Incidence of obstetric anal sphincter injuries after training to protect the perineum: cohort study

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Objective

To compare the incidence of obstetric anal sphincter injuries (OASIS) in two time periods, before and after implementing a training programme for improved perineal support aimed at reducing the incidence of obstetric anal sphincter injuries. The secondary aim was to study incidence of obstetric anal sphincter injuries in subgroups defined by risk factors for OASIS.

Design

Population-based cohort study.

Setting

University hospital setting in Oslo, Norway.

Participants

Two cohorts of all delivering women in the largest hospital in Norway during two time periods (2003–2005 and 2008–2010) were studied. After excluding caesarean sections and preterm deliveries (< week 32), the study population consisted of 31 709 deliveries, among which 907 women were identified with obstetric anal sphincter injury.

Primary and secondary outcome measures

Incidence of OASIS in two time periods. Maternal, obstetrical and foetal risk factors for OASIS were collected from the hospital obstetric database. Univariate analyses and multivariate logistic regression analyses, presenting adjusted ODs for OASIS, were performed.

Results

The OASIS incidence was significantly reduced by 50%, from 4% (591/14787) in the first time period to 1.9% (316/16 922) in the second. This reduction could not be explained by changes in population characteristics or OASIS risk factors during the study years. The reduction of incidence of OASIS between the two study periods was consistent across subgroups of women; regardless of parity, delivery method and infant birth weight.

Conclusions

A marked reduction in the incidence of OASIS was observed in all studied subgroups of women after implementing the training programme for perineal protection. Further, this reduction could not be explained by the differences in patient characteristics across the study period. These findings indicate that the training programme with improved perineal protection markedly reduced the risk of OASIS.

Related collections

Most cited references 28

Record: found
Abstract: found
Article: not found

A multicenter interventional program to reduce the incidence of anal sphincter tears.

Elisabeth Hals, Pål Øian, Tiina Pirhonen … (2010)

In Norway, we have experienced a gradual increase in the incidence of obstetric anal sphincter injuries from under 1% in the late 1960s to 4.3% in 2004. This study was aimed to assess whether an interventional program causes a decrease in the frequency of anal sphincter tears. In all, 40,152 vaginal deliveries between 2003 and 2009 were enrolled in the interventional cohort study from four Norwegian obstetric departments. The focus of the intervention was on manual assistance during the final part of the second stage of labor. Data were analyzed in relation to occurrence of obstetric anal sphincter tears. The proportion of parturients with anal sphincter tears decreased from 4-5% to 1-2% during the study period in all four hospitals (P<.001). The tears associated with both noninstrumental and instrumental deliveries decreased dramatically. The number of patients with grades 3 and 4 anal sphincter ruptures decreased significantly, and the reduction was most pronounced in grade 4 tears (-63.5%) and least in 3c tears (-47.5%) (both P<.001). The number of episiotomies increased in two hospitals but remained unchanged in the other two. The lowest proportion of tears at the end of the intervention (1.2% and 1.3%, respectively) was found in the two hospitals with an unchanged episiotomy rate. The multicenter intervention caused a highly significant decrease in obstetric anal sphincter injuries. II.

0 comments Cited 53 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

A randomised controlled trial of care of the perineum during second stage of normal labour.

L Sames, U Bowler, M Renfrew … (1998)

To compare the effect of two methods of perineal management used during spontaneous vaginal delivery on the prevalence of perineal pain reported at 10 days after birth. Randomised controlled trial. Two English maternity care units. 5471 women who gave birth between December 1994 and December 1996. At the end of the second stage of labour women were allocated to either the 'hands on' method, in which the midwife's hands put pressure on the baby's head and support ('guard') the perineum; lateral flexion is then used to facilitate delivery of the shoulders, or the 'hands poised' method, in which the midwife keeps her hands poised, not touching the head or perineum, allowing spontaneous delivery of the shoulders. Perineal pain in the previous 24 hours reported by women in self-administered questionnaire 10 days after birth. Questionnaires were completed by 97% of women at 10 days after birth. 910 (34.1%) women in the 'hands poised' group reported pain in the previous 24 hours compared with 823 (31.1%) in the 'hands on' group (RR 1.10, 95% CI 1.01 to 1.18: absolute difference 3%, 0.5% to 5%, P = 0.02). The rate of episiotomy was significantly lower in the 'hands poised' group (RR 0.79, 99% CI 0.65 to 0.96, P = 0.008) but the rate of manual removal of placenta was significantly higher (RR 1.69, 99% CI 1.02 to 2.78; P = 0.008). There were no other statistically significant differences detected between the two methods. The reduction in pain observed in the 'hands on' group was statistically significant and the difference detected potentially affects a substantial number of women. These results provide evidence to enable individual women and health professionals to decide which perineal management is preferable.

0 comments Cited 48 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Trends in risk factors for obstetric anal sphincter injuries in Norway.

Svein Rasmussen, Per E Børdahl, Elham Baghestan … (2010)

To investigate risk factors for obstetric anal sphincter injuries in a large population-based data set, and to assess to what extent changes in these risk factors could account for trends in obstetric anal sphincter injuries. This is a population-based cohort study on data from the Medical Birth Registry of Norway between 1967 and 2004, including all vaginal singleton deliveries of vertex-presenting fetuses weighing 500 g or more. Women with their first birth before 1967 and births with previous obstetric anal sphincter injuries were excluded, leaving 1,673,442 births for study. The outcome variable was third- and fourth-degree obstetric anal sphincter injuries. The associations of obstetric anal sphincter injuries with possible risk factors were estimated by odds ratios (ORs) obtained by logistic regression. The occurrence of obstetric anal sphincter injuries increased from 0.5% in 1967 to 4.1% in 2004. After adjusting for demographic and other risk factors, as well as possible confounders, the increase of obstetric anal sphincter injuries persisted, although reduced (unadjusted OR 7.1; 95% confidence interval [CI] 6.8-7.4; adjusted OR 5.6; 95% CI 5.3-5.9). Obstetric anal sphincter injuries were significantly associated with maternal age 30 years or older, vaginal birth order of one, previous cesarean delivery, instrumental delivery, episiotomy, type 1 diabetes, gestational diabetes, induction of labor by prostaglandin, size of maternity unit, birth weight 3,500 g or more, head circumference 35 cm or more, and African or Asian country of birth. Risk of obstetric anal sphincter injuries considerably increased in Norway in 1967 to 2004. Changes in the risk factors studied could only partially explain this increase. II.

0 comments Cited 46 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

Journal ID (nlm-ta): BMJ Open

Journal ID (iso-abbrev): BMJ Open

Journal ID (hwp): bmjopen

Journal ID (publisher-id): bmjopen

Title: BMJ Open

Publisher: BMJ Publishing Group (BMA House, Tavistock Square, London, WC1H 9JR )

ISSN (Electronic): 2044-6055

Publication date (Print): 2012

Publication date Collection: 2012

Publication date (Electronic): 17 October 2012

Volume: 2

Issue: 5

Electronic Location Identifier: e001649

Affiliations

[1 ]Department of Obstetrics, Oslo University Hospital, Ullevål, Oslo, Norway

[2 ]Faculty of Medicine, University of Oslo, Oslo, Norway

[3 ]Women's Health and Perinatology Research Group, Department of Clinical Medicine, University of Tromsø, Tromsø, Norway

[4 ]Unit of Biostatistics and Epidemiology, Oslo University Hospital, Oslo, Norway

[5 ]Department of Gynaecology, Oslo University Hospital, Ullevål, Oslo, Norway

Author notes

[Correspondence to ] Dr Katariina Laine; kattiksen@ 123456yahoo.no

Article

Publisher ID: bmjopen-2012-001649

DOI: 10.1136/bmjopen-2012-001649

PMC ID: 3488722

PubMed ID: 23075573

SO-VID: bbe3c0bc-1c2e-41ac-bd83-885ed82a7789

Copyright © © 2012, Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

License:

This is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: http://creativecommons.org/licenses/by-nc/2.0/ and http://creativecommons.org/licenses/by-nc/2.0/legalcode.

Incidence of obstetric anal sphincter injuries after training to protect the perineum: cohort study

Read this article at

Abstract

Objective

Design

Setting

Participants

Primary and secondary outcome measures

Results

Conclusions

Related collections

RNA drug delivery

Most cited references 28

A multicenter interventional program to reduce the incidence of anal sphincter tears.

A randomised controlled trial of care of the perineum during second stage of normal labour.

Trends in risk factors for obstetric anal sphincter injuries in Norway.

Author and article information

Journal

Affiliations

Author notes

Article

History

Categories

Comments

Comment on this article

Similar content 319

Cited by 31

Most referenced authors 188