Prevalence of Obstetric Anal Sphincter Injury With a Reducing Episiotomy Rate

Anal Sphincter Injury Clinical Trial

Official title:

Prevalence of Obstetric Anal Sphincter Injury With a Reducing Episiotomy Rate

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05436171
• Other study ID #: CRE 2022.259
• Status: Recruiting
• Start date: August 11, 2022
• Est. completion date: May 31, 2023

Study information

• Verified date: August 2022
• Source: Chinese University of Hong Kong
• Contact: Yan Yan Lau
• Phone: 8525569 9272
• Email: yanyanlau[@]cuhk.edu.hk
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Obstetric anal sphincter injury (OASIS) is a serious complication of a vaginal delivery. High proportion of women, 40-59%, suffer from faecal incontinence (FI) after this type of injury.1-3 OASIS and FI have a negative impact on women's quality of life.4 The rate of elective caesarean section at second birth was much higher in women with OASIS at first birth compared with women without the injury (adjusted odds ratio 18.3, 95% CI 16.4-20.4).5 Primiparity has an increased risk of OASIS (odds ratio (OR) 2.39-8.34).6,7 Other factors are macrosomia and instrumental vaginal delivery.6,7 The role of episiotomy on OASIS has also been widely studied but there are controversial results.

There were around 500-7000 deliveries at Prince of Wales Hospital annually. Among them, 50-55% was nulliparous women. About 65 -70% of women had normal vaginal delivery and another 5-10% had instrumental delivery. There was a change from 'routine episiotomy' to a more restrictive use of episiotomy in normal vaginal delivery during the last 10 years, with a reduction of rate of episiotomy from 90% to about 50% (from Dept.'s internal audit). The objective of this study is to evaluate the prevalence of OASIS in the era of a reduction of episiotomy.

Description:

Obstetric anal sphincter injury (OASIS) is a serious complication of a vaginal delivery. High proportion of women, 40-59%, suffer from faecal incontinence (FI) after this type of injury.1-3 OASIS and FI have a negative impact on women's quality of life.4 The rate of elective caesarean section at second birth was much higher in women with OASIS at first birth compared with women without the injury (adjusted odds ratio 18.3, 95% CI 16.4-20.4).5 Primiparity has an increased risk of OASIS (odds ratio (OR) 2.39-8.34).6,7 Other factors are macrosomia and instrumental vaginal delivery.6,7 The role of episiotomy on OASIS has also been widely studied but there are controversial results.

Episiotomy is a surgical enlargement of the vaginal orifice by an incision to the perineum during the last part of the second stage of labour or delivery.8 It is accepted that episiotomy facilitates delivery, prevents perineal lacerations and undue stretching of the pelvic floor.9 It is also believed that an episiotomy is easier to repair and heals better than a tear.10 Mediolateral episiotomy is the most frequently used type of episiotomy in Hong Kong. Some obstetric units perform episiotomy more liberally on a routine basis; while others adopt a more restrictive policy. Cochrane review identified eight randomized controlled trials (RCT) comparing routine episiotomy and restrictive episiotomy. 9,10-17 The restrictive use of episiotomy shows a lower risk of severe perineal trauma (relative risk (RR) 0.67, 95% CI 0.49-0.91), posterior perineal trauma (RR 0.88, 95% CI 0.84-0.92), need for suturing perineal trauma (RR 0.71, 95% CI 0.61-0.81), and healing complications at seven days (RR 0.69, 95% CI 0.56-0.85).13 No difference is shown in the incidence of major outcomes such as severe vaginal and perineal trauma (when both vaginal and perineal trauma are counted) nor in pain, dyspareunia or urinary incontinence. However, the restrictive use of episiotomy has an increased risk of anterior perineal trauma (RR 1.84, 95% CI 1.61-2.10).13 Therefore, it is not advised to practice routine episiotomy.

From a large retrospective studies conducted in Caucasian countries, mediolateral episiotomy has been shown to protect women from OASIS (OR 0.21-0.54). 6,7,18 Besides, there was also evidence showing that Asian women delivered in Caucasian countries with a low episiotomy rate had a high risk of OASIS.19,20 Furthermore, ethnical difference in pelvic connective tissues have been reported.21 And pregnant Chinese women has been shown to smaller genital hiatus and less mobility of pelvic organs than pregnant Caucasian women.22 This may lead to a different outcome in perineal trauma in Asian women with or without episiotomy during vaginal delivery.

There were around 500-7000 deliveries at Prince of Wales Hospital annually. Among them, 50-55% was nulliparous women. About 65-70% of women had normal vaginal delivery and another 5-10% had instrumental delivery. There was a change from 'routine episiotomy' to a more restrictive use of episiotomy in normal vaginal delivery during the last 10 years, with a reduction of rate of episiotomy from 90% to about 50% (from Dept.'s internal audit). The objective of this study is to evaluate the prevalence of OASIS in the era of a reduction of episiotomy. This would help inform obstetricians and midwives if there is any change in rate of OASIS and the relationship with episiotomy. The information would be useful to counsel our patients.

The protocol of current study complies with Declaration of Helsinki.

The HA CMS OBSCIS is the electronic system that have collected the demographic, pregnancy, delivery and postnatal data of pregnant women. The data was entered by midwives and obstetricians during all consultations and admission of delivery of all pregnant women.

In this study, the following information will be retrieved from the CMS OBSCIS database for all delivery conducted from 2011 to 2021.

1. Demographic data: age, parity, body weight and height

2. Past obstetric history (if any): mode of delivery, birthweight and sex of infant, use of episiotomy

3. Delivery data: gestation at delivery, need of induction of labour, analgesics during labour, duration of labour, mode of delivery, use of episiotomy, any perineal tear, blood loss during delivery, need of transfusion, wound complication, duration of hospital stay; and infant's birthweight, sex and apgar score

4. For women with OASIS: the method of repair, the symptom of pelvic floor disorders, such as faecal or flatal incontinence, urinary incontinence, symptoms of prolapse after the delivery.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 6700
• Est. completion date: May 31, 2023
• Est. primary completion date: May 31, 2023
• Gender: Female
• Age group: 18 Years to 99 Years

Eligibility

Inclusion Criteria:

• All deliveries conducted from 2011 to 2021 in Prince of Wales Hospital

Exclusion Criteria:

• Deliveries with Caesarean Section

Related Conditions & MeSH terms

• Anal Sphincter Injury
• Wounds and Injuries

Intervention

Other:
• No intervention
No intervention

Locations

Country	Name	City	State
Hong Kong	The Chinese University of Hong Kong	Hong Kong

Sponsors (1)

Lead Sponsor	Collaborator
Chinese University of Hong Kong

Country where clinical trial is conducted

Hong Kong, 

References & Publications (22)

Aukee P, Sundström H, Kairaluoma MV. The role of mediolateral episiotomy during labour: analysis of risk factors for obstetric anal sphincter tears. Acta Obstet Gynecol Scand. 2006;85(7):856-60. — View Citation

Carroli G, Mignini L. Episiotomy for vaginal birth. Cochrane Database Syst Rev. 2009 Jan 21;(1):CD000081. doi: 10.1002/14651858.CD000081.pub2. Review. Update in: Cochrane Database Syst Rev. 2017 Feb 08;2:CD000081. — View Citation

Cheung RY, Shek KL, Chan SS, Chung TK, Dietz HP. Pelvic floor muscle biometry and pelvic organ mobility in East Asian and Caucasian nulliparae. Ultrasound Obstet Gynecol. 2015 May;45(5):599-604. doi: 10.1002/uog.14656. Epub 2015 Apr 6. — View Citation

Dannecker C, Hillemanns P, Strauss A, Hasbargen U, Hepp H, Anthuber C. Episiotomy and perineal tears presumed to be imminent: randomized controlled trial. Acta Obstet Gynecol Scand. 2004 Apr;83(4):364-8. — View Citation

Davies-Tuck M, Biro MA, Mockler J, Stewart L, Wallace EM, East C. Maternal Asian ethnicity and the risk of anal sphincter injury. Acta Obstet Gynecol Scand. 2015 Mar;94(3):308-15. doi: 10.1111/aogs.12557. Epub 2015 Jan 10. — View Citation

de Leeuw JW, Struijk PC, Vierhout ME, Wallenburg HC. Risk factors for third degree perineal ruptures during delivery. BJOG. 2001 Apr;108(4):383-7. — View Citation

Edozien LC, Gurol-Urganci I, Cromwell DA, Adams EJ, Richmond DH, Mahmood TA, van der Meulen JH. Impact of third- and fourth-degree perineal tears at first birth on subsequent pregnancy outcomes: a cohort study. BJOG. 2014 Dec;121(13):1695-703. doi: 10.1111/1471-0528.12886. Epub 2014 Jul 9. — View Citation

Eltorkey MM, Al Nuaim MA, Kurdi AM, Sabagh TO, Clarke F. Episiotomy, elective or selective: a report of a random allocation trial. Journal of Obstetrics and Gynaecology 1994;14:317-320.

Grobman WA, Bailit JL, Rice MM, Wapner RJ, Reddy UM, Varner MW, Thorp JM Jr, Leveno KJ, Caritis SN, Iams JD, Tita ATN, Saade G, Rouse DJ, Blackwell SC, Tolosa JE, VanDorsten JP; Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units (MFMU) Network. Racial and ethnic disparities in maternal morbidity and obstetric care. Obstet Gynecol. 2015 Jun;125(6):1460-1467. doi: 10.1097/AOG.0000000000000735. — View Citation

Harrison RF, Brennan M, North PM, Reed JV, Wickham EA. Is routine episiotomy necessary? Br Med J (Clin Res Ed). 1984 Jun 30;288(6435):1971-5. — View Citation

Hauck YL, Lewis L, Nathan EA, White C, Doherty DA. Risk factors for severe perineal trauma during vaginal childbirth: a Western Australian retrospective cohort study. Women Birth. 2015 Mar;28(1):16-20. doi: 10.1016/j.wombi.2014.10.007. Epub 2014 Dec 1. — View Citation

House MJ, Cario G, Jones MH. Episiotomy and the perineum: a random controlled trial. J Obstet Gynaecol 1986;7:107-110

Klein MC, Gauthier RJ, Jorgensen SH, Robbins JM, Kaczorowski J, Johnson B, Corriveau M, Westreich R, Waghorn K, Gelfand MM, et al. Does episiotomy prevent perineal trauma and pelvic floor relaxation? Online J Curr Clin Trials. 1992 Jul 1;Doc No 10:[6019 words; 65 paragraphs]. Erratum in: Online J Curr Clin Trials 1992 Sep 12;Doc No 20:[54 words; 1. — View Citation

Norderval S, Nsubuga D, Bjelke C, Frasunek J, Myklebust I, Vonen B. Anal incontinence after obstetric sphincter tears: incidence in a Norwegian county. Acta Obstet Gynecol Scand. 2004 Oct;83(10):989-94. — View Citation

Rodriguez A, Arenas EA, Osorio AL, Mendez O, Zuleta JJ. Selective vs routine midline episiotomy for the prevention of third- or fourth-degree lacerations in nulliparous women. Am J Obstet Gynecol. 2008 Mar;198(3):285.e1-4. doi: 10.1016/j.ajog.2007.11.007. Epub 2008 Jan 25. — View Citation

Routine vs selective episiotomy: a randomised controlled trial. Argentine Episiotomy Trial Collaborative Group. Lancet. 1993 Dec 18-25;342(8886-8887):1517-8. — View Citation

Sangalli MR, Floris L, Faltin D, Weil A. Anal incontinence in women with third or fourth degree perineal tears and subsequent vaginal deliveries. Aust N Z J Obstet Gynaecol. 2000 Aug;40(3):244-8. — View Citation

Sleep J, Grant A, Garcia J, Elbourne D, Spencer J, Chalmers I. West Berkshire perineal management trial. Br Med J (Clin Res Ed). 1984 Sep 8;289(6445):587-90. — View Citation

Sultan AH, Kamm MA, Hudson CN, Bartram CI. Third degree obstetric anal sphincter tears: risk factors and outcome of primary repair. BMJ. 1994 Apr 2;308(6933):887-91. — View Citation

Thacker SB, Banta HD. Benefits and risks of episiotomy: an interpretative review of the English language literature, 1860-1980. Obstet Gynecol Surv. 1983 Jun;38(6):322-38. Review. — View Citation

Tucker J, Clifton V, Wilson A. Teetering near the edge; women's experiences of anal incontinence following obstetric anal sphincter injury: an interpretive phenomenological research study. Aust N Z J Obstet Gynaecol. 2014 Aug;54(4):377-81. doi: 10.1111/ajo.12230. — View Citation

Zacharin R. "A Chinese anatomy" - the pelvic supporting tissues of the Chinese and Occidental female compared and contrasted. Aust N Z J Obstet Gynaecol 1977;17:1-11.

* Note: There are 22 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Prevalence of obstetric anal sphincter injury (third or fourth degree tear) detected clinically immediately after delivery	Prevalence of obstetric anal sphincter injury (third or fourth degree tear) detected clinically immediately after delivery	Immediately after delivery
Secondary	The factors associated with OASIS	Linear regression will be used to assess the correlations between factors e.g. mode of delivery, episiotomy, perineal/vaginal tear, duration of labour, birthweight and OASIS. Univariate and multivariate analysis will be used to look for potential factors of OASIS.	Immediately after delivery