Abstract
Objective
To describe temporal and regional variations in Canada in the use of operative vaginal
delivery (OVD) at term for singleton pregnancies by pelvic station between 2004 and 2013.
Methods
Rates of OVD among term singleton pregnancies in Canada (excluding Quebec) were estimated
using information from the Discharge Abstract Database of the Canadian Institute for
Health Information for the years 2004-2012 (n = 2 284 109). Deliveries were stratified
by pelvic station. Temporal trends were assessed using the Cochran-Armitage test for
linear trend in proportions by year. Geographic variation was assessed by calculating
the rate and 95% confidence interval of each mode of delivery from 2010-2012 for each
province and territory.
Results
Among singleton pregnancies at term, the OVD rate decreased from 12.0% in 2004 to
10.7% in 2012 (P < 0.001), whereas Caesarean section rates (excluding those following failed OVDs)
increased from 24.9% to 26.7%. Forceps deliveries decreased from 3.1% to 2.5%, primarily
due to decreases in midpelvic forceps delivery. Vacuum-assisted delivery increased
significantly at outlet and low stations (by 26.0% and 15.1%, respectively) and remained
stable at midpelvic station. The failed OVD rate was 0.3% and decreased by 23.7% (P < 0.001). There were large variations in OVD rates by province.
Conclusion
Temporal trends in OVD rates varied by pelvic station, with rates of outlet and low
OVD increasing and rates of midpelvic and failed OVD decreasing. Vacuum extraction
is increasingly replacing forceps deliveries at outlet and low stations, whereas Caesarean
sections are replacing forceps deliveries at midpelvic stations. Variations in OVD
rates across provinces suggest differences in instrument preference and/or an evolution
in standards of practice.
Résumé
Objectif
Décrire les variations temporelles et régionales caractérisant l’accouchement vaginal
opératoire (AVO) à terme en station pelvienne dans les cas de grossesse monofœtale
au Canada, de 2004 à 2013.
Méthodes
Nous avons estimé les taux d’AVO parmi les grossesses monofœtales menées à terme au
Canada (à l’exclusion du Québec), en utilisant les renseignements fournis par la base
de données sur les congés des patients de l’Institut canadien d’information sur la
santé pour la période de 2004 à 2012 (n = 2 284 109). Nous avons stratifié les accouchements
d’après la position pelvienne. Nous avons également évalué les tendances temporelles
à l’aide du test de Cochran-Armitage, afin de déterminer si les proportions variaient
linéairement selon l’année. Nous avons enfin déterminé la variation géographique en
calculant le taux et l’IC à 95 % de tous les modes d’accouchement réalisés dans chaque
province et territoire, de 2010 à 2012.
Résultats
Parmi les grossesses monofœtales menées à terme, le taux d’AVO a diminué pour passer
de 12,0 %, en 2004, à 10,7 % en 2012 (P < 0,001), tandis que le taux de césariennes a augmenté (sauf celles réalisées après
l’échec d’une tentative d’AVO), pour passer de 24,9 % à 26,7 %. La proportion d’accouchements
par forceps est passée de 3,1 % à 2,5 %. Ce recul est principalement attribuable à
une baisse du nombre d’accouchements par forceps en station mi-pelvienne. Le nombre
d’accouchements assistés par ventouse a augmenté significativement en position vulvaire
et par voie basse (de 26,0 % et de 15,1 %, respectivement) et est demeuré stable en
station mi-pelvienne. Le taux d’échecs de tentatives d’AVO, qui s’est établi à 0,3%,
a régressé de 23,7 % (P < 0,001). Les taux d’AVO varient largement selon la province.
Conclusion
Les tendances temporelles qui caractérisent les taux d’AVO varient selon la position
pelvienne. Ainsi, les taux d’AVO en position vulvaire et par voie basse ont augmenté,
alors que les taux d’AVO en station mi-pelvienne et d’échecs de tentatives d’AVO ont
diminué. De plus en plus, l’extraction par ventouse remplace les forceps dans les
cas d’accouchement assisté en position vulvaire ou par voie basse. Toutefois, la césarienne
est en voie de remplacer l’accouchement assisté par forceps en station mi-pelvienne.
La variation des taux d’AVO selon les provinces laisse supposer des différences quant
à la préférence pour les instruments et (ou) une évolution des normes de pratique.
Key Words
Abbreviations:
CCI (Canadian Classification of Interventions), CI (confidence interval), CIHR (Canadian Institutes of Health Research), ICD (International Classification of Diseases), NOS (not otherwise specified), OVD (operative vaginal delivery)To read this article in full you will need to make a payment
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References
- Births: final data for 2013.Natl Vital Stat Rep. 2015; 64: 1-65
- National variations in operative vaginal deliveries in Ireland.Int J Gynaecol Obstet. 2014; 125: 210-213
- Canadian Perinatal Health Report 2003.Health Canada, 2003 (Available at:) (Accessed on April 14, 2016)
Public Health Agency of Canada. Canadian Perinatal Health Report - 2008 Edition. Available at: http://www.phac-aspc.gc.ca/publicat/2008/cphr-rspc/index-eng.php. Accessed on April 14, 2016.
- Variation in the rates of operative delivery in the United States.Am J Obstet Gynecol. 2007; 196: 526.e1-526.e5
- Safe prevention of the primary cesarean delivery.Am J Obstet Gynecol. 2014; 210: 179-193
- Validation of the 1988 ACOG forceps classification system.Obstet Gynecol. 1991; 77: 356-360
- Operative vaginal delivery. Practice Bulletin No. 154.Obstet Gynecol. 2015; 126: e56-e65
- Effect of mode of delivery in nulliparous women on neonatal intracranial injury.N Engl J Med. 1999; 341: 1709-1714
- Validation of perinatal data in the Discharge Abstract Database of the Canadian Institute for Health Information.Chronic Dis Can. 2009; 29: 96-100
- Williams Obstetrics.ed 23. McGraw-Hill Medical, New York2010
- Changing trends in operative delivery performed at full dilatation over a 10-year period.J Obstet Gynaecol. 2010; 30: 370-375
- Operative vaginal delivery.Obstet Gynecol. 2010; 115: 645-653
- Operative vaginal delivery: current trends in obstetrics.Womens Health (Lond Engl). 2008; 4: 281-290
- Changes in maternal characteristics and obstetric practice and recent increases in primary cesarean delivery.Obstet Gynecol. 2003; 102: 791-800
- Trial of instrumental delivery in theatre versus immediate caesarean section for anticipated difficult assisted births.Cochrane Database Syst Rev. 2012; 10: CD005545
- Examination of data base in midforceps delivery study.Am J Obstet Gynecol. 1985; 153: 814
- The midforceps: maternal and neonatal outcomes.Am J Obstet Gynecol. 1985; 152: 176-183
- Midforceps deliveries: long-term outcome of infants.Am J Obstet Gynecol. 1986; 154: 764-768
- A comparison of the morbidity of midforceps and cesarean delivery.Am J Obstet Gynecol. 1990; 162: 1428-1434
- Comparison of maternal and neonatal morbidity in midforceps delivery and midpelvis vacuum extraction.Obstet Gynecol. 1986; 67: 594-597
- Neonatal and maternal outcome in low-pelvic and midpelvic operative deliveries.Am J Obstet Gynecol. 1990; 162: 1436-1444
- Guidelines for operative vaginal birth.J Obstet Gynaecol Can. 2004; 26: 747-761
- Comparison of “instrument-associated” and “spontaneous” obstetric depressed skull fractures in a cohort of 68 neonates.Am J Obstet Gynecol. 2005; 192: 165-170
- Early maternal and neonatal morbidity associated with operative delivery in second stage of labour: a cohort study.Lancet. 2001; 358: 1203-1207
- The effect of sequential use of vacuum and forceps for assisted vaginal delivery on neonatal and maternal outcomes.Am J Obstet Gynecol. 2001; 185: 896-902
- Maternal and neonatal outcome after failed ventouse delivery: comparison of forceps versus cesarean section.J Matern Fetal Neonatal Med. 2007; 20: 541-545
- Predictors of failed operative vaginal delivery: a single-center experience.Am J Obstet Gynecol. 2007; 197: 308.e1-308.e5
- Uses and limitations of routine hospital admission/separation records for perinatal surveillance.Chronic Dis Can. 1997; 18: 113-119
Article info
Publication history
Published online: May 18, 2016
Accepted:
March 1,
2016
Received:
January 1,
2016
Footnotes
Competing interests: None declared.
Identification
Copyright
Copyright © 2016 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.
