jean Palfyn presented
his obstetric forceps to the Paris Academy of Sciences in 1723. They
contained parallel blades and were called the Hands of Palfyn, which were
possibly the instruments described by used in Paris by Gregoire father and son,
Dussée and Jacques Mesnard.
In
1813, Peter Chamberlen’s midwifery tools were discovered at Woodham Mortimer
Hall. In the attic of the house, the instruments were found along with gloves,
old coins and trinkets. The tools discovered also contained a pair of
forceps that were presumably invented by the father of Peter Chamberlen,
assumed so because of the barbaric nature of the design.
The
Chamberlen family's forceps were based on the idea of separating the two
branches of sugar clamp, which were put in place one after another in the birth
canal. This was not possible with conventional tweezers previously tested.
However, they could only succeed in maternal pelvis of normal dimensions and on
fetal heads already well engaged (i.e. well lowered into maternal pelvis).
Abnormalities of pelvis were much more common in the past than today, which
complicated the use of Chamberlen forceps. The absence of pelvic curvature of
the branches (vertical curvature to accommodate the anatomical curvature of
maternal sacrum) prohibited blades from reaching upper-part of the pelvis and
exercising traction in the natural axis of pelvic excavation.
In 1747 French
obstetrician Andre Levret,
published "Observations sur les causes et accidents de plusieurs
accouchements laborieux" (Observations on the Causes and Accidents of
Several Hard Deliveries), in which he modified the instrument to follow the
curvature of the maternal pelvis, allowing a grip on a fetal head still high in
the pelvic excavation, which could assist in more difficult cases. This
improvement was published in 1751 in England by William Smellie in
the book " A Treatise on the theory and practice of midwifery." After
this fundamental improvement, the forceps would become a common obstetrical
instrument for more than two centuries.
The
last improvement of the instrument was added in 1877 by a
French obstetrician, Stephan Tarnier in "descriptions of
two new forceps." This instrument featured a traction systemmisaligned
with the instrument itself, sometimes called the "third curvature of the
forceps". This particularly ingenious traction system, allowed the forceps
to exercise traction on the head of the child following the axis of the
maternal pelvic excavation, which had never been possible before. Tarnier's
idea was to "split" mechanically the grabbing of the fetal head
(between the forceps blades) on which the operator does not intervene after
their correct positioning, from a mechanical accessory set on the forceps
itself, the "tractor" on which the operator exercises traction needed
to pull down the fetal head in the correct axis of the pelvic excavation.
Tarnier forceps (and its multiple derivatives under other names) remained the
most widely used system in the world until the development of the cesarean section.
Forceps
had a profound influence on obstetrics as it allowed for the speedy delivery of
the baby in cases of difficult or obstructed labor.
Over the course of the 19th Century, many practitioners attempted to redesign
the forceps, so much so that the Royal College of Obstetrics and Gynecologist
collection has several hundred examples. In the last decades, however, with the
ability to perform a cesarean section relatively safely, and the
introduction of the ventouse or vacuum extractor, the use of forceps and
training in the technique of its use has sharply declined.
Types of forceps
Eversince either peter
1 and peter 2 of the Chamberien family
invented the forceps around A.D1600 , many designed were invented or modified.
But only three varieties are commonly used in present day obstetric practice.
These are
- Long
curvedforceps with or without axis traction device
- Short
curved forceps
- Kielland’s forceps
Design of forceps
Forceps vary
considerably in size and shape, but basically consist of two crossing branches.
Each branch has four components,
The blade
The shank
Lock
Handle .
Each blade has two
curves , the cephalic and pelvic. The cephalic curve conforms to the shape of
the fetal head, and the pelvic curve with that of the birth canal.
The cephalic curve
should be larger enough to grasp the fetal head firmly with out compression .
the pelvic curve corresponds more or less to the axis of the birth canal but
varies considerably among different instruments. The blades are connected to
the handle by the shanks, which gives the requisites length to the instrument.
The kind of
articulation or forceps lock varies among different instruments. The common
method of articulation consist of a socket located on the shank at the junction
with the handle , in to which fits a socket similarly located on the opposite
shank. This forms of articulation is commonly referred to as the English lock.
A sliding lock is used in some forceps , such as Kielland forceps and allow the
shank to move forward and backward independently. In some cases, the operator
chooses to use an axis traction device help to maintain the appropriate vector
for a necessary delivery.
Indication for forceps delivery
- Delay
in second stage of labour due to
minor degree of cephalopelvic disproportion , persistent occipito
posterior position , deep transverse arrest or secondary uterine inertia.
- Foetal
distress in the secondary stage of labour when the fetal head is engaged.
- Prolapsed
of the umbilical cord in the second stage of labour when the head is
engaged.
- In
the delivery of the after coming head in the breech presentation
- Maternal
distress in the second stage of labour.
- Prophylaxis
in maternal conditions such as
a.
Cardiac disease
b.
Hypertension
c.
Preeclampsia and
eclampsia
d.
Diabetes
e.
Chronic
nephritis
f.
Pulmonary
tuberculosis
g.
Prophylaxis in
premature infants .
Choice of forceps operations /delivery
Mid forceps (10%)
It is used when head
(station )is at or near the level of ischial spine. Internal rotation of the
head is often incomplete. Manual rotation may be is needed before traction.
Low forceps (90%)
The head is near the
pelvic floor or even visible at the introitus. It is commonly used now a days
with advantages.
Outlet forceps
It is a variety of low
forceps where the head is on the perineum. Thus , all outlet forceps are low
forceps but not all the forceps are outlet forceps operations.
Types of application of blades
Cephalic application
The blades are applied
along the sides of the head grasping the biparital diameter in between the
widest part of the blades. The long axis of the blade corresponds more or less
to the occipito – mental plane of the fetal head. It is the ideal method of
application as it has got a negligible compression effect on the cranium
Pelvic application
When the blades of the
forceps are applied on the lateral pelvic walls ignoring the position of the
head , it is called pelvic application. If the head remains unrotated , this
types of application puts serious compression effect on the cranium and thus
must be avoided.
Functions of forceps
¨
Traction is the
most important function of the forceps. In primigravidae , the pull required is
estimated to about 18kg and that in multiparae about 13kg.
¨
Its compression
effects on the cranium should be minimal when correctly applied over the
biparital plaine and should not be more than required to grasp the fetal head.
¨
Rotation of the
head can be achieved by Kielland forceps.
However in the low forceps operation with the sagital sutures placed obliquely
, with the occiput placed say at 2 or 10 ‘o’ clock position . cephalic
application of the blades of ordinary forceps and traction causes rotation of
the sagital suture. So as to bring it in an antero- posterior diameter of he
outlet.
¨
To provide a
protective cage for the head from the pressure
of the birth canal as in premature baby or to control the delivery of
the after coming head to lesson the dangers of sudden decompression.
¨
One forceps
blade may be used as a vectis to assist delivery of the head in caesarian
section.
Criteria to be fulfilled prior to forceps operation
- Fetal
and utero placental criteria
The
fetal head must be engaged
The
cervix must be fully dilated
The
membranes must be ruptured
The
position and station of the fetal head must be known with certainty .
- Maternal
criteria
No
major cephalo-pelvic disproportion by clinical pelvimetry
Bladder
must be emptied
Adequate
analgesia .
- Others
Experienced
operators
Verbal
or written consent
Mnemonic for
F-O-R-C-E-P-S
F :- Favorable head
position and station
O :- Open os ( fully
dilated )
R :- Ruptured membranes
C :- contraction
present and consent
E :- Engaged head empty
bladder
P :- pelvimetry no
major CPD
S :- Stirrup, lithotomy position
Classification of forceps delivery according to
station and rotation
- High
forceps
Head
is not engaged . this types is not included in classification
- Mid
forceps
Head
is engaged in the pelvis but presenting part is above +2 station .
- Low
forceps
Leading
point of the fetal skull is + 2 or more but has not get reached th pelvic floor
(1) rotation is <45 ̊ (2) rotation is >45 ̊
- Outlet
forceps
¨
Scalp is visible
at the introitus without separating the labia
¨
Fetal skull has
reached the level of the pelvic floor
¨
Sagital sutures
is in direct anterior posterior diameter
¨
Fetal head is at
or on the perineum
¨
Rotation is
<45 ̊
LOW
FORCEPS DELIVERY
Low forceps delivery is the delivery of the fetal
head which has descented below the level of the ischial spine . an episiotomy
is done before the delivery is carried out
Preparation
of the patient for forceps delivery
Indication
Maternal and foetal distress in the second stage of
labour.
Types
of forceps
Wrigley’s forceps is used for low forceps delivery .
Anesthesia
Pudentral block is supplemented by perineal and
labial infilteration with 1% lignocain hydrochloride is quite effective in
producing local anesthesia .
Catheterization
Internal examination to assess
- state of
the cervix
- membranous status
- Presentation
and position of the head
- Assessment
of the pelvic outlet
Episiotomy :- it may be done during traction when
the perineum becomes bulged and thinned out by the advancing head.
Steps of forceps delivery
The operation consist of the following steps
® Identification
of the blades and their application
® Locking
of the blades
Step 1 identification and application of the blade
Step 2 locking of the blade
Step 3 and 4 traction and removal of the blades
Step
1 identification and application of the
blades
The identification of the blades is to be made after
articulation as mentioned earlier. The left or lower blade is to be introduced
first. The four fingers of the semi supinated right hand are inserted along the
left lateral vaginal wall , the palmar surface of the fingers rest against the
side of the head. The fingers are to guide during application and to protect
the vaginal wall. The handle of the left blade during application and to
protect the vaginal wall. The handle of the left blade is taken lightly by
three fingers of the left hand . index , middle and thumb in a pen holding
manner and is held vertically almost parallel to the right inguinal ligament
The fenestrated portion of the blade is placed on
the right palm with the tip pointing upwards . the right thumb is placed at the
junction of the blade and the shank .
The blade is introduced between the guiding inernal
fingers and the fetal head manipulated by the thumb . as a blade is pushed up
and up , the handle is carried downwards and backwards , traversing wide arc of
a circle towards the left until the shank is to lie straight on the perineum.
Utmost gentleness is required while introducing the blade . no assistant is
usually required to hold the handle in low forceps operation . when correctly
applied the blade should be in contact with the perineum and the superior
surface of the handle should be directed upwards.
Introduction
of the right blade
The two fingers of the left hand are now introduced
in to the right lateral wall of the vagina along side the babies head. The
right blade is introduced in the same manner as with left one but holding it
with the right hand.
Step
2 locking of the blades
When correctly applied , the blade should be
articulated with ease. Minor difficulty in locking can be corrected by
depressing the handle on the perineum. In case of major difficulty the blades
are to be removed , the cause are to be sought for (vide infra ) and the blades are to be reinserted. The handle
should never be forced to lock them
Step
3 and 4 traction and removal of blade
Before traction is applied , correct application of
the blade to be ensured. Correct application is evidenced by
- easy
locking
- the blades
are equidistant from the lambdoid suture
- firm
gripping of the head on the bipolar diameter – as judged by a few
tentative pulls.
Principles
Steady but intermittent traction should be given if
possible during contraction. However in outlet forceps the pull may be
continuous. Strong traction is not needed as the only resistance to overcome is
the perineum and the coccyx .
Gripping of the articulated forceps during traction
The traction is given by gripping the handle,
placing the middle finger in between the shanks with the ring and index fingers
on either side on the finger guard. During the final stage of traction , the
four fingers are placed in between the shanks and the thumb which is placed on
the under surface of the handles exerts the necessary force.
Direction of the pull
The direction of the pull corresponds to the axis of
the birth canal. In low forceps operation depending upon the station of the
head , the direction of the pull is downwards and backwards until the head
comes to the perineum. The pull is then directed horizontally straight towards
the operator till the head is almost crowned. The direction of pull is
gradually changed to upwards and forwards , towards the mothers abdomen to
deliver the head by extension. The blades are removed one after the other , the
right one first .
Following the birth of the head , usual procedures
are to be taken as in normal delivery. Routine intravenous methergin 0.2 mg is to
be administered with the delivery of the anterior shoulder. Episiotomy is repaired in the usual method .
laceration on the vaginal walls or perineum are to be excluded .
OUTLET FORCEPS OPERATIONS
Wrigley’s forceps are used exclusively in outlet
forceps operations . perineal and vulval infiltration with 1% lignocain is
enough for local anesthesia . the blades are introduced as in the low forceps
operations with long curved forceps except the two fingers are to be introduced
into the vagina for the application of the left blade. Traction is given
holding the articulated forceps with the fingers placed in between the shank
and the thumb on the under surface of the handle. The direction of the pull is
straight horizontal and then upward and forwards.
MID
FORCEPS OPERATIONS
The commonest indication of the midforceps operation
is following manual rotation of the head in malrotated occipito –posterior
position. The commonly used forceps is long curved one with or without axis
traction device. Kiellands is useful in the hands of an experts.
Procedures
General anesthesia is preferable
- Introduction
of the blades :- the introduction of the blades is
to be done after prior correction of the malrotation .
a. without
axis traction device – the blades are introduced as in the low forceps
operations. An assistant is required to hold the left handle after its
introduction
b. with
axis traction device – while applying the left blade, the traction rod already
attached to the blade is held backwards. During introduction of the right blade
the traction –rod must be held forwards otherwise it will prevent locking of
the blades.
- Traction
a. with
out axis traction device – The direction of pull is first downwards and
backwards then and finally upwards and forwards.
b. With
axis traction device – the traction handle is to be attached to the traction
rods. During traction, the traction rod
should remain parallel with the shanks. When the base of the occiput
comes under the symphysis pubis , the traction rods are to be removed.
Difficulties in forceps delivery
The difficulties are encountered mainly due to
faulty assessment of the case before the operative delivery is undertaken.
However there is hardly any difficulty in low forceps operation.
During
application of the blades – The causes are
® Incompletely
dilated cervix
® Unrotated
or non-engaged head
Difficulties
in locking – The causes are
® Application
in unrotated head
® Improper
insertion of the blade
® Failure
to depress the handle against the perineum
® Entanglement
of the cord or fetal parts inside the blades.
Difficulty in traction –The causes of failure to deliver
with traction are
1. Undiagnosed
occipito – posterior position
2. Faulty
cephalic application
3. Wrong
direction of traction
4. Mild
pelvic contraction
5. Constriction
ring
Slipping
of the blades - The causes are
- The blades
are not introduces far enough
- Faulty
application in occipito posterior position. The blades should be
equidistant from the sinciput and occiput.
Complication of forceps delivery
Maternal
Immediate
¨ Injury
–
® vaginal
laceration or sulcus tear,
® cervical
tear ,
® extention
of episiotomy to involve the vaginal vault ,
® complete
perineal tear.
¨ Nerve
injury :- femoral (L2, 3, 4 )
® Lumbosacral
trunk (L4, 5) with mid forceps delivery
¨ Postpartum
hemorrhage may be
- Traumatic
- Atonic
requiring blood transfusion
- Both may
cause shock
Anesthetic
complications
Purperial sepsis and maternal morbidity
Remote
® Painful
perineal scars
® Dyspareunia
® Lowback
ache
® Genital
prolapse
® Stress
urinary incontinence
® Sphincter dysfunction
Fetal
Ø Immediate
Ø Asphyxia
Ø Facial
brusing
Ø Intracranial
hemorrhage
Ø Cephal
hematoma
Ø Facial
palsy
Ø Skull
fracture
Ø Cervical
spine injury
Remote
Cerebral or spastic palsy due to residua cerebral
injury
Nursing diagnosis
- Alteration
in comfort due to pain related to delivery process
® Assess
the types of pain ,types , duration and intensity
® Provide
comfortable left lateral position to the
mother
® Provide
psychological reassurance to the mother
- Potential
for complication related to forceps application
® Assess
for any types of laceration
® Maintain
aseptic technique
® Handle
the case carefully
® Case
should handle by experts
® Clean
the perineal area with betadine
- Potential
for infection related to forceps
application
® Assess
for any scar
® Maintain
strict aseptic technique
® Clean
the surrounding
® Avoid
many visitors
- Fear and anxiety of parents related to delivery process
®
Provide proper explanation about
babies condition
®
Give information about progress of
delivery frequently
®
Provide psychological reassurance to
the mother
®
Clarify the mother doubts
