Assisted Vaginal Delivery: A lost art? - neogs

Assisted Vaginal
Delivery:
A lost art?
Thomas F Baskett
Dept Obstetrics and Gynaecology
Dalhousie University
Halifax, Nova Scotia
1

USA. Nonfederal Hospitals: National Hospital
Discharge Survey
(Kozak, Weeks. Birth 2002;29:157)
%
1980
1990
2000
Forceps
17.7
8.6
4.0
Vacuum
0.7
6.1
8.4
Caesarean
16.5
23.5
22.9
Assisted Vaginal Delivery: Canada
1991 2001
Forceps 11.2% 6.8%
Vacuum 6.8% 10.6%
2

Second Stage of Labour
- Causes of Dystocia -
POWERS
PASSENGER
PASSAGES
Uterine*
Maternal*
Size
Malposition*
Malpresentation
Anomaly
Bony
Soft tissue*
Nullipara
Vs
Multipara
“The dynamics of labour
are more important
than the mechanics”
Ian Donald
3

Utero – Fetal – Pelvic relationships
Uterine work
Maternal effort
Fetal head - presentation
- position
- attitude (flexed/deflexed)
- synclitism (anterior/posterior)
- caput
- moulding
- station (cm)
Bony pelvis
Uterine work
Second stage of labour: Nullipara
No epidural Epidural
Oxytocin 10.1 pg/ml 0 pg/ml
increment
Uterine activity 1623 1368
(K pas/15 min)
Goodfellow BJOG 1983;90:214
Bates BJOG 1985;92: 1246
4

Second stage of labour
- Epidural –
RCT: 226 Nullipara ± Oxytocin
Oxytocin augmentation:
↓ Duration
↓ Pushing time
↓ Forceps delivery
Saunders et al BMJ 1989;229:1423
“Good contractions are worth
half an inch of true conjugate”
Ian Donald
Maternal effort
2 phases of second stage of labour:
• Passive →uterine work→descent to pelvic floor
• Active →maternal effort→ delivery
5

Maternal position
Recumbent
Upright
Duration
↓
= Assisted delivery =
= Epis / Tears =
Worse
Worse
Worse
Worse
Blood loss
Abnormal FHR
Apgar score
Cord pH
Maternal choice
↑
Fetal head
Position: transverse → anterior
→ posterior (larger diameter)
Attitude: flexed
deflexed (larger diameter)
Synclitism: anterior
posterior (disproportion)
Caput: subjective 1+ 2+ 3+
6

Bony pelvis
- Clinical pelvimetry-
Diagonal conjugate
Sacral bay
Side walls
Ischial spines
Sacro-spinous ligs
Subpubic arch
Inter-tuberous diam
≥ 12cm
Curved
Parallel
Not prominent
2 fingers (≥4cm)
Not narrow
≥ 10cm
9

Full Cervical Dilatation
Nature
1 hour
↓
Oxytocin augmentation
1 hour
↓
Maternal effort + Oxytocin
1 hour
↓
Decision re delivery
10

Indications for Assisted Vaginal
Delivery
Maternal:
Fetal:
Medical condition (↑ BP, cardiac)
Fatigue
Request
Non-reassuring FHR/fetal distress
Combination: Non-progressive labour
- Nullipara: 3 hr with regional, 2 hr without
- Multipara: 2 hr with regional, 1 hr without
Classification of Assisted Vaginal Delivery
Mid
O → + 1cm
OA, OT, ≤ 45° OP > 45°
Low
≥ 2cm but not on pelvic floor
OA, OT, ≤ 45° OP > 45°
Outlet On pelvic floor
Scalp visible without labial separation
OA, OP < 45°
ACOG Practice Bulliten No 17
Obstet Gynecol 2000;95. No 6.
11

Trial of Assisted Vaginal Delivery
‘It is a most comforting thought, when sitting
down to do a mid-forceps operation, that one
is not irrevocably committed to vaginal
delivery’.
Douglass & Kaltreider, 1953
‘Failure to deliver with forceps is not so great
a sin as failure to recognize defeat at an early
stage’.
Jeffcoate, 1953
Achieve vaginal delivery
Perineal trauma
Pelvic floor function (5yr)
Cephalhaematoma/Retinal
haemorrhage
Maternal worry
5 min Apgar
Forceps
+
+
=
=
Vacuum
=
+
+
=
Cochrane Database 2004
Soft Vs Rigid Vacuum Cup
9 trials. 1375 deliveries. Cochrane database, 2000
Less likely to achieve OR 1.65 (1.19 – 2.29)
vaginal delivery
Less scalp injury OR 0.45 ( 0.15 – 0.60)
12

‘The pneumatic tractor
….seems peculiarly
adapted to the purpose of
obstetric surgery, viz, as
a substitute for the steel
forceps, in the hands of
men who are deficient in
manual dexterity,
whether from
inexperience or natural
inaptitude’
13

Cup Application
Flexing Flexing Deflexing Deflexing
median paramedian median paramedian
Vacuum Delivery
- Traction -
• 1 Pull = traction during one uterine
contraction
• Descent (pelvic) phase – 3 pulls
• Outlet (perineal) phase – 3+ pulls
• ‘Pop-offs’ – undesirable
– careful reappraisal
16

Vacuum Delivery
- Traction –
• With uterine contraction and
maternal effort
• Finger-thumb position:
- finger assesses ‘negative traction’
- thumb → counter pressure
• Two-finger pull on traction bar
17

A prospective observational study of
1000 vacuum assisted deliveries with
the OmniCup device
T.F. Baskett, C.A. Fanning,
D.C. Young
Dept. Obstetrics and
Gynaecology
Dalhousie University
Halifax, Nova Scotia
Method of Delivery
Vacuum
Vacuum→forceps
Vacuum→spontaneous
Vacuum→forceps→C/S
Vacuum→C/S
No
871
98
11
10
10
(%)
(87.1)
(9.8)
(1.1)
(1.0)
(1.0)
Failure to deliver with Omnicup
2% Vacca 2001
4.8% (Vs soft 12.1%) Kar, UK.2005
8.2% Senanake, UK 2006
9.2% (Nullipara) Vacca 2006
12.7% Hayman, UK. 2002
30.1% (Vs 19.2% RCT) Groom, UK. 2006
34.4% (Vs 21.4% RCT) Attilakos, UK. 2006
12.9% Halifax, 2006
18

Failed Vacuum Assisted Delivery
Women’s Hospital, Halifax
Failed
Vacuum → Forceps 134
→ C/S 12
→ Spontaneous 11
→ Forceps → C/S 10
Total 167
No neonatal injury
“I consider it derogatory to any liberal man
to assume the office of a nurse, of an old
woman: it is an imposture to pretend that a
medical man is required at labour. Not only
is is beneath our dignity, but it is not within
our province. I do not consider the delivery
of a woman as a surgical operation”.
Sir Anthony Carlisle
Address to select committee on medical education.
British Parliament, 1834
Bibliography
Americian College of Obstetricians and Gynecologists.
Practice Bulletin No. 17. Operative Vaginal Delivery. Obstet
Gynecol 2000;95:6.
Attilakos,G Sibanda T, Winter C, Johnson N, Draycott T. A
randomised controlled trial of a new handheld vacuum
extraction device. Br J Obstet Gynaecol 2005;112: 1510-15
Baskett TF, Arulkumaran S (eds). Operative delivery and
intrapartum surgery. Clin Obstet Gynaecol. London:Bailliere
Tindal, 2002;16:pp131.
Baskett TF, Non-progressive labour: Dystocia. In: Essential
Management of Obstetric Emergencies. 4 th ed.,
Bristol: Clinical Press, 2004. 119-133.
19

Baskett TF, Calder AA, Arulkumaran S. Assisted vaginal
delivery. In: Munro Kerr’s Operative Obstetrics, 11 th
Centenary Edition. Edinburgh: Elsevier, 2007.pp 91-125.
Bates RG, Helm CW, Duncan A, Edwards DK. Uterine
activity in the second stage of labour and the effect of
epidural analgesia. Br J Obstet Gynaecol 1985;92: 1246-
50.
Bird GC, Importance of flexion in vacuum delivery. Br J
Obstet Gynaecol 1976;83: 194-200.
Goodfellow CF, Howell mg, Swaab DF. Oxytocin
deficiency at delivery with epidural analgesia. Br J Obstet
Gynaecol 1983;90 214-219.
Groom KM, Jones BM, Miller N, Patterson-Brown
S. A prospective randomised controlled trial of the
Kiwi OmniCup versus conventional cups for
vacuum-assisted vaginal deloivery. Br J Obstet
Gynaecol 2006;113: 183-9.
Hanson SL, Clarke SL, Foster JC. Active pushing
versus passive fetal descent in the second stage of
labor-a randomised controlled trial. Obstet Gynecol
2002;99:29-34.
Jong, PR, Johanson RB, Backson P et al.
Randomized trial of comparing the upright and
supine positions for the second stage of labour. Br J
Obstet Gynaecol 1997;104:567-71.
Royal College of Obstetricians and Gynaecologists.
Instrumental Vaginal Delivery. Guideline No. 26;
London: RCOG, 2005.
Saunders NJ, Spiby H, Gilbert L. Oxytocin infusion
during 2 nd stage of labour in primiparous women using
epidural analgesia: a randomized double-blind placebocontrolled
trial. BMJ 1989;299: 1423-26.
Society of Obstetricians and Gynaecologists of Canada.
Guidelines for Vaginal Birth. Clinical Practice Guidelines
No. 148. J Obstet Gynaecol Can 2004;26:747-53.
Vacca A. Handbook of Vacuum Delivery in Obstetric
Practice. 2 nd ed. Brisbane: Vacca Research, 2003.
20

USA/Canada Training Programmes
OUTLET:
LOW (45°):
MID:
Forceps
Vacuum
Forceps
Vacuum
Forceps
Vacuum
Forceps
Vacuum
Resident
100
100
92
92
80
82
38
47
Fellow
100
100
92
92
76
80
69
73
Hankins et al
Am J Perinatol
1999;16:23
21