VACUUM VERSUS FORCEPS

Vacuum versus Forceps*ACOG Practice Bulletin #17 (June 2000)

**Johnson RB. The Cochrane Library Issue 4, 1999

• “Selection of the appropriate instrument and decisions about the maternal and fetal consequences should be based onclinical findings at the time of delivery.”

• A meta-analysis comparing vacuum extraction to forceps delivery showed that vacuum extraction was associated with significantly:

– Less maternal trauma

– Less need for general and regional anesthesia

Effect of Delivery on Neonatal InjuryTowner D et al. Effect of Mode of Delivery in Nulliparous Women on Neonatal

Intracranial Injury. NEJM 1999;341:1709

DELIVERY DEATH ICH OTHER

NSVD 1/5,000 1/1,900 1/216

C/S IN LABOR 1/1,250 1/952 1/71

C/S P VAC OR FORCEPS N/R 1/333 1/38

C/S W/O LABOR 1/1,250 1/2,040 1/105

VACUUM 1/3,333 1/860 1/122

FORCEPS 1/2,000 1/664 1/76

VACUUM & FORCEPS 1/1,666 1/280 1/58

BLESSINGS

This document should be cited as: Althabe F. Vacuum extraction versus forceps for assisted vaginal delivery: RHL commentary (last

revised: 14 November 2002). The WHOReproductive Health Library; Geneva: World

Health Organization.

Sources of support: Latin American Centre for Perinatology (CLAP). Pan American

Health Organization - W H O.

Acknowledgements: Agustín Conde Agudelo for useful suggestions.

VACUUM EXTRACTION VERSUS FORCEPS FOR ASSISTED VAGINAL DELIVERY

• USE OF THE VACUUM EXTRACTOR RATHER THAN FORCEPS FOR ASSISTED DELIVERY APPEARS TO REDUCE MATERNAL MORBIDITY.

• THE REDUCTION IN CEPHALHAEMATOMA AND RETINAL HAEMORRHAGES SEEN WITH FORCEPS MAY BE A COMPENSATORY BENEFIT.

VACUUM VERSUS FORCEPS

• Overview

• The decision to use a vacuum extractor instead of forceps in assisted vaginal delivery is based on the clinical situation and the experience and expertise of the doctor. For many physicians, these two instruments are interchangeable, while others feel more comfortable with one or the other. The use of the vacuum extractor has recently increased while the number of forceps deliveries has declined. Therefore, it is possible that a physician may have more experience using the vacuum extractor and this may be a key factor in the final decision. The advantages and disadvantages of these two methods are discussed next.

ADVANTAGES OF VACUUM DELIVERIES (VERSUS FORCEPS DELIVERIES)

LESS INJURY TO THE MOTHER'S SOFT TISSUES.

• Trauma to the vaginal walls /vaginal opening is decreased due to easy placement of the instrument on top of baby's head.

• The vacuum extractor does not increase the width of the presenting part of the fetus as can happen with forceps.

• The amount of vaginal trauma is directly related to the force of the traction. In most cases, the amount of traction that can be applied by vacuum is less than that produced by forceps.

• Therefore, the descent of the baby's head occurs in a more controlled fashion when the vacuum is used. When the head is delivered slowly, less tearing occurs.

• Significant maternal injuries were less likely when vacuum extraction was used. As the overall reduction in maternal injuries is the main benefit associated with vacuum extraction, a better description of these maternal outcomes would be desirable. The outcome "significant maternal injury" is not defined.

EASE OF PLACEMENT.

• Because of its design, the vacuum may be applied to the top of the baby's head as it becomes visible in the birth canal. Forceps, on the other hand, must encircle the baby's head and therefore it is extremely important to know the exact position of the baby's head.

• The newer, soft plastic cups are pliable and can be folded for insertion and maneuverability.

• There is also significant risk of injury to the vaginal walls during placement of the forceps. If the baby's head is tilted slightly to one side (asynclitic presentation), application of the forceps may be impossible.

• There are, however, contraindications to vacuum placement when the baby's head is in certain positions, so it is a requirement, nonetheless, to know the position of the baby's head.

LESS ANESTHESIA IS REQUIRED.

• Because the vacuum extractor is easier to apply and is associated with less trauma to the vagina, it requires less anesthesia.

• Although epidural anesthesia is preferable, vacuum extraction may be performed after injection of local anesthetic that numbs the lower vagina.

• When regional anesthesia (epidural or spinal block) is not possible because of time constraints or unavailability, vacuum extraction may be performed safely and comfortably after local injection of medication.

• The use of pudendal or general anaesthesia and pain during delivery were also less common in the vacuum group.

• The outcome "Regional and general anaesthesia" is presented in a subgroup analysis. Pudendal, epidural and general anaesthesia, are first analysed independently and a subtotal typical relative risk is calculated for each one.

FEWER BOWEL PROBLEMS.

• Less bowel incontinence compared to forceps delivery; most likely, this is due to potential for more vaginal trauma with forceps- more likely to result in vaginal tears that partially involve or even completely transect the anal sphincter and rectal lining.

• This type of injury is referred to as a fourth-degree laceration and can be associated with long-term anal sphincter dysfunction, resulting in occasional leakage of stool or gas.

LESS FORCE/ TRACTION IS APPLIED TO THE BABY'S HEAD.

• One study found that vacuum extraction exerted approximately 40% less force to the baby's head than forceps delivery.

• Although vacuum delivery may be associated with development of a bruise on top of the baby's head, the forceps may cause similar injuries and may result in more serious nerve or skull injuries.

DISADVANTAGES OF VACUUM DELIVERIES (VERSUS FORCEPS DELIVERIES)

THE VACUUM CUP MAY BECOME DISLODGED.

• When the second stage of labor has been prolonged, it is common to find that the baby's head has a significant amount of swelling at the presenting point., it may be difficult to obtain an optimal application of the cup against the baby's head and the cup may become detached.

• Improper placement of the vacuum cup may also result in detachment.

VACUUM EXTRACTION SHOULD BE USED ONLY IN FULL-TERM INFANTS.

• Because of an increased risk of bleeding in the brain in premature infants, the vacuum extractor should be used only in term infants.

• This limits the use of vacuum extraction to deliveries at 34 weeks of gestation or later. Forceps may be used safely to deliver preterm babies.

DELIVERY MAY TAKE LONGER.

• Vacuum traction should be applied only during contractions; therefore, vacuum-assisted vaginal delivery may be slower than forceps delivery.

• Forceps delivery may be performed with very little maternal effort, while vacuum-assisted delivery requires maternal participation.

SUCCESS RATES ARE SLIGHTLY LOWER FOR VACUUM DELIVERIES.

• Compared to vacuum extraction, the use of forceps resulted in greater success in achieving an instrument-aided vaginal delivery.

• However, the caesarean section rate was lower with vacuum extraction. This was so because after vacuum extraction failed, an attempt to deliver by forceps was more likely than the use of vacuum extraction after failure to deliver with forceps.

INTRACRANIAL HEMORRHAGE IS MORE COMMON.

• Due to the pressure of the suction cup applied to the baby's head, a particular type of serious bleeding, though rare, is more common with and unique to vacuum delivery

ASSOCIATED WITH A HIGHER INCIDENCE OF CEPHALHAEMATOMA AND RETINAL HAEMORRHAGE

• The use of vacuum was associated with a higher incidence of cephalhaematoma and retinal haemorrhage, although the latter was evaluated in a small proportion of infants.

TENDENCY TOWARDS A HIGHER INCIDENCE OF LOW APGAR SCORES AT FIVE MINUTES

• There was also a tendency towards a higher incidence of low Apgar scores at five minutes with the use of vacuum extraction. It is possible that the higher use of an alternative instrument after extraction failed in the vacuum group, contributed to the worse neonatal outcomes associated with the use of vacuum.

• No conclusion can be drawn about the effect on perinatalmortality ,no differences were observed.

BENEFITS OF FORCEPS (VERSUS VAGINAL DELIVERY)

• It is currently estimated that 10 to 15% of all babies born in are delivered via operative vaginal delivery, of which about two-thirds are forceps deliveries and the remainder are vacuum deliveries.

• The great majority of these forceps deliveries are outlet orlow-forceps deliveries. These deliveries pose little or no risk to mother or baby and are an advantage in some situations. For example, a baby who is shown to have an abnormal heart rate can be safely delivered by outlet or low forceps delivery and promptly evaluated with resuscitation as needed.

• Likewise, a woman who has been in the second stage of labor for several hours, who is unable to make further progress for whatever reason, and whose baby is at a station and position consistent with an outlet or low forceps delivery, will clearly benefit from such an operative vaginal delivery, with negligible risks to her baby.

• Finally, a woman who has a medical condition that prevents her from pushing in the second stage of labor can benefit from an assisted vaginal delivery. The most common examples of this include women with significant heart disease, respiratory compromise, or certain neurologic conditions.

• Forceps delivery places a woman at higher risk for blood transfusion and infection than does spontaneous vaginal delivery. However, compared to women who deliver by cesarean section following the onset of labor, women who deliver with forceps have significantly lower rates of these complications.

• An additional benefit of forceps delivery is the avoidance of a surgical scar in the uterus (compared to cesarean section). This is particularly significant if she plans to have additional pregnancies. Women with histories of cesarean section have increased risks in subsequent pregnancies (whether they opt to attempt labor first or plan for repeat cesarean) that may have been prevented by successful vaginal birth (with the use of forceps or not) in the previous pregnancy.

RISKS OF FORCEPS (VERSUS VAGINAL DELIVERY)

Potential risks associated with forceps deliveries must be balanced against the potential benefits. These risks may affect the mother or the baby.

The possibility of injury to the mother, in the form of vaginal tears or perineum incisions extending to rectum, increases –

o with rotations of greater than 45 degrees and

o at higher stations of the fetus's head. However, the likelihood of injury to the perineum is no greater for outlet forceps deliveries than for vaginal deliveries.

Rectal sphincter dysfunction occurs more frequently during forceps deliveries than spontaneous vaginal deliveries. This is due to muscle damage rather than nerve injury; the doctor can minimize this damage by pulling slowly and steadily with the forceps during contractions.

The mother's bladder should always be emptied (usually by catheterization) immediately prior to a planned forceps delivery. This will minimize risk of inadvertent bladder injury.

Forceps deliveries are also associated with a greater risk for blood transfusion than are spontaneous vaginal deliveries.

o Although elective (planned) cesarean births are associated with decreased chances of transfusion in comparison to forceps deliveries, emergency cesarean sections are associated with increased chances for transfusion in comparison to forceps deliveries.

Forceps deliveries are associated with an increased risk of injury to the newborn, particularly facial marks or injuries. On the other hand, forceps deliveries are associated with less bruising to the head (cephalohematoma) and retinal bleeding than are vacuum deliveries.

A prolonged second stage of labor should suggest an increased risk of shoulder dystocia.

o Although the frequency of shoulder dystocia is increased in forceps deliveries as compared to spontaneous deliveries, it does occur in spontaneous deliveries and its association with forceps deliveries has not been proven.

ALTERNATIVE TO CESAREAN SECTIONFORCEPS DELIVERY IN 21st CENTURY OBSTETRICS PRACTICE

• Obviously, there is a strong emphasis in this country on pregnancies ending with a healthy mother and baby. There is also clear evidence that the average age of women at their first childbirth is increasing and that the average number of births per woman is decreasing. All of these issues have contributed to the increased frequency of operative deliveries (primarily cesarean births) during the last quarter of twentieth century.

• There are now increasing numbers of health care providers, health care consumers, and health insurance companies who question the high cesarean birth rate and are searching for alternative and safe methods to reduce this rate.

• In selected cases, it is clear that forceps delivery can, and should, be used instead of cesarean section. When the criteria for forceps delivery are met and when there are appropriate, fetal and/or maternal indications for delivery, such assisted vaginal deliveries are appropriate and safe.

• In view of the fact that there is a reduction in the rate of maternal morbidity with vacuum extraction compared to the use of forceps, in settings with good experience of the use of vacuum extraction, this method should be promoted as the first choice when an instrument aided delivery has to be performed.

o In settings with little or no experience with the use of vacuum, training programmes in vacuum extraction at residency and senior level should be developed.

o The adoption of vacuum extraction as the first choice for instrument-aided delivery should be promoted only after a minimum standard of training has been reached.

o Participation of settings with low vaginal operative delivery rates should be encouraged.

• The trial should compare two policies of instrumental delivery: one in which vacuum extraction is the instrument of first choice and the other in which forceps is the first choice.

• The type of vacuum extraction method in this trial should be the one which is the best in terms of reducing failure rates and neonatal morbidity. The main outcomes to be studied should be neonatal outcomes and success in achieving vaginal delivery.

• Long-term follow-up of infants should also be considered as an important outcome to study.

• Such a follow-up study of the women and children participating in the Johanson et al trial (Keele 93 in the review) has been published .

• There were no significant differences between instruments in terms of bowel or urinary dysfunction although urinary incontinence was high overall (47%) at five years' follow-up. There were also no differences with regard to development and visual problems in children.

VACUUM VERSUS FORCEPS

Decision to Delivery Interval 14mts 8mts

Failed Delivery as 1stl line inst. 30% 20%

LSCS Dec (rot+seq) Inc.

Pain/Discomfort(A,D,24) Dec Inc

Analg./Anesthesia Less (pudendal) More

MAT. INJ-

1. Serious(Tocophobia) 20%(anus+inconti) 80%

2. Less Serious (Cx,vag.,epi.,perineum) Less More

3. Non Serious (PPH,stay,BT) Less More

Birth Asphyxia/APGAR -5 SAME

Skull fracture/s.cord inj. Less More

NERVE INJ.

1. 8 th hearing,6th vision(cranial distort) More Less

2. 7th facial-mandible ramus, cr.plxs Less More

Scalp- Stress-Cephalhematoma , More Less

o Scalp- Other inj.+Sub galeal Less More

ICH Less More

Face inj. Less More

Eye- Retinal Hem. More Less

Eye-S C Hem Less More

Jaundice N.Hyperbil. More Less

PNMR/Fetal Mortal. Less More

NICU SAME

F/U Adm. Less More