Operative Vaginal Delivery: Prerequisites, Forceps & Ventouse

Operative vaginal delivery in one place: when to do it, what must be true before you start, the step-by-step for forceps and ventouse, and when to stop. Based on the OLSS (Obstetric Life Saving Skills) lecture on operative vaginal deliveries at Hospital Sultan Haji Ahmad Shah (HOSHAS), Temerloh.

Definitions

Operative vaginal delivery: using a ventouse or forceps to assist and achieve a vaginal delivery.
Trial of operative vaginal delivery: an attempt at vaginal delivery with a threshold to abandon it if difficulties are met.

Indications and contraindications

Indications	Contraindications
Maternal: to shorten the second stage, an exhausted mother, prolonged second stage	Cervix not fully dilated
Fetal: abnormal CTG in the second stage	Signs of CPD: significant caput or moulding, high station, narrow pelvic outlet
	No descent with maternal contractions
	Face presentation
	Fetal causes
	Previous OASIS
	Indeterminate fetal position

Risk of failure: estimated fetal weight >4 kg, maternal obesity, OP position, an uncooperative mother, nulliparity, and maternal height.

Remark: CTG = cardiotocography; CPD = cephalopelvic disproportion; OASIS = obstetric anal sphincter injury; OP = occipito-posterior.

Before you attempt it

Know the lie, the presentation, the position (e.g. OA, OP), the station, whether there is asynclitism, a clinical pelvimetry, and the anaesthesia available.

Prerequisites: FORCEPS

	Prerequisite
F	Fully dilated os
O	Occiput position known: OA, OP or occiput transverse
R	Ruptured membranes
C	Contractions adequate; consent (verbal)
E	Empty bladder; experienced staff; episiotomy
P	Pelvis of adequate size
S	Station below the ischial spines, less than 1/5 palpable per abdomen

Remark: OA = occipito-anterior.

Forceps

Classification by station

Type	Criteria
Outlet	Fetal head at the perineum; sagittal suture in direct OA or direct OP
Low	Leading point of the skull at station +2 cm or more but not at the perineum; any degree of rotation
Mid	Station above +2 cm but not above the ischial spines; any degree of rotation; head at least 1/5 palpable per abdomen
High	Head 2/5 or more palpable and presenting part above the ischial spines. Not recommended

Forceps technique: A to J

	Step
A	Anaesthesia: adequate epidural or pudendal block; appropriate positioning and access
B	Bladder: catheterise
C	Cervix: fully dilated, membranes ruptured
D	Determine the position (direct OA or OP), station and pelvic adequacy
E	Equipment: complete, working forceps; anaesthesia support
F	Forceps: hold the left blade in the left hand like a pencil, with the right hand protecting the left vaginal wall. Introduce it between contractions, sliding and swinging it gently up along the pelvic curve. Repeat with the right blade in the right hand, then lock the blades
G	Gentle traction: downward traction with each contraction and maternal effort. Guard the perineum
H	Handle elevated: downward traction first, then upward following the pelvic curve. Don't elevate the handle too early
I	Incision: consider an episiotomy if a tear is imminent
J	Jaw: remove the forceps when the jaw is reachable or delivery is assured

Check the application before pulling:

The posterior fontanelle is 1 cm above the plane of the shanks.
The sagittal suture lies in the midline, perpendicular to the plane of the shanks.
You can't fit more than a fingertip between the fenestration of each blade and the fetal head.

Vacuum (ventouse)

No rocking or torque: only steady traction in the line of the birth canal.
Don't use a ventouse below 34 weeks' gestation or for a face presentation.
Tell her about the risk of intracranial haemorrhage.

Vacuum technique: A to J

	Step
A	Anaesthesia: adequate analgesia; appropriate positioning and access
B	Bladder: catheterise
C	Cervix: fully dilated, membranes ruptured
D	Determine the position, station and pelvic adequacy
E	Equipment: inspect the cup, pump and tubing; check the pressure
F	Fontanelle: put the cup over the flexion point, 3 cm in front of the posterior fontanelle along the sagittal suture. Raise the negative pressure initially and between contractions; sweep a finger round the cup to clear maternal tissue
G	Gentle traction: thumb of the non-dominant hand on the cup, index and middle fingers on the scalp. Pull with the dominant hand during contractions, downwards first, following the pelvic curve as the head descends. Guard the perineum
H	Halt (see below)
I	Incision: consider an episiotomy if a tear is imminent
J	Jaw: remove the cup when the jaw is reachable or delivery is assured

When to stop

No progress with three traction-aided contractions.
The cup pops off three times (Kiwi cup).
Time: the lecture gives two limits, more than 20 minutes elapsed on one slide and 30 minutes of pulling without significant progress on another. Follow your unit's protocol.

Complications

Maternal	Fetal
OASIS, extended vaginal tears, haematoma	Scalp laceration
Increased VTE risk	Cephalohaematoma, subarachnoid haemorrhage
Urinary and anal incontinence	Facial nerve palsy
Blood loss and anaemia	Retinal haemorrhage
Perineal pain	Hyperbilirubinaemia

Forceps or ventouse?

	Forceps	Ventouse
Benefits	No chignon needed; the pull is more likely to succeed; useful in maternal exhaustion; can deliver the after-coming head in a breech	Easier to learn; usable in OT position; less genital tract trauma
Risks	More OASIS and genital tract trauma	Higher failure rate; more fetal injury (cephalohaematoma, neonatal jaundice, retinal haemorrhage, intracranial injury); more likely to have a low 5-minute Apgar score

Remark: VTE = venous thromboembolism; OT = occipito-transverse.

Sources

Obstetric Life Saving Skills (OLSS) lecture: Operative Vaginal Deliveries. Hospital Sultan Haji Ahmad Shah (HOSHAS), Temerloh, 2026.