Delivery mode, levator avulsion and obstetric anal sphincter injury: A cross-sectional study 20 years after childbirth

Sylvia Lin, Ixora Kamisan @ Atan, Hans Peter Dietz, Peter Herbison, Peter Donald Wilson

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

BACKGROUND: Levator ani muscle (LAM) and anal sphincter injuries are common after vaginal birth and are associated with pelvic organ prolapse and anal incontinence. AIMS: Our objective was to investigate long-term association between delivery mode, LAM avulsion and obstetric anal sphincter injuries (OASIS) in women at least 20 years after their first birth. METHODS: All women recruited at 'index birth' of the Dunedin (New Zealand) arm of ProLong (PROlapse and incontinence LONG-term research) Study, were invited to have translabial and transperineal ultrasound assessment of LAM and anal sphincters. Post-processing analysis of imaging data was performed blinded against delivery data. Statistical analysis was performed using the χ2 test and results are expressed as odds ratios (OR). RESULTS: Of the initial 1250 participants, 196 women returned for examination. Mean age was 50.8 years with a mean body mass index of 27.6 and median parity was three. They were seen on average 23 years after their first delivery. Four data sets were unavailable and one declined ultrasound assessment, leaving 191 for analysis. LAM avulsion was diagnosed in 29 (15.2%), and 24 women (12.6%) had significant anal sphincter defect. LAM avulsion was associated with forceps delivery (OR 2.45, 95% CI 1.04-5.80, P = 0.041). Forceps conveyed a greater risk of OASIS (21%) compared to a spontaneous vaginal delivery (11%) but did not reach statistical significance. CONCLUSIONS: Forceps delivery is associated with long-term injurious effect on pelvic floor structures. Discussions of the long-term negative impact of pelvic floor structures and their functions are necessary to achieve an informed consent toward an operative vaginal delivery.

Original languageEnglish
Pages (from-to)590-596
Number of pages7
JournalThe Australian & New Zealand journal of obstetrics & gynaecology
Volume59
Issue number4
DOIs
Publication statusPublished - 1 Aug 2019

Fingerprint

Anal Canal
Obstetrics
Cross-Sectional Studies
Parturition
Wounds and Injuries
Muscles
Surgical Instruments
Pelvic Floor
Odds Ratio
Pelvic Organ Prolapse
Birth Order
Prolapse
Parity
Informed Consent
New Zealand
Body Mass Index
Arm

Keywords

  • anal sphincter injury
  • delivery mode
  • forceps delivery
  • instrumental delivery
  • levator ani avulsion

ASJC Scopus subject areas

  • Obstetrics and Gynaecology

Cite this

Delivery mode, levator avulsion and obstetric anal sphincter injury : A cross-sectional study 20 years after childbirth. / Lin, Sylvia; Kamisan @ Atan, Ixora; Dietz, Hans Peter; Herbison, Peter; Wilson, Peter Donald.

In: The Australian & New Zealand journal of obstetrics & gynaecology, Vol. 59, No. 4, 01.08.2019, p. 590-596.

Research output: Contribution to journalArticle

@article{efcb4c48ce7143f7a408a36d7c840d07,
title = "Delivery mode, levator avulsion and obstetric anal sphincter injury: A cross-sectional study 20 years after childbirth",
abstract = "BACKGROUND: Levator ani muscle (LAM) and anal sphincter injuries are common after vaginal birth and are associated with pelvic organ prolapse and anal incontinence. AIMS: Our objective was to investigate long-term association between delivery mode, LAM avulsion and obstetric anal sphincter injuries (OASIS) in women at least 20 years after their first birth. METHODS: All women recruited at 'index birth' of the Dunedin (New Zealand) arm of ProLong (PROlapse and incontinence LONG-term research) Study, were invited to have translabial and transperineal ultrasound assessment of LAM and anal sphincters. Post-processing analysis of imaging data was performed blinded against delivery data. Statistical analysis was performed using the χ2 test and results are expressed as odds ratios (OR). RESULTS: Of the initial 1250 participants, 196 women returned for examination. Mean age was 50.8 years with a mean body mass index of 27.6 and median parity was three. They were seen on average 23 years after their first delivery. Four data sets were unavailable and one declined ultrasound assessment, leaving 191 for analysis. LAM avulsion was diagnosed in 29 (15.2{\%}), and 24 women (12.6{\%}) had significant anal sphincter defect. LAM avulsion was associated with forceps delivery (OR 2.45, 95{\%} CI 1.04-5.80, P = 0.041). Forceps conveyed a greater risk of OASIS (21{\%}) compared to a spontaneous vaginal delivery (11{\%}) but did not reach statistical significance. CONCLUSIONS: Forceps delivery is associated with long-term injurious effect on pelvic floor structures. Discussions of the long-term negative impact of pelvic floor structures and their functions are necessary to achieve an informed consent toward an operative vaginal delivery.",
keywords = "anal sphincter injury, delivery mode, forceps delivery, instrumental delivery, levator ani avulsion",
author = "Sylvia Lin and {Kamisan @ Atan}, Ixora and Dietz, {Hans Peter} and Peter Herbison and Wilson, {Peter Donald}",
year = "2019",
month = "8",
day = "1",
doi = "10.1111/ajo.12948",
language = "English",
volume = "59",
pages = "590--596",
journal = "Australian and New Zealand Journal of Obstetrics and Gynaecology",
issn = "0004-8666",
publisher = "Wiley-Blackwell",
number = "4",

}

TY - JOUR

T1 - Delivery mode, levator avulsion and obstetric anal sphincter injury

T2 - A cross-sectional study 20 years after childbirth

AU - Lin, Sylvia

AU - Kamisan @ Atan, Ixora

AU - Dietz, Hans Peter

AU - Herbison, Peter

AU - Wilson, Peter Donald

PY - 2019/8/1

Y1 - 2019/8/1

N2 - BACKGROUND: Levator ani muscle (LAM) and anal sphincter injuries are common after vaginal birth and are associated with pelvic organ prolapse and anal incontinence. AIMS: Our objective was to investigate long-term association between delivery mode, LAM avulsion and obstetric anal sphincter injuries (OASIS) in women at least 20 years after their first birth. METHODS: All women recruited at 'index birth' of the Dunedin (New Zealand) arm of ProLong (PROlapse and incontinence LONG-term research) Study, were invited to have translabial and transperineal ultrasound assessment of LAM and anal sphincters. Post-processing analysis of imaging data was performed blinded against delivery data. Statistical analysis was performed using the χ2 test and results are expressed as odds ratios (OR). RESULTS: Of the initial 1250 participants, 196 women returned for examination. Mean age was 50.8 years with a mean body mass index of 27.6 and median parity was three. They were seen on average 23 years after their first delivery. Four data sets were unavailable and one declined ultrasound assessment, leaving 191 for analysis. LAM avulsion was diagnosed in 29 (15.2%), and 24 women (12.6%) had significant anal sphincter defect. LAM avulsion was associated with forceps delivery (OR 2.45, 95% CI 1.04-5.80, P = 0.041). Forceps conveyed a greater risk of OASIS (21%) compared to a spontaneous vaginal delivery (11%) but did not reach statistical significance. CONCLUSIONS: Forceps delivery is associated with long-term injurious effect on pelvic floor structures. Discussions of the long-term negative impact of pelvic floor structures and their functions are necessary to achieve an informed consent toward an operative vaginal delivery.

AB - BACKGROUND: Levator ani muscle (LAM) and anal sphincter injuries are common after vaginal birth and are associated with pelvic organ prolapse and anal incontinence. AIMS: Our objective was to investigate long-term association between delivery mode, LAM avulsion and obstetric anal sphincter injuries (OASIS) in women at least 20 years after their first birth. METHODS: All women recruited at 'index birth' of the Dunedin (New Zealand) arm of ProLong (PROlapse and incontinence LONG-term research) Study, were invited to have translabial and transperineal ultrasound assessment of LAM and anal sphincters. Post-processing analysis of imaging data was performed blinded against delivery data. Statistical analysis was performed using the χ2 test and results are expressed as odds ratios (OR). RESULTS: Of the initial 1250 participants, 196 women returned for examination. Mean age was 50.8 years with a mean body mass index of 27.6 and median parity was three. They were seen on average 23 years after their first delivery. Four data sets were unavailable and one declined ultrasound assessment, leaving 191 for analysis. LAM avulsion was diagnosed in 29 (15.2%), and 24 women (12.6%) had significant anal sphincter defect. LAM avulsion was associated with forceps delivery (OR 2.45, 95% CI 1.04-5.80, P = 0.041). Forceps conveyed a greater risk of OASIS (21%) compared to a spontaneous vaginal delivery (11%) but did not reach statistical significance. CONCLUSIONS: Forceps delivery is associated with long-term injurious effect on pelvic floor structures. Discussions of the long-term negative impact of pelvic floor structures and their functions are necessary to achieve an informed consent toward an operative vaginal delivery.

KW - anal sphincter injury

KW - delivery mode

KW - forceps delivery

KW - instrumental delivery

KW - levator ani avulsion

UR - http://www.scopus.com/inward/record.url?scp=85070906611&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85070906611&partnerID=8YFLogxK

U2 - 10.1111/ajo.12948

DO - 10.1111/ajo.12948

M3 - Article

C2 - 30793279

AN - SCOPUS:85070906611

VL - 59

SP - 590

EP - 596

JO - Australian and New Zealand Journal of Obstetrics and Gynaecology

JF - Australian and New Zealand Journal of Obstetrics and Gynaecology

SN - 0004-8666

IS - 4

ER -