Lateral Episiotomy or Not in Vacuum Assisted Delivery in Non-parous Women

Summary

Participation Requirements

Description

The study has started at Danderyd Hospital. Danderyd Hospital is a large teaching hospital affiliated to the Karolinska Institute in Stockholm, Sweden. South General Hospital in Stockholm, Uppsala University Hospital, Falun Hospital, Helsingborg Hospital, Växjö Hospital, Umeå University Hospital, an...

The study has started at Danderyd Hospital. Danderyd Hospital is a large teaching hospital affiliated to the Karolinska Institute in Stockholm, Sweden. South General Hospital in Stockholm, Uppsala University Hospital, Falun Hospital, Helsingborg Hospital, Växjö Hospital, Umeå University Hospital, and Gothenburg University Hospital Östra have joined the trial 2017-2019. Informed consent is collected from nulliparous women with a singelton, live fetus in cephalic presentation, with a planned vaginal delivery and without previous gynecological surgery due to incontinence or genital prolapse. Women can be approached at any time from gestational week 18 until delivery, unless they are in severe pain or discomfort, there is not enough time to consider the information, or any other reason not to obtain consent. The informed consent form is kept at the receiving research department and a note of consent/no consent is made in the obstetric medical file. At indication for vacuum extraction, the patient's consent is confirmed verbally and allocation is made by sealed opaque envelopes on the vacuum extraction equipment mobile cart. Randomization is performed 1:1 in random permuted blocks generated by an external organization (Karolinska Trial Alliance). Lateral episiotomy is performed according to the intervention description. A reduction of OASIS from 12.4% to 6.2% can be detected with 80% power and less than 5% risk of alpha-error (p<0.05) with 354 women in each group using Chi-square test comparing two independent proportions in a two-sided test (3% missing outcome). A smaller reduction is clinically valuable, although the risk-benefit relationship between receiving a prophylactic episiotomy and the chance of an intact perineum may limit the feasibility of a larger trial in a setting with a restrictive episiotomy policy. We have obtained ethical approval to randomise a total of 1400 women, which enables us to detect a reduction in OASIS rate at VE from 12.4% to 7.8% (p<0.05). We will perform an interim analysis in order to exclude an unethically large difference (p<0.01) in primary outcome or serious adverse events at 350 randomized women. Data is collected prospectively through Case Record Forms and the obstetric medical file Obstetrix (Cerner Sverige AB), which covers approximately 98% of deliveries with complete data, and the Swedish Pregnancy Register covering the whole of Sweden from 2015. Using a weblink, questionnaires from the national Perineal Tear Register, are sent out electronically for the follow-up of the study participants. In addition, questionnaires regarding birth satisfaction (BSS-R and CEQ 2.0) are sent at 8 weeks after delivery. Questionnaires regarding sexual function (FSFI and FSDS) and quality of life (Euro-QoL-5D) at delivery and after 12 months. A follow-up from registers regarding mode of delivery and prevalence of episiotomy and OASIS in subsequent births will be performed at 5 years and 10 years after the index birth. A substudy takes place in Stockholm, Uppsala, and Helsingborg, where included (randomized) women are examined at 6-12 months after delivery with 2D and 3D endovaginal and anal ultrasound to detect levator and sphincter injuries, measure episiotomy scars, establish POP-Q scores, and evaluate a new questionnaire for pelvic floor function after perineal tears. Another substudy takes place in Stockholm and Falun, where women who have been asked for consent (both affirmative and non-affirmative responders) as well as midwives who have tried to obtain consent, are invited to a qualitative interview study to explore the recruitment experience of women and midwives.

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