Pregnancy, Childbirth & Puerperium

Operative vaginal delivery: forceps and vacuum

Clinical Overview and When to Suspect Need for Operative Vaginal Delivery

— Prolonged second stage

– Nulliparous: ≥3 h with epidural, ≥2 h without

– Multiparous: ≥2 h with epidural, ≥1 h without

— Suspected fetal compromise — Category III tracing, recurrent late or prolonged decelerations, bradycardia

— Maternal indication to shorten second stage — cardiac disease (NYHA III/IV), severe hypertension, cerebrovascular malformation, exhaustion, neuromuscular disease

— Anesthesia adequate, Bladder empty, Cervix fully dilated, Determine position precisely, Equipment ready, Fontanelle identified, Gentle traction, Halt if no progress, Incision (episiotomy) considered, Just-in-case plan for cesarean

Operative vaginal delivery (OVD) = use of forceps or vacuum to assist expulsion of the fetus during the second stage of labor when spontaneous delivery is not imminent or is contraindicated

Accounts for ~3% of US deliveries; vacuum has overtaken forceps in frequency but both remain ACOG-endorsed when properly applied

Three classic indications (ACOG):

Prerequisites (mnemonic "ABCDEFGHIJ"):

Station requirement: fetal head must be engaged (at or below 0 station), with most authorities requiring +2 station or lower for safe OVD

Membranes must be ruptured; fetus must be vertex (or mentum anterior face for forceps only)

Step 3 management: Before attempting OVD, document indication, prerequisites, estimated fetal weight, and obtain verbal consent including discussion of cesarean as the alternative. A "trial of OVD" in the operating room is appropriate when success is uncertain and rapid conversion to cesarean may be needed.

Board pearl: Macrosomia (EFW >4500 g in non-diabetic, >4000 g in diabetic) and prior shoulder dystocia are relative contraindications to OVD because instrument-assisted delivery is itself a risk factor for shoulder dystocia.

Presentation Patterns and Key History

— Gestational age — OVD generally avoided <34 weeks (vacuum contraindicated <34 wk due to IVH risk)

— Parity and prior obstetric history — prior vaginal delivery predicts success; prior cesarean (TOLAC) is not an absolute contraindication but raises threshold

— Estimated fetal weight — clinical Leopold + bedside ultrasound; suspected macrosomia changes the calculus

— Diabetes status — gestational or pregestational diabetes increases shoulder dystocia risk

— Maternal medical conditions that contraindicate Valsalva — severe HTN, cardiac lesions, prior CVA, retinal detachment

— Coagulopathy or known fetal bleeding disorder — contraindicates vacuum (scalp trauma → cephalohematoma, subgaleal hemorrhage)

— Labor course — duration of second stage, adequacy of contractions, oxytocin use

— Analgesia — adequate regional or pudendal block essential, especially for forceps

— No descent over an hour of effective pushing

— Persistent occiput posterior or transverse with arrested rotation in a contracted midpelvis

— Suspected cephalopelvic disproportion

— Caput succedaneum or significant molding obscuring true station (false reassurance)

Typical Step 3 vignette: a laboring patient at term with epidural analgesia, fully dilated cervix, ruptured membranes, pushing for 2–3 hours without descent, or with sudden non-reassuring fetal heart tracing requiring expedited delivery

Key history elements to elicit/document:

Patterns suggesting failure is likely (and cesarean preferable):

Key distinction: Station refers to the bony presenting part, not the caput. A vignette describing "+3 station" with significant molding may actually represent a head still at 0 station — misjudging this is the classic setup for failed OVD and traumatic delivery.

Board pearl: Ask about HIV status and hepatitis C — both are relative contraindications to vacuum and to fetal scalp electrodes/sampling because of theoretical vertical transmission risk through scalp trauma.

Physical Exam Findings and Pre-Procedure Assessment

— Leopold maneuvers to confirm vertex, estimate fetal weight, assess descent (fifths palpable above pubic symphysis — 0/5 means fully engaged)

— Assess contraction frequency and strength; consider oxytocin if inadequate

— Cervix: must be fully dilated and retracted

— Membranes: must be ruptured

— Station: must be engaged, ideally +2 or lower (low or outlet); midpelvic OVD (0 to +2) is permitted but higher risk

— Position: identified by palpating sagittal suture and fontanelles

– Anterior fontanelle: diamond-shaped, 4 sutures

– Posterior fontanelle: triangular (Y-shaped), 3 sutures

— Asynclitism and molding noted

— Pelvic adequacy: diagonal conjugate, ischial spines, sacral curve, pubic arch >90°

— Outlet: scalp visible at introitus without separating labia, skull at pelvic floor, sagittal suture in AP or ROA/LOA/OP, rotation ≤45°

— Low: leading point of skull ≥+2 station, two subtypes (rotation ≤45° vs >45°)

— Mid: head engaged but leading point above +2

— High: not engaged — never appropriate for OVD

— Continuous EFM with category I or recoverable II tracing during placement

— Category III tracing → expedite delivery by whichever route is fastest

Maternal abdominal exam:

Pelvic exam — the critical step:

ACOG classification of OVD by station and rotation:

Fetal assessment:

Step 3 management: If position cannot be confidently determined by digital exam, perform intrapartum transabdominal or transperineal ultrasound before instrument placement — misidentification of fetal head position is a leading cause of failed vacuum and neonatal injury.

Board pearl: Empty the maternal bladder with an in-and-out catheter immediately before OVD — a full bladder displaces the uterus, impedes descent, and increases risk of bladder laceration.

Diagnostic Workup — Pre-Procedure Labs, Imaging, Monitoring

— CBC — anemia worsens tolerance of hemorrhage

— Type and screen (type and crossmatch if hemorrhage risk elevated)

— Platelet count — thrombocytopenia (<50K) is a relative contraindication

— Coagulation studies if preeclampsia, abruption, or known coagulopathy

— Continuous external EFM or fetal scalp electrode throughout

— Document category of tracing immediately before, during, and after OVD attempt

— Category I: baseline 110–160, moderate variability, no late/variable decels, accelerations present/absent

— Category II: indeterminate — most tracings prompting OVD fall here

— Category III: absent variability with recurrent late decels, recurrent variable decels, or bradycardia; OR sinusoidal pattern → deliver expeditiously

— Confirm fetal position when digital exam ambiguous

— Estimate fetal weight if macrosomia suspected

— Confirm vertex presentation (face, brow, breech are contraindications to vacuum; mentum anterior face permits forceps only by experienced operator)

— Indication

— Prerequisites met

— Position, station, EFW

— Type of instrument, number of attempts/pop-offs, duration

— Maternal and neonatal outcomes including any lacerations or fetal trauma

OVD is a clinical decision made in real time; "diagnostic workup" here means the pre-procedure data ensuring safety and the intrapartum monitoring confirming need

Maternal labs already available from admission:

Fetal monitoring:

Bedside ultrasound indications:

Imaging NOT routinely indicated: pelvimetry (X-ray or CT) has been shown to not predict success and exposes fetus to radiation

Documentation requirements (medicolegally critical):

CCS pearl: In a CCS-style case of prolonged second stage with category II tracing, order: bedside ultrasound for position, in-and-out catheter, IV access confirmed, anesthesia at bedside, NICU/pediatrics notified, and OR available for backup cesarean — then proceed with OVD.

Board pearl: Always document pH from cord gases after OVD for category II/III tracings — provides objective evidence of fetal status at delivery and is invaluable medicolegally.

Choosing the Instrument — Forceps vs Vacuum Decision-Making

— Simpson forceps: elongated cephalic curve, ideal for molded heads of nulliparous patients (outlet/low forceps)

— Elliot forceps: rounded cephalic curve, ideal for unmolded heads of multiparous patients

— Tucker-McLane: similar to Elliot, often used for rotation

— Kielland forceps: minimal pelvic curve, designed for rotation of OT or OP positions — high skill requirement, largely fallen out of US training

— Piper forceps: specifically for aftercoming head in breech delivery

— Soft cup (silastic) — less scalp trauma, higher failure rate

— Rigid cup (metal/plastic) — higher success, more scalp injury

— Kiwi OmniCup — handheld, disposable, most common in US

— Higher success rate (fewer failures)

— Usable <34 weeks

— Can be used for face presentation (mentum anterior)

— Better for rotational deliveries

— Less maternal perineal trauma (lower rate of 3rd/4th degree laceration)

— Less anesthesia required

— Less operator skill needed (more forgiving)

— Lower rate of facial nerve injury

— Gestational age <34 weeks (IVH risk)

— Fetal coagulopathy or bleeding disorder

— After fetal scalp blood sampling (relative)

— Face or breech presentation

— Suspected fetal-maternal blood-borne infection transmission concern

Both instruments are ACOG-endorsed; choice depends on operator experience, clinical scenario, and contraindications

Forceps types and uses:

Vacuum devices:

Forceps advantages:

Vacuum advantages:

Vacuum disadvantages/contraindications:

Key distinction: Forceps → more maternal trauma (lacerations, hematomas); Vacuum → more neonatal scalp trauma (cephalohematoma, subgaleal hemorrhage, retinal hemorrhage). This trade-off underlies most board questions on instrument choice.

Sequential use of both instruments is discouraged — combining vacuum and forceps roughly doubles the risk of significant neonatal injury (intracranial hemorrhage, brachial plexus injury) and should be avoided unless the head is on the perineum and delivery is imminent.

Risk Stratification — Predicting Success and Choosing OVD vs Cesarean

— Multiparity

— Lower station (+2 or lower)

— Occiput anterior position

— Adequate maternal effort/Valsalva

— Estimated fetal weight <4000 g

— Absence of significant caput/molding

— Adequate maternal pelvis on clinical pelvimetry

— Nulliparity with mid-station arrest

— Occiput posterior or transverse, especially with rotation needed

— Suspected macrosomia (EFW >4000 g with diabetes, >4500 g without)

— Maternal BMI >30

— Significant caput succedaneum (suggests true station higher than felt)

— Prolonged second stage with no descent despite adequate contractions

— When success is uncertain, perform the attempt in the operating room with anesthesia and surgical team ready for immediate cesarean

— Discontinue attempt if:

– No descent with traction over 3 contractions

– Vacuum pop-offs ≥3 times

– Total application time >20 minutes (vacuum) or no progress over 3 forceps pulls

– Delivery not accomplished within reasonable time frame

— Head not engaged (above 0 station)

— Position cannot be determined

— Suspected cephalopelvic disproportion

— Operator lacks training/experience for the indicated procedure

— Patient declines OVD after informed consent

Factors predicting successful OVD:

Factors predicting failure (consider primary cesarean instead):

The "trial of OVD" concept:

Cesarean preferred over OVD when:

Step 3 management: Avoid "heroic" OVD attempts. The 2020 ACOG Practice Bulletin emphasizes that abandoning a failed OVD attempt and proceeding to cesarean is appropriate practice, not failure. Continued attempts after lack of descent dramatically increase neonatal morbidity.

Board pearl: A failed vacuum followed by forceps (or vice versa) carries roughly the same risk of significant neonatal morbidity as a failed OVD followed by cesarean — but combined instrument use adds neonatal trauma without benefit. Pick one instrument, commit, and convert to cesarean if it fails.

Forceps Technique and Pharmacologic/Anesthetic Considerations

— Forceps generally require regional anesthesia (epidural top-up or spinal) — pudendal block alone is usually inadequate

— Vacuum can often be performed with pudendal block or even local infiltration

— Discuss epidural top-up with anesthesia team before procedure

— Confirm prerequisites (ABCDEFGHIJ)

— "Ghost" the application — hold both blades in front of perineum in the orientation they will assume

— Apply left blade first to maternal left side using left hand; insert posteriorly and rotate into position alongside fetal head

— Apply right blade to maternal right side

— Articulate the blades — they should lock easily; difficulty suggests malposition

— Check application:

– Posterior fontanelle 1 cm above plane of shanks

– Sagittal suture perpendicular to plane of shanks

– Lambdoid sutures equidistant from blades

– Fenestrations admit no more than a fingertip

— Traction with maternal effort, following pelvic curve (Pajot maneuver: downward + outward, then upward as head crowns)

— Remove blades in reverse order as head delivers

— Not routine; consider mediolateral if needed (lower rate of extension to 3rd/4th degree compared to midline)

— Midline episiotomy + forceps = highest risk of severe perineal laceration

Anesthesia requirements:

Forceps application steps:

Episiotomy:

Oxytocin: continue or initiate to ensure adequate contractions; OVD with inadequate uterine effort is more likely to fail

Prophylactic antibiotics: Recent RCTs (ANODE trial) support a single dose of amoxicillin-clavulanate (or cefazolin if pen-allergic) after OVD to reduce maternal infection — now ACOG-recommended

Step 3 management: After OVD, administer prophylactic IV antibiotic (amoxicillin-clavulanate 1.2 g or cefuroxime + metronidazole), inspect for perineal/vaginal/cervical lacerations under good lighting, and ensure third-stage management with active oxytocin to reduce postpartum hemorrhage risk (which is elevated after OVD).

Board pearl: "Phantom application" rule — if forceps blades don't articulate easily, the position is wrong. Force is never the answer. Remove blades, reassess position (consider ultrasound), and reapply or convert to cesarean.

Vacuum Technique and Procedural Pitfalls

— Confirm prerequisites

— Identify flexion point — on the sagittal suture, ~3 cm anterior to posterior fontanelle (~6 cm posterior to anterior fontanelle)

— Place cup center over flexion point — promotes flexion of head and minimum diameter through pelvis

— Sweep finger around entire cup edge to ensure no maternal tissue (cervix, vagina) is trapped

— Increase suction to ~600 mm Hg (or per device) during contractions

— Apply traction only during contractions and maternal pushing, in line with pelvic axis

— Release suction to baseline between contractions (some operators maintain steady pressure — both acceptable)

— Max 3 pop-offs (cup detachments)

— Max 3 sets of pulls without descent → abandon

— Max total application time ~20 minutes (some say 30); after this, scalp trauma escalates

— Often due to misplacement off flexion point → reapply once

— May indicate inadequate suction, maternal tissue trapped, or true CPD

— Recurrent pop-offs = strong signal to abandon and proceed to cesarean

— Initially downward (toward floor) to follow pelvic axis

— Curve upward as head crowns (Ritgen-like maneuver)

— Avoid rocking, twisting, or rotational forces with vacuum — rotation should be allowed to occur passively

— Cephalohematoma (subperiosteal, limited by suture lines) — 14–16%

— Subgaleal hemorrhage — potentially fatal; can hold entire neonatal blood volume; presents as boggy, fluctuant scalp crossing suture lines

— Retinal hemorrhage (usually self-limited)

— Scalp lacerations and bruising (chignon)

— Intracranial hemorrhage (rare)

— Neonatal jaundice from hematoma resorption

Vacuum extractor application:

Rules of thumb (ACOG "3-3-3"):

Pop-off troubleshooting:

Traction direction:

Vacuum-specific complications to discuss in consent:

CCS pearl: After vacuum delivery, order serial neonatal head/scalp exams in the first 24–48 hours and monitor neonatal hematocrit, bilirubin, and vital signs to detect subgaleal hemorrhage early. Tachycardia and pallor in a vacuum-delivered neonate is subgaleal hemorrhage until proven otherwise.

Board pearl: The chignon (artificial caput from vacuum suction) is expected and resolves in hours to days — distinguish from cephalohematoma (resolves in weeks) and subgaleal hemorrhage (emergent).

Special Populations — Preterm, Macrosomia, and Multiple Gestation

— Vacuum is contraindicated <34 weeks due to fragile fetal cranium and elevated IVH risk

— Forceps may be used by experienced operators when indicated

— Vacuum between 34–36 weeks is relatively contraindicated; weigh carefully

— EFW >4500 g without diabetes, >4000 g with diabetes → OVD is relatively contraindicated

— Why: macrosomia + OVD greatly elevates shoulder dystocia risk and brachial plexus injury (Erb palsy)

— If OVD attempted in this setting, anticipate dystocia: extra hands at bedside, McRoberts and suprapubic pressure ready

— Lowered threshold for cesarean

— Even with EFW <4000 g, asymmetric fetal growth (large shoulders/torso relative to head) increases dystocia risk

— Vaginal delivery of twin A: OVD acceptable using standard criteria

— Vacuum on twin B — controversial; forceps generally preferred if needed

— Internal podalic version + breech extraction is often the alternative for non-vertex twin B

— OVD not contraindicated; success rates similar

— Watch for uterine rupture signs (fetal bradycardia, abdominal pain, loss of station)

— With undetectable viral load, vaginal delivery and OVD acceptable

— With detectable VL or unknown status, cesarean preferred; if OVD necessary, forceps preferred over vacuum to minimize scalp trauma and vertical transmission

— Aortic root concerns → shorten second stage with OVD to limit Valsalva

— OVD indicated to avoid maternal Valsalva-induced hemodynamic stress

— Often planned in advance; epidural pre-loaded; forceps usually chosen

Preterm fetus (<34 weeks):

Suspected macrosomia:

Diabetes (gestational or pregestational):

Twin gestation:

Prior cesarean / TOLAC:

Maternal HIV:

Maternal hepatitis C: Similar logic — avoid vacuum if possible

Connective tissue disease (Marfan, Ehlers-Danlos):

Severe cardiac disease or pulmonary hypertension:

Step 3 management: For a patient with NYHA III mitral stenosis at full dilation with category I tracing, plan assisted second stage with outlet forceps under dense epidural — do not allow prolonged pushing. Communicate plan with anesthesia and cardiology early in labor.

Board pearl: OVD + macrosomia + diabetes = shoulder dystocia setup. This triad appears repeatedly on boards as the lead-in to a brachial plexus injury question.

Special Populations — Maternal Conditions Mandating Shortened Second Stage

— NYHA III–IV heart failure

— Severe mitral or aortic stenosis

— Pulmonary hypertension

— Eisenmenger syndrome

— Marfan with aortic root >40 mm

— Mechanism: Valsalva → ↑ intrathoracic pressure → ↓ venous return → hemodynamic instability

— Prior intracranial hemorrhage or unruptured AVM/aneurysm (risk of rebleed with Valsalva)

— Severe myasthenia gravis (maternal exhaustion)

— Spinal cord injury above T6 (autonomic dysreflexia risk — though this is managed differently)

— Persistent severe HTN despite therapy

— Concern for cerebrovascular event with prolonged pushing

— Use OVD to expedite delivery once fully dilated

— Severe restrictive lung disease

— Inability to sustain Valsalva

— Subjective but valid indication

— Prolonged labor, dehydration, inadequate analgesia

— Recent retinal surgery or detachment

— Proliferative diabetic retinopathy (Valsalva → vitreous hemorrhage)

— Continue cardiac monitoring 24–72 h postpartum (autotransfusion volume shift can precipitate pulmonary edema)

— Avoid methylergonovine (vasoconstriction) for PPH in HTN/cardiac patients

— Avoid carboprost (Hemabate) in asthma

— Oxytocin and misoprostol generally safe

— All OVD neonates should be examined by pediatrics/NICU shortly after delivery

— Document scalp/face exam, cranial nerve function (VII for forceps facial palsy), and brachial plexus exam

— Educate parents on warning signs (excess sleepiness, poor feeding, scalp swelling, jaundice)

Beyond fetal indications, several maternal conditions make OVD the preferred mode of delivery to limit Valsalva, exhaustion, or cardiovascular stress

Cardiac disease:

Neurologic conditions:

Severe preeclampsia / eclampsia:

Pulmonary disease:

Maternal exhaustion:

Ophthalmologic:

Postpartum considerations in these patients:

Pediatric considerations (neonatal):

CCS pearl: For a parturient with severe preeclampsia at full dilation, while assembling for OVD, continue magnesium infusion, control BP with IV labetalol or hydralazine, place foley if not already, ensure NICU presence, and proceed with low forceps or vacuum to limit pushing time. Do not delay delivery for non-urgent imaging.

Complications and Adverse Outcomes

— Perineal lacerations:

– 3rd degree (anal sphincter involvement) — ~3× higher with forceps vs vacuum

– 4th degree (through rectal mucosa) — risk of fistula, fecal incontinence

– Midline episiotomy compounds risk

— Vaginal/cervical lacerations — inspect routinely after OVD

— Vulvar/vaginal hematoma — pelvic pain out of proportion, tachycardia, falling Hgb

— Bladder/urethral injury — usually from full bladder during OVD

— Postpartum hemorrhage — 2× baseline risk; preempt with active third-stage management

— Postpartum urinary retention — common after OVD with regional anesthesia

— Pelvic floor disorders — long-term ↑ risk of urinary incontinence, fecal incontinence, prolapse (forceps > vacuum > spontaneous)

— Infection — endometritis, perineal wound infection (mitigated by prophylactic antibiotics)

— Coccyx injury — fracture or persistent coccydynia

— Forceps-specific:

– Facial nerve palsy (Bell-like, usually resolves spontaneously)

– Facial bruising and lacerations

– Skull fractures (rare)

– Corneal abrasions

— Vacuum-specific:

– Cephalohematoma (~15%)

– Subgaleal hemorrhage (~0.5–1%, but high mortality if missed)

– Retinal hemorrhage (common, usually benign)

– Scalp lacerations

– Hyperbilirubinemia (resorption of scalp blood)

— Either instrument:

– Intracranial hemorrhage (rare; ~1/860 OVD vs 1/1900 spontaneous)

– Brachial plexus injury (Erb palsy, Klumpke palsy) — usually from shoulder dystocia following OVD

– Clavicle fracture (shoulder dystocia)

– Hypoxic-ischemic encephalopathy (more reflective of underlying indication than OVD itself)

— Diffuse, fluctuant scalp swelling crossing suture lines (unlike cephalohematoma)

— Tachycardia, pallor, hypotonia, falling hematocrit

— Can sequester >50% of neonatal blood volume

— Requires NICU admission, volume resuscitation, possible transfusion

Maternal complications:

Neonatal complications:

Subgaleal hemorrhage red flags (Step 3 favorite):

Key distinction: Caput succedaneum = scalp edema, crosses sutures, resolves in 24–48 h. Cephalohematoma = subperiosteal blood, does NOT cross sutures, resolves in weeks, may cause jaundice. Subgaleal hemorrhage = blood in loose areolar tissue, crosses sutures, life-threatening.

Board pearl: Erb palsy after OVD = C5–C6 injury → "waiter's tip" posture (arm adducted, internally rotated, forearm pronated, wrist flexed). Most resolve spontaneously; refer to pediatric neurology if no improvement by 3–6 months.

When to Escalate — Abandoning OVD and Calling for Help

— Vacuum: ≥3 pop-offs, ≥3 sets of pulls without descent, total application time >20 minutes, scalp trauma evident

— Forceps: inability to articulate blades, no descent with 3 traction efforts, excessive force required, position incorrect on reassessment

— Worsening fetal status during attempt

— Maternal instability

— Anesthesia at bedside for epidural top-up or rapid spinal/general

— NICU/pediatrics present at delivery (especially mid-pelvic OVD, category II/III tracing, suspected macrosomia, preterm)

— OB scrub team with cesarean instruments available

— Second OB attending for difficult application or trainee supervision

— Blood bank notified if hemorrhage risk elevated

— Call for help; document time of head delivery

— HELPERR mnemonic:

– Help — call OB, anesthesia, NICU

– Evaluate for episiotomy (mediolateral)

– Legs (McRoberts maneuver — hyperflex maternal thighs)

– Pressure (suprapubic, not fundal)

– Enter (rotational maneuvers — Rubin, Woods corkscrew)

– Remove posterior arm

– Roll patient to all fours (Gaskin maneuver)

— Bimanual massage, oxytocin, methylergonovine (if no HTN), carboprost (if no asthma), misoprostol

— Tranexamic acid 1 g IV within 3 hours

— Balloon tamponade (Bakri), uterine artery embolization, B-Lynch suture, hysterectomy if refractory

— Apgar <7 at 5 min, suspected encephalopathy → NICU evaluation, consider therapeutic hypothermia if HIE criteria met

— Subgaleal hemorrhage suspicion → NICU, type and cross, volume resuscitation

OVD abandonment criteria (any of the following should trigger conversion to cesarean):

Do NOT switch instruments after failure of the first — proceed to cesarean

Personnel to mobilize before/during OVD:

Shoulder dystocia preparation (anticipate with OVD):

Postpartum hemorrhage escalation after OVD:

Neonatal escalation:

Step 3 management: Time-box every OVD attempt. Set explicit limits before starting ("we will reassess after 3 pulls or 1 pop-off"), and communicate them to the team. Open communication and a clear stop rule are core patient-safety practices in OVD.

CCS pearl: After abandoned OVD with conversion to cesarean, clearly document the OVD attempt and reason for abandonment in the operative note — this is essential for medicolegal protection and continuity of care.

Key Differentials — Other Indications for Expedited Second Stage

— If contractions are inadequate (Montevideo units <200), oxytocin augmentation may resume progress without intervention

— Appropriate when: reassuring fetal status, maternal stability, no clear arrest

— Hands-and-knees position for OP malposition

— Squatting or side-lying to facilitate rotation and descent

— Often underutilized before jumping to OVD

— For persistent OP or OT position

— Operator inserts hand, flexes head, and rotates to OA

— Successful in 50–90% with experienced operator

— Often combined with subsequent OVD or allows spontaneous delivery

— Preferred when prerequisites for OVD not met (unengaged head, undetermined position, CPD)

— Preferred when operator lacks training in indicated OVD

— Preferred when patient declines OVD

— Rarely the answer; episiotomy without OVD only marginally shortens second stage

— Mediolateral preferred if used

— Covered in chunk 5; clinical scenario dictates choice

— Not used in modern US obstetrics

— Historical option in low-resource settings for shoulder dystocia or obstructed labor

— OVD acceptable in TOLAC; uterine rupture remains primary concern

— Sudden loss of station may indicate rupture, not labor arrest

When facing a prolonged or arrested second stage, OVD is one option — the differential of "what to do next" includes several alternatives that may be more appropriate

Continued expectant management with augmentation:

Position changes and ambulation:

Manual rotation:

Cesarean delivery:

Episiotomy alone:

Forceps vs vacuum (within OVD):

Symphysiotomy:

Trial of labor after cesarean (TOLAC) considerations:

Key distinction: "Prolonged second stage" alone is not an automatic indication for OVD — first ask: Are contractions adequate? Is position favorable? Is the patient pushing effectively? Optimize before intervening.

Board pearl: For OP position causing arrested labor with reassuring tracing, manual rotation to OA followed by spontaneous or assisted delivery is often more successful and less morbid than direct OVD of an OP head — particularly with forceps in inexperienced hands.

Key Differentials — Distinguishing OVD Complications

— Caput succedaneum: soft, pitting edema; crosses suture lines; present at birth, resolves 24–48 h; benign

— Cephalohematoma: firm, fluctuant; bounded by suture lines (subperiosteal); appears hours after birth, grows over 24–48 h, resolves over weeks; may cause jaundice

— Subgaleal hemorrhage: boggy, fluctuant, crosses suture lines AND extends to neck/ears; rapidly expanding; life-threatening — can sequester entire blood volume

— Chignon: artificial caput from vacuum cup; cup-shaped; resolves in hours

— Forceps-related facial nerve palsy — affects entire ipsilateral face, including forehead (LMN); usually resolves in days–weeks

— Congenital absent depressor anguli oris — only lower lip affected; forehead spared; benign asymmetry

— Central facial nerve injury — spares forehead (UMN); suggests intracranial pathology

— Erb palsy (C5–C6): "waiter's tip"; intact grasp; usually from shoulder dystocia

— Klumpke palsy (C8–T1): "claw hand"; absent grasp; ± Horner syndrome (ipsilateral ptosis, miosis, anhidrosis from T1 sympathetic involvement); rarer

— Total plexus injury: flaccid arm, absent grasp

— Clavicle fracture: pseudoparalysis from pain; crepitus; pseudo-improvement with healing

— Humeral fracture: crepitus, swelling

— Perineal hematoma: unilateral perineal/vulvar pain, mass, tachycardia → exam, ± drainage

— Retroperitoneal hematoma: flank pain, hemodynamic instability, falling Hgb without visible bleeding → CT, IR

— Endometritis: fever, uterine tenderness, foul lochia, days postpartum

— Symphyseal separation: anterior pelvic pain with ambulation; consider in difficult OVD

Post-delivery, multiple clinical entities can present similarly; the Step 3 exam often tests differentiation between benign and emergent findings

Neonatal scalp swelling differential:

Neonatal facial asymmetry differential:

Neonatal arm weakness differential:

Maternal postpartum pain differential after OVD:

Key distinction: A neonate with scalp swelling crossing sutures + tachycardia + falling hematocrit = subgaleal hemorrhage = emergency. A neonate with scalp swelling not crossing sutures + jaundice on day 3 = cephalohematoma = monitor. Get this right on test day.

Board pearl: Klumpke palsy with Horner syndrome in a neonate after difficult OVD or shoulder dystocia = injury to lower trunk of brachial plexus (C8–T1) including T1 sympathetic fibers — classic vignette.

Postpartum Plan — Maternal and Neonatal Discharge Considerations

— Inspect perineum, vagina, cervix for lacerations under good lighting; repair in layers with absorbable suture

— Empty bladder; assess for retention (post-void residual)

— Active management of third stage (oxytocin 10 IU IM or IV infusion)

— Prophylactic antibiotic dose (amoxicillin-clavulanate or alternative) per ANODE trial data

— Pain control: scheduled NSAIDs (ibuprofen) + acetaminophen; reserve opioids for severe pain with strict tapering

— Ice packs to perineum first 24 h, then sitz baths

— Stool softeners (docusate) — critical for 3rd/4th degree repair

— Avoid:

– Constipation (worsens perineal pain, risks repair breakdown)

– Heavy lifting >baby's weight for 2 weeks

– Intercourse until 6-week visit or comfort

— Continue:

– Iron supplementation if anemic

– Prenatal vitamin during lactation

– Stool softener until perineum healed

— Contraception counseling before discharge — progestin-only methods (POPs, DMPA, implant, LARCs) safe in lactation; combined hormonal contraception generally deferred 4–6 weeks

— Rh-negative mother: ensure RhoGAM given within 72 h if neonate Rh+

— Document neuro exam (especially for forceps: facial nerve; for vacuum: scalp exam)

— Bilirubin screening before discharge (cephalohematoma → ↑ jaundice risk)

— Hearing screen, newborn screen, vitamin K, hepatitis B vaccine, eye prophylaxis as usual

— Educate parents on signs of subgaleal hemorrhage and intracranial injury (excessive sleepiness, poor feeding, irritability, scalp swelling, seizures)

Immediate postpartum (first 24 hours):

Maternal discharge planning (typically day 1–2 postpartum):

Neonatal discharge considerations:

Step 3 management: After 3rd/4th degree laceration repair, prescribe scheduled stool softeners (docusate 100 mg BID) for at least 2 weeks, scheduled NSAIDs and acetaminophen for pain, sitz baths, and avoidance of suppositories/enemas. Schedule postpartum visit at 1–2 weeks (instead of standard 6 weeks) for wound check.

Board pearl: Universal delayed cord clamping (30–60 seconds) is still recommended after OVD unless neonatal resuscitation is needed immediately.

Follow-Up, Monitoring, and Long-Term Counseling

— Early visit at 1–2 weeks for women with 3rd/4th degree lacerations, hematoma, or postpartum mood concerns

— Comprehensive visit at 4–6 weeks (ACOG recommends "4th trimester" approach with earlier and more frequent contacts)

— Pelvic floor assessment at 6-week visit

— Urinary incontinence (stress, urge, mixed)

— Fecal or flatal incontinence (especially after 3rd/4th degree tear)

— Pelvic organ prolapse symptoms (bulge, pressure)

— Dyspareunia

— Persistent perineal pain

— Pelvic floor physical therapy — first-line for stress urinary incontinence and pelvic floor dysfunction

— Urogynecology — for persistent or severe incontinence/prolapse

— Colorectal surgery — for persistent fecal incontinence after 4th degree repair

— Edinburgh Postnatal Depression Scale (EPDS) at postpartum visit (and ideally before)

— Birth trauma after difficult OVD is a known PTSD trigger — screen and refer

— Counsel on perinatal mood disorders, encourage support groups

— History of OVD does not mandate cesarean in subsequent pregnancy

— Most women with prior OVD have spontaneous vaginal delivery next time

— Discuss patient experience and preferences

— Severe perineal injury (4th degree, ongoing incontinence) may warrant discussion of elective cesarean — shared decision-making

— Perineal pain may impede positioning — encourage side-lying nursing

— All standard postpartum analgesics compatible with breastfeeding

— Address before discharge AND reinforce at follow-up

— LARCs (IUD, implant) ideal for immediate postpartum or 6-week visit placement

— Ovulation can resume by 3 weeks postpartum in non-lactating women

Postpartum visit schedule after OVD:

Pelvic floor symptoms to screen for:

Referral pathways:

Mental health screening:

Counseling for future pregnancies:

Lactation:

Contraception:

Step 3 management: At the 6-week postpartum visit after forceps delivery with 3rd degree laceration, perform a focused pelvic exam to assess healing, ask specifically about urinary and fecal continence, pain with intercourse, and screen for postpartum depression with EPDS. Refer to pelvic floor PT proactively rather than waiting for severe symptoms.

Board pearl: Postpartum anal incontinence after 4th degree laceration affects up to 30% of women long-term — early PT referral and clear documentation of injury and counseling are standard of care.

Ethical, Legal, and Patient Safety Considerations

— Should ideally be obtained during labor before the urgent moment when possible — for women with prolonged labor or non-reassuring tracing trends, discuss OVD as a possibility well before it is needed

— Elements: indication, instrument choice, alternatives (continued labor, cesarean), risks (maternal: lacerations, hemorrhage, infection; neonatal: scalp trauma, fracture, nerve injury, rare ICH), and possibility of failure requiring cesarean

— Verbal consent is acceptable in urgent situations; document in the medical record

— Document discussion of alternative of cesarean delivery

— Indication for OVD

— Confirmation of prerequisites (cervix, membranes, station, position, anesthesia, bladder)

— Instrument used, application, number of pulls/pop-offs, duration

— Maternal and neonatal outcomes, lacerations, cord gases

— Personnel present (NICU, anesthesia)

— Reason for any abandonment and conversion to cesarean

— A patient may refuse OVD even when medically indicated; cesarean is the alternative

— A patient may request cesarean rather than OVD; this is permissible after informed consent

— Operator must have current training and privileges for the procedure attempted

— Trainees should perform OVD under direct supervision

— Rotational forceps (Kielland) require advanced training; many US programs no longer teach

— Handoffs during labor are a recognized error source — incoming providers may not appreciate the trajectory of failed pushing, atypical position, or prior maneuvers; require structured sign-out (SBAR) and reassessment before any OVD decision

— Severe neonatal injury (HIE, brachial plexus, ICH) may trigger institutional review and required disclosure to family

— Open disclosure of complications and errors is both ethically required and reduces malpractice claims (apology laws)

— Track institutional rates of OVD success/failure, 3rd/4th degree laceration, shoulder dystocia, neonatal injury

— Simulation training improves outcomes

Informed consent for OVD:

Documentation requirements (medicolegally essential):

Patient autonomy and refusal:

Operator credentialing and safety:

Transition of care risk:

Mandatory reporting and disclosure:

Quality and safety:

Step 3 management: After a difficult OVD with neonatal injury, engage in transparent disclosure with the family, document the discussion, ensure NICU and risk management are notified, and offer to coordinate follow-up specialty care. Defensive evasion harms both patients and clinicians; honesty plus support is the standard.

Board pearl: A pregnant patient with full decision-making capacity can refuse OVD or cesarean even if refusal endangers the fetus — court orders to override maternal refusal are extraordinarily rare and ethically discouraged.

High-Yield Associations and Rapid-Fire Clinical Facts

— Simpson — molded head (nullips)

— Elliot/Tucker-McLane — unmolded head (multips)

— Kielland — rotation

— Piper — aftercoming breech head

— Caput: crosses sutures, hours

— Cephalohematoma: respects sutures, weeks, jaundice risk

— Subgaleal: crosses sutures, life-threatening, shock

— Chignon: vacuum-induced, hours

— Methylergonovine if HTN

— Carboprost if asthma

ABCDEFGHIJ prerequisites for OVD: Anesthesia, Bladder empty, Cervix fully dilated, Determine position, Equipment ready, Fontanelle identified, Gentle traction, Halt if no progress, Incision considered, Just-in-case cesarean plan

3-3-3 rule for vacuum: max 3 pop-offs, max 3 pulls without descent, max ~20 min application

Forceps types:

Instrument trade-off: Forceps → ↑ maternal trauma; Vacuum → ↑ neonatal scalp trauma

Vacuum contraindicated <34 weeks (IVH risk)

Sequential instruments doubles neonatal injury — pick one, then convert to cesarean

Scalp lesion comparison:

Erb palsy (C5–C6): waiter's tip, intact grasp

Klumpke palsy (C8–T1): claw hand, ± Horner syndrome

Forceps facial palsy: entire face including forehead, usually resolves

Prophylactic antibiotic after OVD: single dose amoxicillin-clavulanate (ANODE trial) reduces maternal infection ~50%

Avoid in PPH after OVD:

Pelvic floor risk: forceps > vacuum > spontaneous for long-term incontinence

Macrosomia thresholds: EFW >4500 g (non-diabetic) or >4000 g (diabetic) = relative contraindication

OVD station requirement: engaged (≥0), ideally +2 or lower

Position confirmation: if unsure on digital exam → bedside ultrasound

Episiotomy: mediolateral preferred if needed; midline + forceps = highest 3rd/4th degree risk

HIV with undetectable VL: vaginal/OVD acceptable; otherwise forceps preferred over vacuum

Cardiac/neuro/retinal disease: OVD indicated to limit Valsalva

Active third-stage management after OVD is essential — PPH rate is doubled

Tranexamic acid 1 g IV within 3 h of PPH onset

Cord gases at every operative delivery for documentation

Universal pediatric/NICU presence ideal for mid-pelvic OVD, category II/III tracing, preterm, or macrosomia

Board pearl: When the stem mentions "scalp swelling crossing suture lines + tachycardia + pallor" in a vacuum-delivered neonate, the answer is subgaleal hemorrhage → NICU + volume resuscitation + transfusion.

Board Question Stem Patterns

— G1P0 at 41w, fully dilated, pushing 3 h with epidural, OA at +2, category I tracing, EFW 3400 g, fatigued → Answer: outlet/low forceps or vacuum (both acceptable; failure to act is wrong)

— G3P2 at 35 weeks with prolonged second stage and category II tracing → Answer: forceps (vacuum contraindicated <34 weeks; relative <36 weeks)

— HIV+ mother with detectable VL → forceps preferred to minimize scalp trauma

— Vacuum-delivered neonate, 6 h old, boggy scalp swelling crossing sutures, tachycardia, pallor, Hgb dropping → Answer: subgaleal hemorrhage; NICU + volume resuscitation + PRBC

— Day-3 neonate with firm scalp swelling bounded by sutures and jaundice → cephalohematoma with hyperbilirubinemia

— Macrosomic neonate of diabetic mother, vacuum delivery complicated by shoulder dystocia; arm adducted, internally rotated, forearm pronated → Erb palsy (C5–C6)

— Neonate with claw hand, absent grasp, ptosis and miosis of same eye → Klumpke (C8–T1) with sympathetic involvement

— Forceps-delivered neonate with unilateral facial asymmetry, including inability to wrinkle forehead → peripheral CN VII palsy from forceps; reassure, usually resolves

— Excessive bleeding with firm uterus → inspect for laceration (vaginal, cervical, perineal)

— Severe unilateral perineal pain + tachycardia + falling Hgb → vulvar/vaginal hematoma

— Vacuum with 3 pop-offs and no descent → proceed to cesarean; do NOT switch to forceps

— NYHA III mitral stenosis at full dilation → assisted second stage with forceps to limit Valsalva

— 3rd degree laceration during forceps delivery — what is the most important counseling? → stool softeners + early follow-up + screen for fecal incontinence + pelvic floor PT

— After OVD, single dose of amoxicillin-clavulanate to reduce infection (ANODE trial)

Stem type 1 — Choosing OVD vs cesarean:

Stem type 2 — Choosing forceps vs vacuum:

Stem type 3 — Subgaleal hemorrhage:

Stem type 4 — Cephalohematoma vs caput:

Stem type 5 — Erb palsy:

Stem type 6 — Klumpke + Horner:

Stem type 7 — Forceps facial palsy:

Stem type 8 — Postpartum bleeding after OVD:

Stem type 9 — When to abandon:

Stem type 10 — Indication for OVD:

Stem type 11 — Postpartum follow-up:

Stem type 12 — Prophylactic antibiotics:

Board pearl: When a stem describes a "pop-off" or "loss of suction" twice during vacuum and the question asks about the next step → the answer is almost always either reapply once more correctly OR proceed to cesarean — never "switch to forceps."

One-Line Recap

Operative vaginal delivery — forceps or vacuum applied to an engaged vertex with full cervical dilation, ruptured membranes, known position, adequate anesthesia, empty bladder, and a cesarean backup plan — is a high-impact, time-limited intervention whose safety depends entirely on meeting strict prerequisites, choosing the right instrument for the clinical context, abandoning the attempt at predefined limits rather than escalating force, and anticipating maternal hemorrhage/laceration and neonatal scalp/nerve injury with deliberate post-delivery surveillance.

Choose OVD for prolonged second stage, non-reassuring fetal status, or maternal indication to shorten Valsalva — only when ABCDEFGHIJ prerequisites are met and the head is engaged (ideally +2 or lower) with confirmed position

Choose the instrument based on context: forceps for preterm <34 weeks, rotational deliveries, HIV with detectable viral load, and dense maternal regional; vacuum for less maternal trauma and less anesthesia need — but never combine the two

Recognize complications: forceps → maternal lacerations and facial nerve palsy; vacuum → cephalohematoma, subgaleal hemorrhage (life-threatening, crosses sutures, shock), and retinal hemorrhage; either → brachial plexus injury from associated shoulder dystocia and elevated postpartum hemorrhage

Follow through: give prophylactic amoxicillin-clavulanate (ANODE), document cord gases and procedure details, monitor the neonate for scalp/neuro injury, support pelvic floor with early postpartum visit and PT referral after severe lacerations, screen for postpartum depression and birth trauma, and counsel that prior OVD does not mandate cesarean next time