Missed obstetric anal sphincter injury following vaginal delivery in primiparous women

Prevalence and missed obstetric anal sphincter injury following vaginal delivery in primiparous women: a single center interventional study

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN18006760

Enrollment

800

Registered

2016-02-10

Start date

2015-08-31

Completion date

Unknown

Last updated

2017-12-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Obstetric anal sphincter injury (OASIS) Pregnancy and Childbirth

Interventions

Procedures The 3-D EAS (3-D imaging of the external anal sphincter) will be performed using a Flex Focus 500 Ultrasound scanner (BK Medical, Denmark) with a 8838 axial endoscopic probe. All the midwi

Eligibility

Sex/Gender

Female

Inclusion criteria

Inclusion criteria: All primiparous women who deliver vaginally at Östersunds hospital during the study-period

Exclusion criteria

Exclusion criteria: 1. Prior history of faecal incontinence 2. Anal sphincter surgery 3. Other known sphincter insufficiency

Design outcomes

Primary

Measure	Time frame
Current primary outcome measures as of 30/11/2017: To assess the prevalence of OASIS and compare the clinical examination with inspection and digital anal palpation to 3-D EAS, to examine the number of OASIS missed at clinical post-partum examination. Shortly after delivery the patients will be examined by the midwife or in eligible cases a doctor who will inspect the vagina and make a digital anal examination. Their findings will be documented in a study protocol classifying the degree of the tear according to the WHO- classification. The anal ultrasound will then be performed by an independent midwife clueless to the findings in the digital examination. The EAS finding will be saved in a data base for revision and classification within 2 weeks. After 12 weeks, a new 3D-EAS recording will be made by a mid-wife to make sure no sphincter tears are missed because of oedema or bleeding, which may be present immediately post partum and make the image more difficult to analyse. Previous primary outcome measures: To compare the clinical examination with inspection and digital anal palpation to 3-D EAS, to examine the number of OASIS missed at clinical post-partum examination. Shortly after delivery the patients will be examined by the midwife or in eligible cases a doctor who will inspect the vagina and make a digital anal examination. Their findings will be documented in a study protocol classifying the degree of the tear according to the WHO- classification. The anal ultrasound will then be performed by an independent midwife clueless to the findings in the digital examination. The EAS finding will be saved in a data base for revision and classification within 2 weeks. Ultrasound findings will be classified using the Starck scoring system for sphincter defects. After 12 weeks, a new 3D-EAS recording will be made by a mid-wife to make sure no sphincter tears are missed because of oedema or bleeding, which may be present immediately post partum and make the image more di	—

Measure

Time frame

Current primary outcome measures as of 30/11/2017: To assess the prevalence of OASIS and compare the clinical examination with inspection and digital anal palpation to 3-D EAS, to examine the number of OASIS missed at clinical post-partum examination. Shortly after delivery the patients will be examined by the midwife or in eligible cases a doctor who will inspect the vagina and make a digital anal examination. Their findings will be documented in a study protocol classifying the degree of the tear according to the WHO- classification. The anal ultrasound will then be performed by an independent midwife clueless to the findings in the digital examination. The EAS finding will be saved in a data base for revision and classification within 2 weeks. After 12 weeks, a new 3D-EAS recording will be made by a mid-wife to make sure no sphincter tears are missed because of oedema or bleeding, which may be present immediately post partum and make the image more difficult to analyse. Previous primary outcome measures: To compare the clinical examination with inspection and digital anal palpation to 3-D EAS, to examine the number of OASIS missed at clinical post-partum examination. Shortly after delivery the patients will be examined by the midwife or in eligible cases a doctor who will inspect the vagina and make a digital anal examination. Their findings will be documented in a study protocol classifying the degree of the tear according to the WHO- classification. The anal ultrasound will then be performed by an independent midwife clueless to the findings in the digital examination. The EAS finding will be saved in a data base for revision and classification within 2 weeks. Ultrasound findings will be classified using the Starck scoring system for sphincter defects. After 12 weeks, a new 3D-EAS recording will be made by a mid-wife to make sure no sphincter tears are missed because of oedema or bleeding, which may be present immediately post partum and make the image more di

—

Secondary

Measure	Time frame
To examine risk factors for OASIS. Facts about the pregnancy, delivery and the new born will be collected, including gestation week at delivery, type of anaesthesia, delivery position, the use of instruments and/or episiotomy, induction of labour, augmentation of labour, weight and head-size of the infant, fetal presentation and APGAR score.	—

Countries

Sweden

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026