2. DEFINITION:
• Forcep is an instrument applied to extract a live term fetus by the head out of
the birth canal.
OR,
• Forcep is an instrument for grasping, holding firmly, or exerting traction upon
objects especially for delicate operations
3. CONSTRUCTION OF FORCEPS :
• Forceps consist of two symmetrical parts, branches that can differ in the structure of the
left and right parts of the lock.
• The branch grasped by the left hand and introduced into the left part of
maternal pelvis is called the left branch; the other one is the right branch.
• Each branch has three parts:
1) The blade
2) The lock and,
3) The handle.
4.
5. BLADE:
• The blade is a curved plate with a wide cut-away (fenestration).
• Curved edges of the blade are referred to as borders (upper and lower one).
• The blade can be of varying shape to conform to the shape of fetal head or
maternal pelvis.
• The cephalic curve is the convolution of the blade in the frontal plane replicating
the shape of fetal head.
• The pelvic curve is convolution of the blade in the sagittal plane conforming to
the shape of sacral fossa and, to a certain extent, the axis pelvis.
• If forceps have blades without a pelvic curve, they are referred to as straight
forceps (Lazarevitch, Kielland forceps).
6. LOCK :
• The lock joins the forceps branches. Locks of various forceps models have different
structures.
• The distinctive feature is the degree of mobility that the lock allows in the
branches:
1. Russian forceps (Lazarevitch): the lock slides freely;
2. English forceps (Smellie): the lock is moderately mobile;
3. German forceps (Naegele): the lock is almost immovable;
4. French forceps (Levret): the lock is fixed.
7. HANDLE :
• The handle is for holding the forceps and applying traction.
• It has smooth inner surfaces, so when the branches are locked, the surfaces adhere
tightly.
• The outer surface of handles are scalloped which prevents the operator’s hands
from slipping when applying traction.
• The handle is made hollow so that the instrument is not so heavy.
• The upper parts of handles have lateral protrusions called Busch’s hooks.
• When performing traction they provide support to the operator’s hands. Besides,
Busch’s hooks can indicate inadequate position of forceps if upon closing the
branches the hooks are not opposite each other.
8. CLASSIFICATION OF FORCEPS:
• Depending on where the fetal head is in the pelvis there are the following variants:
1) Outlet forceps
2) Low/mid forceps
3) Rotational forceps
9. OUTLET FORCPES:
• Outlet forceps are the type of forceps applied to the head stationed in pelvic outlet
with its sagittal suture in the anteroposterior diameter.
• The internal head rotation has been accomplished.
• The head is at the pelvic floor, the entire sacral fossa as well as the coccygeal area is
filled by the head, ischial spines cannot be reached. The sagittal suture is in the
anteroposterior outlet diameter.
• The posterior fontanelle is palpated below the anterior one (head flexed - occipital
presentation) and placed anteriorly (anterior position) or posteriorly (posterior
position).
• The blades are inserted following the rules described above, in transverse outlet
diameter. Forceps handles are placed parallel to each other
11. LOW/MID FORCEPS:
• Low/mid forceps are applied to a head stationed with its sagittal suture in one of
oblique pelvic diameters (pelvic greatest or least dimension).This type is also
referred to as atypical.
• Obstetric forceps are applied in the opposite oblique diameter so that the blades
grasp the head at the site of parietal tubers.
• When low/mid forceps are applied, the sequence of inserting the blades remains
the same.
• First ,the left blade is inserted, then the right one. However, insertion of blades has
its specifics depending on fetal position and whether it is left or right. Thus in left
occipitoposterior position the left blade is inserted, under the guidance of the right
hand,to the left and somewhat backwards (to the posterolateral pelvic part).
13. • The blade is positioned on the area of left parietal tuber.This blade is referred to as
fixed as it is positioned accurately immediately upon insertion.
• The right blade is inserted to the right pelvic part by the conventional method,and
then, guided by the left hand, it is introduced into the vagina; the blade moves
forward until it reaches the right parietal tuber.
• The blade is moved by carefully pressing on its inferior border with the second
finger on the left hand. In this situation the right blade is referred to as wandering.In
the end both blades are placed opposite each other in the left oblique pelvic
diameter.
14. INDICATIONS :
• Forceps delivery is indicated in case of maternal or fetal danger during the
expulsion stage that can be eliminated totally or partially by a fast termination of
labor.
• Indications for forceps delivery can be conventionally divided into two groups:
1) Maternal and
2) Fetal indications.
15. • Maternal Indications : Can be those related to pregnancy and labor.
• severe PE,
• persistent uterine inertia,
• weak pushing,
• hemorrhage in the second stage,
• endometritis in labor and ,
• Can be those related to the patient’s extragenital disease requiring elimination of
pushing- somatic indications
• decompensated cardiovascular conditions
• respiratory disorder due to pulmonary disease,
• high degree myopia,
• acute infection
• severe mental disorder
• intoxication or poisoning
• Fetal Indications: acute fetal hypoxia in the expulsion stage.
16. PREREQUISITES :
• Certain conditions should be met; if even one of the prerequisites is absent, forceps
delivery is contraindicated.
• The prerequisites are as follows:
1. live fetus
2. full cervical dilation
3. membranes must be ruptured
4. no disproportion between the size of the head and the size of the pelvis;
5. fetal head should be in the pelvic outlet with sagittal suture in the anteroposterior
diameter, or in pelvic cavity with its sagittal suture in one of oblique diameters.
17. PREPARATION:
Preparation for forceps delivery includes several aspects:
• choice of analgesia;
• preparation of the patient;
• preparation of the obstetrician;
• vaginal examination;
• testing the forceps.
For forceps delivery the patient should be in lithotomy position.
The bladder must be empty.
External genitals and inner thighs are swabbed with antiseptic.
18. TECHNIQUES OF FORCEPS APPLICATION :
STEP 1:
• Forceps are inserted using the first «treble rule» (three on the right, three on the left.
• The left blade is taken by the left hand and applied on the left side of maternal
pelvis controlled by the right hand;
• The right blade is taken by the right hand and applied on the right side of
maternal pelvis controlled by the left hand.
• To control the position of the left blade the obstetrician inserts a half-hand, that is,
four fingers of the right hand, except for the first one.
• The palmar surface should face the head; it is introduced between the head and left
lateral pelvic wall. The right thumb remains outside, it is drawn aside.
• After inserting the half-hand one begins applying the left blade.
• The handle is grasped the way one holds a pen or fiddlestick. This special way of
holding the blade helps to avoid application of force when the blade is inserted.
19.
20. • Before inserting the handle into the birth canal one draws the handle aside and
positions it parallel to the opposite inguinal fold, and vice versa.
• The blade’s toe (tip) is placed on the palm of the half-hand inserted into the vagina.
The posterior border of the blade is placed on the lateral surface of the IV finger
and rests against the drawn-aside thumb.
• The blade should slip inside the birth canal under the impact of its own weight and
due to the right thumb nudging the inferior border of the blade.
• The handle end should move in an arch. As the blade moves in, the handle is
brought down and assumes a horizontal position.
21. • The half hand inserted into the birth canal acts as a guide; it controls the accurate
direction and position of the blade. Using this half-hand the obstetrician ensures
that the blade’s toe is not aimed at the fornix or lateral vaginal wall and does not
graze the edge of cervix.
• Once the first blade is inserted, it is passed over to the assistant so as to avid
shifting it.
• The other (right) blade is inserted using the same technique and observing the “
treble rule”the right blade is taken by the right hand, applied on the right side of
maternal pelvis controlled by the left half-hand.
22. Step 2 of the procedure is locking the forceps.
• If the blades are positioned asymmetrically and it takes a certain effort to lock
them, it means that their position is inaccurate.
• The forceps should be drawn out and reapplied.
Step 3 of procedure is tentative traction.
• This indispensable step ensures that the forceps are applied accurately and are not
likely to slip.
• With his right hand the obstetrician grips the handle from above so that the index
and middle fingers are on the Busch’s hooks.
• The left hand is applied to the dorsal surface of the right hand, stretches the index
or middle fi nger and touches the head at the point of direction area.If the forceps
are accurately placed, the fingertip keeps the contact with the head during the
entire tentative traction. If it lets go ofmm7 the head, it means the forceps are
positioned inaccurately and there is a risk of their slipping during traction.
23.
24. Step 4 of the procedure. After a tentative traction one begins extraction of the head.
• The right index and third fi nger are placed on Busch’s hooks, middle finger between the
separating forceps branches while the thumb and little finger clasp the handles on the sides.
• The left hand grips the handle from below.
• When extracting the head one should consider the nature, force and direction of tractions.
Step 5 of the procedure. The sequence of removing the forceps for the head to crown is as
follows:
• take the right handle by the right hand, the left handle by the left hand and unlock the
forceps by drawing the hands apart;
• Retrieve the blades in the inverse order of how they were inserted: first retrieve the right
handle and then the left one;
• when removing the blades the handles should deflect in the direction opposite the inguinal
fold.
27. COMPLICATIONS :
The following complications arise upon forceps delivery.
• Slipping of the forceps can be vertical (over the head in outside direction) or
horizontal (backward or forward). Forceps can slip due to incorrect grasping of the
head, incorrect locking, fetal head disproportion.
Slipping carries a risk for severe injury to the birth canal: ruptures in the perineum,
vagina,clitoris,rectum, and bladder.
• Birth canal injury :These include injury to the vagina and perineum,less often to the
cervix.
Rupture of the lower uterine segment and injury to pelvic organs present a severe
complication: the bladder and rectum are usually affected when prerequisites for the
procedure are not met or the technique is not executed appropriately.
28. • Fetal complications.
After the procedure the soft tissue on the fetal head usually shows edema with
cyanotic coloration.
If the head was compressed excessively, a hematoma may develop. A forcible pressure
of the blade on facial nerve can cause its paresis.
Severe complications are injury to fetal skull bones whose degree varies from
indention on the bone to fractures.
Cerebral hemorrhage constitutes a serious threat to fetal life.
• Postpartum infectious complications.
In itself, forceps delivery does not cause postpartum infection; however, the procedure
increases the risk of infection development so it requires adequate prevention during
the puerperium.
