Coupon Accepted Successfully!


Operative Vaginal Delivery (Forceps and Vacuum)

ACOG Classification of Forceps and Vacuum Delivery According to Station and Rotation





1. Scalp is visible at introitus without separating the labia (station +3)

2. Fetal skull has reached pelvic floor

3. Sagittal suture is in anteroposterior diameter or right or left occiput anterior or posterior position

4. Fetal head is at or on the perineum

5. Rotation does not exceed 45°


Leading point of fetal skull is at station +2, and not on pelvic floor

Rotation is 45° or less (left or right occiput anterior to occiput anterior, or left or right OP to OP)

Rotation is greater than 45°

Mid pelvic

Station above +2 cm, but head is engaged


Not included in classification

In modem day obstetrics, forceps is not applied if station is above +2 (station should be at least +2 before applying forceps).

Prerequisites for Forceps Application

There are at least six prerequisites for successful application of forceps:

  1. The head must be engaged.
  2. The fetus must present as a vertex or by the face with the chin anterior. The position of the fetal head must be precisely known.
  3. The cervix must be completely dilated.
  4. The membranes must be ruptured.
  5. There should be no suspected cephalic-pelvic disproportion.

With the application of forceps, the head of the fetus is perfectly grasped only when the long axis of blades corresponds to occipitomental diameter.

Generally, the indications and prerequisites for the use of the vacuum extractor for delivery are the same as for forceps delivery.

Differences between forceps and vacuum



Traction force = +18 kg for primi, +13kg for multi Cervix should be fully dilated

Less fetal but more maternal complications

Preferred in fetal distress

Rotation forceps not applied nowadays


Can be applied on face presentation and after-coming head of breech


Can be applied on preterm fetus


Can be applied in cases of fetal coagulopathy and if recent scalp blood sampling has been done

Can be applied in cases of IUFD

Negative pressure = 0.8 kg/cm2 (600 mm Hg)


Minimum 7 cm dilation

More fetal but less maternal complications

Less preferred (as vacuum takes time-to build up)

Vacuum causes rotation and extraction

Cannot be applied on face presentation and after corn-

ing head of breech


Contraindicated on preterm fetus (increased risk of

intraventricular hemorrhage)

Contraindicated in cases of fetal coagulopathy and if

recent scalp blood sampling has been done

Should not be applied as chignon formation will not

occur in IUPD

When using rigid cups, it is recommended that the vacuum be created gradually by increasing the suction by 0.2 kg/cm2 every 2 min until a negative pressure of 0.8 kg/cm2 (600 mm Hg) is reached. With soft cups, negative pressure can be increased to 0.8 kg/ cm2 within 1 min.

Comparisons: Forceps Versus Vacuum

  1. There are significantly more third- and fourth-degree lacerations, in the forceps-delivered group.
  2. Conversely, the incidence of shoulder dystocia and cephalohematomas are more in the vacuum group.
  3. Investigators have found decreased maternal trauma by vacuum compared with forceps.
  4. Although retinal hemorrhage occasionally is seen with vacuum usage, it has no apparent long-term effects.

Johanson and Menon analyzed 10 randomized trials and confirmed that vacuum extraction was associated with less maternal but more fetal trauma, for example, cephalohematoma and retinal hemorrhage.





Prophylactic forceps

Forceps delivery only to shorten the second stage (e.g., heart disease patients)

Trial forceps

It is a tentative attempt of forceps delivery in case of suspected mild CPO with a pre-


amble declaration of abandoning it in favor of cesarean section if moderate traction


fails to overcome the resistance. It is to be performed in the operation theater

Failed forceps

When a deliberate attempt in vaginal delivery with forceps has resulted in significant


fetal or maternal trauma


Causes of Failed Forceps

  1. Failure of application
  2. Failure of locking
  3. Failure of extraction
  4. Undue maternal / fetal trauma

Test Your Skills Now!
Take a Quiz now
Reviewer Name