Question 1 of 10

With regard to the classification of vacuum assisted deliveries (VAD):

1. when fetal scalp is visible at the introitus and the sagittal suture is rotated less than 45° from the vertical, VAD is classified as an outlet procedure

2. when station of the fetal head is +3cm and position is occipitotransverse, VAD is said to be a low rotational procedure

3. when station of the head is +2cm and fetal position is occipitoposterior, VAD is classified as a mid pelvic rotational procedure

4. when station is 0cm (at spines) and the fetal head is rotated more than 45°, VAD is classified as a high rotational procedure

5. when station of the head is +1cm and position is occipitoanterior rotated less than 45°, VAD is said to be a mid pelvic nonrotational procedure

Comment

The ACOG, the RANZCOG, the RCOG and the SOGC have agreed on the following classification for instrumental deliveries: (a) mid pelvis - the fetal cranium is at 0cm or +1cm station; (b) low pelvis - is at +2cm or +3cm station and (c) outlet pelvis - fetal scalp is visible at or outside the introitus and rotation does not exceed 45°.

In the Pre-Test you scored 3/5 on this question.

References

• American College of Obstetricians and Gynecologists Committee on Practice Bulletins. Operative Vaginal Delivery: ACOG Practice Bulletin No 17. June 2000.
• Royal College of Obstetricians and Gynaecologists Guidelines and Audit Committee. Operative Vaginal Delivery: Guideline No.26 October 2005.
• Society of Obstetricians and Gynaecologists of Canada Clinical Obstetric Practice Committee. Guidelines for Operative Vaginal Birth: Guideline No. 148, August 2004.
• Vacca A. Handout – Prerequisites and Technique for Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com.
• Vacca A. Essential Pre-reading for Masterclass in Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com.
• Vacca A. Handbook of Vacuum Delivery p35: Station and level of the fetal head
• Vacca A. Choices with Childbirth CD-ROM: see Station and level of the fetal head

Question 2 of 10

Provided the operator has been adequately trained, which of the following clinical situations may be regarded as contraindications for vacuum extraction:

1. lack of progress; occipitoposterior position; deflexed fetal head, station +1cm

2. occipitoanterior position; station of the fetal head +3cm; gestation 32 weeks

3. cervix 9cm dilated; left occipitoanterior position; station +2cm

4. second twin; station -1cm; fetal heart rate 90 beats per minute

5. occipitotransverse position; asynclitism; station +2cm; scalp blood sampling

Comment

Transverse arrest with asynclitism and OP position with deflexion of the fetal head can successfully be managed with the vacuum extractor provided the operator has been adequately trained and uses a posterior vacuum cup to achieve a flexing median cup application. Scalp blood sampling is not a contraindication for vacuum delivery whereas prematurity of less than 34 weeks, incomplete dilatation of the cervix and high station of the fetal head are generally regarded as contraindications.

In the Pre-Test you scored 3/5 on this question.

References

• American College of Obstetricians and Gynecologists Committee on Practice Bulletins. Operative Vaginal Delivery: ACOG Practice Bulletin No 17. June 2000.
• Royal College of Obstetricians and Gynaecologists Guidelines and Audit Committee. Operative Vaginal Delivery: Guideline No.26 October 2005.
• Vacca A. Handout – Prerequisites and Technique for Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com.
• Vacca A. Essential Pre-reading for Masterclass in Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com
• Vacca A. Handbook of Vacuum Delivery p32: Contraindications
• Vacca A. Choices with Childbirth CD-ROM: see Selection of patients for vacuum extraction

Question 3 of 10

Provided the operator has been adequately trained, which of the following clinical situations may be regarded as a ‘trial’ of vacuum extraction:

1. station +3cm; variable decelerations; slight moulding; OP position

2. station +1cm; reassuring fetal status; moderate moulding; OP position

3. station +2cm; reassuring fetal status; moderate moulding; OT position

4. station +2cm; nonreassuring fetal status; extensive moulding; OA position

5. station -1cm; reassuring fetal status; slight moulding; OA position

Comment

A high degree of moulding of the fetal head combined with nonreassuring fetal status increases the risk of vacuum delivery especially if the fetal head is already occipitoanterior and caution should be exercised if vacuum extraction is attempted. Similarly, a mid pelvic station together with occipitoposterior position, although not a contraindication for a well-trained operator, should probably be regarded as a trial of vacuum delivery. On the other hand, OP & OT fetal head positions at low stations (+2cm/+3cm) are not in themselves high risk procedures for operators who have been trained in rotational vacuum deliveries. Vacuum extraction is generally regarded as contraindicated if the head is not engaged (at high fetal station).

In the Pre-Test you scored 2/5 on this question.

References

• Royal College of Obstetricians and Gynaecologists Guidelines and Audit Committee. Operative Vaginal Delivery: Guideline No.26 October 2005.
• Vacca A. Handout – Prerequisites and Technique for Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com.
• Vacca A. Handbook of Vacuum Delivery p41: Trial of vacuum-assisted delivery
• Vacca A. Choices with Childbirth CD-ROM: see Selection of patients for vacuum delivery

Question 4 of 10

The principal benefit to be gained by promoting the use of soft cups over rigid cups is based on evidence from randomised trials showing that soft cups:

1. are more likely to succeed in delivering the infant

2. are less likely to injure the mother

3. are associated with fewer superficial scalp marks and abrasions

4. are associated with fewer cephalhaematomas

5. are less likely to cause subgaleal or intracranial haemorrhage

Comment

The evidence from randomised trials shows that the failure rate of soft cups is more than double that of rigid cups and that they are just as likely to be associated with maternal genital tract injury. Soft cups, however, are associated with fewer superficial scalp abrasions and cephalhaematomas than rigid cups, but there is no evidence to show that the more serious subgaleal or intracranial haemorrhages are less common with a soft cup vacuum extraction than with a rigid cup vacuum delivery.

In the Pre-Test you scored 2/5 on this question.

References

• O’Mahony F, Hofmeyr GJ, Menon V. Choice of instruments for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD005455. DOI: 10.1002/14651858.CD005455.pub2.
• Johanson R, Menon V. Soft versus rigid vacuum extractor cups for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2000, Issue 2. Art. No.: CD000446. DOI: 10.1002/14651858.CD000446.
• Vacca A. Handout – Prerequisites and Technique for Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com.
• Vacca A. Essential Pre-reading for Masterclass in Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com
• Vacca A. Handbook of Vacuum Delivery p26: Choice of vacuum cups; p83: Efficacy of VE; p95: Neonatal effects
• Vacca A. Choices with Childbirth CD-ROM: see Vacuum extractor cups in common use

Question 5 of 10

The following statements are derived from a meta-analysis of vacuum extraction versus forceps delivery:

1. the vacuum extractor is more effective than the forceps in deflexed OP positions of the fetal head

2. the vacuum extractor is more likely to fail than forceps to deliver the baby

3. more than 70% of failed vacuum extractions proceed to successful forceps delivery

4. the overall caesarean section rate is lower in the vacuum extraction group

5. use of the vacuum extractor is associated with a reduction of severe maternal injuries

Comment

There is no specific evidence to support the statement that the vacuum extractor is more effective than forceps for OP positions. Successful management of fetal malpositions with the vacuum extractor depends on the level of the operator’s training in the use of a posterior cup. The lower caesarean delivery rate in the vacuum group, despite a higher failure rate with the vacuum extractor, is sometimes quoted as an advantage of vacuum extraction but this paradox is only possible because the majority of failed vacuum deliveries are completed by forceps (85% in the latest Cochrane Systematic review). There is no doubt that correct use of the vacuum extractor is associated with fewer 3° and 4° perineal tears and vaginal lacerations than is found with forceps delivery. However, the use of forceps after unsuccessful vacuum delivery may be associated with a higher risk of injury to the fetus and to the mother’s genital tract.

In the Pre-Test you scored 3/5 on this question.

References

• O’Mahony F, Hofmeyr GJ, Menon V. Choice of instruments for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD005455. DOI: 10.1002/14651858.CD005455.pub2.
• Johanson R, Menon V. Vacuum extraction versus forceps for assisted vaginal delivery. Cochrane Database of Systematic Reviews 1999, Issue 2. Art. No.: CD000224. DOI: 10.1002/14651858.CD000224.
• Attilakos G, Sibander T, Winter C,Johnson N,Draycott T. A randomised controlled trial of a new handheld vacuum extraction device. BJOG 2005;112:1510-15.
• Groom KM, Jones BA, Mioller N, Paterson-Brown S. A prospective randomised controlled trial of the Kiwi OmniCup versus conventional ventouse cups for vacuum-assisted vaginal delivery. BJOG 2006;113:183-9
• Vacca A. Handout – Prerequisites and Technique for Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com
• Vacca A. Handbook of Vacuum Delivery p90: Vacuum extraction or forceps delivery?
• Vacca A. Choices with Childbirth CD-ROM: see Vacuum extraction and forceps delivery compared – in Efficacy of vacuum extraction

Question 6 of 10

Consider the following statements derived from randomised trials of the effects on the mother of vacuum extraction versus forceps delivery:

1. vacuum extraction can be performed using simpler forms of analgesia

2. vacuum extraction causes less discomfort during and following the procedure

3. vacuum extraction causes more worries about the baby for the mother

4. vacuum extraction is just as likely to injure the anal sphincter and pelvic floor muscles as forceps

5. vacuum extraction is less likely to be associated with long term sequelae such as urinary and faecal incontinence

Comment

The most complex of vacuum extractions can be undertaken by experienced operators using perineal infiltration or pudendal nerve block analgesia. The evidence suggests that vacuum extraction causes less discomfort during and after delivery but is associated with greater anxiety for the mother at the appearance of the cup marking and chignon on the scalp. Although vacuum extraction is less likely to cause anal sphincter and serious genital tract injury than forceps delivery there is no conclusive evidence at the present time that the vacuum extractor has advantages over the forceps for the prevention of long term bowel or urinary tract disturbances. For this reason, vacuum extraction should not be recommended as a preventive measure for these remote outcomes even though anal sphincter injury is listed as a high risk precursor for later faecal incontinence. In any case, there is now persuasive evidence of the short term benefits for the mother from vacuum delivery and that serious injury is frequently associated with incorrect technique and therefore may be avoidable. For this reason, training in the correct use of the vacuum device should be included in all training programs.

In the Pre-Test you scored 3/5 on this question.

References

• O’Mahony F, Hofmeyr GJ, Menon V. Choice of instruments for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD005455. DOI: 10.1002/14651858.CD005455.pub2.
• Johanson R, Menon V. Vacuum extraction versus forceps for assisted vaginal delivery. Cochrane Database of Systematic Reviews 1999, Issue 2. Art. No.: CD000224. DOI: 10.1002/14651858.CD000224.
• Vacca A. Handout – Prerequisites and Technique for Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com.
• Vacca A. Handbook of Vacuum Delivery p90: Vacuum extraction or forceps delivery?; p104: Effects of VE on the mother
• Vacca A. Choices with Childbirth CD-ROM: see Vacuum extraction and forceps delivery compared – in Efficacy of vacuum extraction

Question 7 of 10

Consider the following statements derived from a meta-analysis of the effects on the infant of vacuum extraction versus forceps delivery:

1. vacuum extraction is associated with more retinal haemorrhages

2. vacuum extraction is associated with more cephalhaematomas

3. more babies develop jaundice that requires phototherapy following vacuum delivery

4. intracranial haemorrhage is more common after vacuum than after forceps delivery

5. perinatal mortality between the two delivery methods is not significantly different

Comment

Although in the past more retinal haemorrhages were reportedly more common following vacuum extraction than after forceps delivery, the recent Cochrane systematic review shows no significant difference in incidence between the two delivery methods. In any case, the clinical significance is unclear as retinal haemorrhages appear to be transient lesions leaving no residual ill effects. Similarly, with regard to cephalhaematoma the systematic review shows a non-significant trend in favour of the forceps. Although the larger cephalhaematomas may take a few weeks to disappear completely, complications are rare and no specific therapy is required other than reassurance of the parents. Jaundice is not significantly more common following vacuum extraction than after forceps delivery nor is jaundice to a degree that requires phototherapy. Intracranial haemorrhage is not more common with vacuum extraction than forceps delivery and perinatal mortality and long term morbidity are the same for both methods of delivery.

In the Pre-Test you scored 1/5 on this question.

References

• O’Mahony F, Hofmeyr GJ, Menon V. Choice of instruments for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD005455. DOI: 10.1002/14651858.CD005455.pub2.
• Johanson R, Menon V. Vacuum extraction versus forceps for assisted vaginal delivery. Cochrane Database of Systematic Reviews 1999, Issue 2. Art. No.: CD000224. DOI: 10.1002/14651858.CD000224.
• Vacca A. Handout – Prerequisites and Technique for Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com.
• Vacca A. Handbook of Vacuum Delivery p95- p102: Effects of vacuum extraction on the infant
• Vacca A. Choices with Childbirth CD-ROM: see Neonatal jaundice – in Effects of vacuum extraction on the neonate

Question 8 of 10

Which of the following statements about cephalhaematoma and vacuum extraction are correct? Cephalhaematoma is:

1. more common after vacuum extraction than after forceps delivery

2. more common after vacuum extraction using rigid cups than soft cups

3. of clinical significance to the newborn infant

4. crosses over the cranial suture lines or fontanelles

5. usually apparent at one hour after birth

Comment

Data from the latest Cochrane Systematic Review comparing vacuum and forceps delivery reveal that cephalhaematomas are observed more frequently following vacuum extraction than forceps delivery but that the difference is not significant. On the other hand, the data show a significant difference in the incidence of cephalhaematomas in favour of soft cups compared with rigid cups. Cephalhaematomas occur in about 2% of babies born spontaneously and in about 6% of babies delivered by vacuum extraction. They are of little or no clinical significance to the infant but may cause anxiety to an unprepared parent. Because cephalhaematomas occur under the periosteum of the cranium they are confined to the limits of a cranial bone, usually the parietal, and do not cross suture lines. Therefore it is very unlikely that the baby will be haemodynamically compromised by the limited collection of blood that accumulates there. The so-called 'large cephalhaematomas' that are sometimes described in the literature are probably subgaleal haemorrhages. Cephalhaematomas are usually discovered some hours or days after the birth, may take a few weeks to resolve completely and only rarely develop complications.

In the Pre-Test you scored 1/5 on this question.

References

• O’Mahony F, Hofmeyr GJ, Menon V. Choice of instruments for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD005455. DOI: 10.1002/14651858.CD005455.pub2.
• Johanson R, Menon V. Soft versus rigid vacuum extractor cups for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2000, Issue 2. Art. No.: CD000446. DOI: 10.1002/14651858.CD000446.
• Vacca A. Handout – Prerequisites and Technique for Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com.
• Vacca A. Essential Pre-reading for Masterclass in Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com
• Vacca A. Handbook of Vacuum Delivery p98: Cephalhaematoma and subcutaneous haematoma
• Vacca A. Choices with Childbirth CD-ROM: see Cephalhaematoma and Subcutaneous haematoma – in Effects of vacuum extraction

Question 9 of 10

Which of the following statements about subgaleal haemorrhage and vacuum extraction are correct? Subgaleal haemorrhage is:

1. almost twice as common after vacuum extraction as after forceps delivery

2. just as common after vacuum extraction with soft cups as rigid cups

3. rarely associated with deflexing applications of the vacuum cup on the fetal scalp

4. usually apparent at one hour after birth

5. has major long term adverse sequelae for the neonate

Comment

Subgaleal haemorrhage (SGH) is much more than twice as common following vacuum extraction than forceps delivery. In fact, SGH after a forceps delivery of a term infant is quite rare unless the forceps delivery was preceded by attempted vacuum extraction. The incidence of SGH has not decreased with the introduction of soft cups into clinical practice. SGH are commonly associated with incorrect vacuum technique particularly deflexing and paramedian cup applications and are preventable by avoiding difficult vacuum deliveries. The scalp of babies who develop subgaleal haematomas (SGH) is separated from the underlying periosteum as a result of traction force during the vacuum extraction. Thus a space is created between the scalp and periosteum at the time of the vacuum procedure into which the sero-sanguineous fluid of the natural caput and the chignon may flow and slowly accumulate. In these babies, if the scalp over the chignon is palpated a short time after birth this small collection of fluid is usually detectable under the cup application site. Regular examinations should then be made following the vacuum extraction to ensure that bleeding does not continue into the space to become a subgaleal haematoma. Early diagnosis and prompt and effective treatment should reduce the infant morbidity and, provided the SGH was the only injury sustained, there should be no long term adverse consequences for the infant.

In the Pre-Test you scored 2/5 on this question.

References

• O’Mahony F, Hofmeyr GJ, Menon V. Choice of instruments for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD005455. DOI: 10.1002/14651858.CD005455.pub2.
• Johanson R, Menon V. Soft versus rigid vacuum extractor cups for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2000, Issue 2. Art. No.: CD000446. DOI: 10.1002/14651858.CD000446.
• Vacca A. Handout – Prerequisites and Technique for Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com.
• Vacca A. Essential Pre-reading for Masterclass in Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com
• Vacca A. Handbook of Vacuum Delivery p99: Subgaleal (subaponeurotic) haemorrhage
• Vacca A. Choices with Childbirth CD-ROM: see Subgaleal (subaponeurotic) haemorrhage – in Effects of vacuum extraction

Question 10 of 10

Which of the following recommendations for the prevention of subgaleal haemorrhage are likely to be effective:

1. increasing maternal voluntary effort and augmenting uterine contractions with oxytocin

2. achieving flexing and median applications of the vacuum cup

3. limiting the number of pulls and the duration of the procedure

4. abandoning the extraction after three detachments of the cup from the fetal scalp

5. use of soft cups in preference to rigid cups

Comment

Subgaleal haemorrhage is associated with excessive traction force. Therefore, the greater the maternal expulsive effort and strength of uterine contractions, the less traction force will be required for assisted vacuum delivery. Clinically significant subgaleal bleeding is almost always preceded by difficult vacuum extraction featuring a characteristic pattern of events that includes deflexing and paramedian cup applications, prolonged extractions with excessive number and strength of pulls, and multiple cup detachments with re-applications of the vacuum cup. The attempt at vacuum delivery should be ceased after a second detachment especially if the fetal head has not descended to the perineum. The evidence shows that soft cups are not associated with a reduction of the incidence of subgaleal haemorrhage.

In the Pre-Test you scored 3/5 on this question.

References

• American College of Obstetricians and Gynecologists Committee on Practice Bulletins. Operative Vaginal Delivery: ACOG Practice Bulletin No 17. June 2000.
• Royal College of Obstetricians and Gynaecologists Guidelines and Audit Committee. Operative Vaginal Delivery: Guideline No.26 October 2005.
• O’Mahony F, Hofmeyr GJ, Menon V. Choice of instruments for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2010, Issue 11. Art. No.: CD005455. DOI: 10.1002/14651858.CD005455.pub2.
• Johanson R, Menon V. Soft versus rigid vacuum extractor cups for assisted vaginal delivery. Cochrane Database of Systematic Reviews 2000, Issue 2. Art. No.: CD000446. DOI: 10.1002/14651858.CD000446.
• Vacca A. Handout – Prerequisites and Technique for Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com
• Vacca A. Essential Pre-reading for Masterclass in Vacuum-assisted Delivery. November 2010. In: Clinician’s Resources – Available online at www.vaccaresearch.com
• Vacca A. Handbook of Vacuum Delivery p99: Subgaleal (subaponeurotic) haemorrhage
• Vacca A. Choices with Childbirth CD-ROM: see Subgaleal (subaponeurotic) haemorrhage – in Effects of vacuum extraction