The rate of operative vaginal delivery has remained fairly constant at around 10-13%.¹ However, there are emerging trends - for example, an increased tendency to conduct the delivery in the operating theatre, increased rate of Caesarean section at full dilatation, increasing failures of operative vaginal delivery (especially using the ventouse) and reduced attempts at instrumentation.²

Although it is now generally well established that there are significant risks associated with rotational and mid-cavity deliveries, there are low morbidity rates with most operative deliveries.^3,4 It should also be remembered that Caesarean section in the second stage of labour is not without considerable morbidity.^5,6

The operator should use their skill and judgement to determine the best choice of instrument for the situation.⁷ The Royal College of Obstetricians and Gynaecologists (RCOG) currently advises that the vacuum extractor should be the first choice.¹ Although this can have a higher failure rate and increased risks of cephalohaematoma, it has been shown to be associated with less maternal trauma.^8,9,10

Preventing assisted delivery

The following factors have been shown to be favourable in avoiding assisted delivery:

• Use of a partogram to monitor progress in labour.
• The mother labours in an upright or left lateral position.¹⁰
• Avoidance of use of epidural anaesthesia.

• Using oxytocin in a nulliparous mother with an epidural.
• Delaying active pushing in a nulliparous mother.¹²

Classification of forceps deliveries

Indications for instrumental delivery

They are used to shorten the second stage of labour:

Fetal:

• Presumed, or diagnosed (by fetal blood sampling) compromise.
• To protect the head during breech vaginal delivery.¹³

• To avoid Valsalva manoeuvre, e.g. maternal cardiac disease - Class 3 or 4.
• Hypertensive crises.
• Cardiovascular disease, particularly uncorrected malformations.
• Myasthenia gravis.
• Spinal cord injury.

• Nulliparous women:
  • Lack of progress for 3 hours (active and passive stage combined), with regional anaesthesia.
  • Lack of progress for 2 hours if no regional anaesthesia.
• Multiparous women:
  • Lack of progress for 2 hours if regional anaesthesia in place.
  • Lack of progress for 1 hour if no regional anaesthesia in place.
  • Maternal fatigue/exhaustion.

Contra-indications

• Predisposition to fractures in the fetus.
• Bleeding tendency or active bleeding in the fetus.
• Face presentation and vacuum extractor.
• Gestation ≤34 weeks.¹ Use with caution 34-36 weeks gestation.

Requirements for instrumental delivery

Full discussion and consent should take place with mother/parents.

(Acronym = FORCEPS):

• Fully dilated cervix.
• Occipito-anterior position preferably - occipito-posterior position (OP) delivery is possible with Kielland's forceps and vacuum.
• Ruptured membranes.
• Cephalic presentation.
• Engaged presenting part, i.e. the greater diameter of the baby's head has passed the pelvic brim.
• Pain relief is adequate.
  • Vacuum extraction or low forceps - minimum of perineal nerve block.
  • Mid-forceps - epidural or pudendal nerve block, or general anaesthetic.
• Sphincter (bladder) empty.

Higher failure rates

These are associated with:

• Maternal body mass index ≥30.
• Estimated fetal weight ≥4 kg.
• OP position.
• Mid-cavity deliveries.

These factors should prompt trial of delivery, with preparations to proceed to Caesarean section immediately if unsuccessful.

• The procedure should be abandoned if no descent is seen with 3 pulls.
• An incident report should be completed.
• Using differing instruments sequentially is not recommended.¹⁴ However the operator should balance this decision against the risks of subsequent caesarean section.

After delivery care

Analgesia

Routine paracetamol and diclofenac should be prescribed, if there are no contra-indications.¹

Antibiotics

There is no evidence that these should be routinely prescribed.¹⁵

Thromboprophylaxis

Each woman should be individually assessed for risk, e.g. immobility.

Bladder care

The woman should have fluid volume chart for the first 24 hours, to asses for retention and function. Referral to physiotherapy may be appropriate.

Outcomes

• Vacuum-assisted delivery has a lower rate of successful delivery, but is less likely to lead to Caesarean section than the use of forceps.¹⁶
• Vacuum-assisted delivery is also associated with less use of anaesthesia and fewer severe maternal injuries.¹⁷
• However, use of forceps following failed vacuum extraction can lead to a high level of damage to the mother. Adverse symptoms such as urinary and faecal incontinence are common in mothers with both forms of assisted delivery.^9,10
• Cephalhaematomas and retinal haemorrhages are well recognised sequelae of vacuum extraction, but usually have no long-term adverse effects.^8,18

Audit

Suitable subjects may include:

• Rate of use
• Rate of failures
• Incidence of maternal tears
• Neonatal trauma
• Standard of documentation

Document references

1. Operative Vaginal Delivery, Royal College of Gynaecologists (February 2011)
2. Loudon JA, Groom KM, Hinkson L, et al; Changing trends in operative delivery performed at full dilatation over a 10-year J Obstet Gynaecol. 2010 May;30(4):370-5. [abstract]
3. Chiswick ML, James D; Kielland's forceps. Br Med J. 1979 Mar 17;1(6165):747-8.
4. Gei AF, Belfort MA; Forceps-assisted vaginal delivery. Obstet Gynecol Clin North Am. 1999 Jun;26(2):345-70. [abstract]
5. Murphy DJ, Liebling RE, Verity L, et al; Early maternal and neonatal morbidity associated with operative delivery in second stage of labour: a cohort study. Lancet. 2001 Oct 13;358(9289):1203-7. [abstract]
6. Villar J, Carroli G, Zavaleta N, et al; Maternal and neonatal individual risks and benefits associated with caesarean delivery: multicentre prospective study. BMJ. 2007 Nov 17;335(7628):1025. Epub 2007 Oct 30. [abstract]
7. Intrapartum care, NICE Clinical Guideline (2007)
8. Johanson RB, Menon BK; Vacuum extraction versus forceps for assisted vaginal delivery. Cochrane Database Syst Rev. 2000;(2):CD000224. [abstract]
9. Johanson RB, Heycock E, Carter J, et al; Maternal and child health after assisted vaginal delivery: five-year follow up of a randomised controlled study comparing forceps and ventouse. Br J Obstet Gynaecol. 1999 Jun;106(6):544-9. [abstract]
10. Fitzpatrick M, Behan M, O'Connell PR, et al; Randomised clinical trial to assess anal sphincter function following forceps or vacuum assisted vaginal delivery. BJOG. 2003 Apr;110(4):424-9. [abstract]
11. Torvaldsen S, Roberts CL, Bell JC, Raynes-Greenow CH. Discontinuation of epidural analgesia late in labour for reducing the adverse delivery outcomes associated with epidural analgesia. Cochrane Database of Systematic Reviews 2007, Issue 4. Art. No.: CD004457. DOI: 10.1002/14651858.CD004457.pub2
12. Roberts CL, Torvaldsen S, Cameron CA, et al; Delayed versus early pushing in women with epidural analgesia: a systematic review and meta-analysis. BJOG. 2004 Dec;111(12):1333-40.
13. The management of breech presentation, Royal College of Obstetricians and Gynaecologists (2006)
14. Towner D, Castro MA, Eby-Wilkens E, et al; Effect of mode of delivery in nulliparous women on neonatal intracranial injury. N Engl J Med. 1999 Dec 2;341(23):1709-14. [abstract]
15. Liabsuetrakul T, Choobun T, Peeyananjarassri K, Islam M; Antibiotic prophylaxis for operative vaginal delivery. Cochrane Database of Systematic Reviews 2004, Issue 3. Art. No.: CD004455. DOI: 10.1002/14651858.CD004455.pub2.
16. Yeomans ER; Operative vaginal delivery. Obstet Gynecol. 2010 Mar;115(3):645-53. [abstract]
17. Boucoiran I, Valerio L, Bafghi A, et al; Spatula-assisted deliveries: a large cohort of 1065 cases. Eur J Obstet Gynecol Reprod Biol. 2010 Jul;151(1):46-51. [abstract]
18. Simonson C, Barlow P, Dehennin N, et al; Neonatal complications of vacuum-assisted delivery. Obstet Gynecol. 2007 Mar;109(3):626-33. [abstract]

Internet and further reading

• Alexander JM, Leveno KJ, Hauth JC, et al; Failed operative vaginal delivery. Obstet Gynecol. 2009 Nov;114(5):1017-22. [abstract]

Acknowledgements