The SWEEP Trial: a Randomized Controlled Trial

Background and Objective:

Membrane sweeping is a simple mechanical procedure used at term to promote spontaneous onset of labor by stimulating local prostaglandin release. Although it is widely used and generally considered safe, evidence for its effectiveness is limited and of low certainty. The SWEEP trial is a multicenter randomized controlled trial designed to address this gap by investigating whether serial membrane sweeping starting between GA 39+5 and 40+2 increases the likelihood of spontaneous labor before GA 41+3 compared to no membrane sweeping.

Study design:

This is a pragmatic, open-label, multicenter, randomized controlled trial conducted in public antenatal clinics in Denmark. A total of 1536 pregnant women with low-risk, singleton pregnancies will be randomized between GA 39+5 and 40+2 to either: No membrane sweeping, or serial membrane sweeping with 2-3 days interval, max. three times.

Intervention and Procedures:

If possible, the first membrane sweeping will be performed during the routine antenatal visit at term. If not feasible, a separate consultation will be arranged. Two additional appointments will be scheduled as needed. Membrane sweeping is performed by inserting one or two fingers through the cervix and rotating them 2-5 times to separate the fetal membranes from the lower uterine segment. If the cervix is closed, cervical massage is performed externally with circular motions for approximately 15 seconds.

The intervention will continue until spontaneous labor begins or a maximum of three sweepings have been performed.

Participants in the control group will receive routine midwifery care but will be asked to avoid membrane sweeping until at least GA 41+3, unless medically indicated.

Inclusion criteria:

Singleton pregnant women at term with a fetus in cephalic presentation and an intended vaginal delivery.

Exclusion criteria:

\< 18 years of age Unable to speak and understand Danish Gestational age not determined by Crown-Rump-Length Previous cesarean section Ruptured membranes Painful contractions Vaginal bleeding more than bloody discharge Membrane sweeping performed within the last two weeks Already scheduled IOL or any known indication for IOL at or prior to GA 41+3 based on local or national guidelines Known low-lying placenta (placenta located \<3 cm from the internal orifice verified by transvaginal ultrasound)

Outcomes:

The primary outcome is birth \< GA 41+3 with spontaneous onset of labor.

Key secondary outcomes:

Risks and Side Effects:

There are no known serious risks associated with membrane sweeping for either the mother or baby.

Common and mild side effects may include:

Discomfort or mild pain during the procedure (the procedure can be stopped at any time upon request) Light spotting or brown discharge Braxton Hicks contractions

Informed Consent and Ethical Considerations:

Participants will receive both oral and written information in accordance with national and international ethical guidelines. Consent is obtained digitally via the REDCap platform using secure electronic signature technology.

Participants may withdraw consent at any time without consequence. All data are processed in accordance with the Danish Health Act and applicable GDPR regulations.

The study has been approved by the Regional Committees on Health Research Ethics for Central Denmark Region (journal number: 1-10-72-82-24 ) in accordance with Danish law and the Declaration of Helsinki.

Funding:

Funding for the trial is donated by:

Sundhedsdonationer from the Danish health insurance "danmark" with 7,000,000 DKK, The Health Research Foundation of Central Denmark Region with 100,000 DKK The Danish Association of Midwives with 45,931 DKK.

Additional funds will be sought to cover running costs during the trial. The investigators have no financial interests in the funding organizations.

Dissemination:

Study results will be published in international peer-reviewed journals and made publicly accessible in accordance with transparency requirements.

• Undelivered at Gestational Age 41+3 [Time frame: From randomization until time of birth. Assessed at birth.]
• Gestational Age at Delivery [Time frame: From randomization until time of birth. Assessed at birth]
• Randomization to Delivery Interval [Time frame: From date of randomization until the date of birth, assessed up to 21 days]
• Duration of Labor [Time frame: From onset of labor (self-reported contractions or spontaneous rupture of membranes) until time of birth.]
• Duration of Active Labor [Time frame: From active phase of labor to time of birth]
• Induction Of Labor (IOL) [Time frame: From date of randomization until time of birth. Assessed within 21 days.]
• Indication for Induction of Labor [Time frame: From date of randomization until time of birth. Assessed within 21 days.]
• Spontaneous Rupture of Membranes [Time frame: From date of randomization until time of birth. Assessed within 21 days.]
• Use of Oxytocin Augmentation [Time frame: From active phase of labor to time of birth]
• Intrapartum Temperature equal to or greater than 38.0 degrees Celsius [Time frame: From labor onset to time of birth]
• Epidural Analgesia During Labor [Time frame: From labor onset to time of birth]
• Mode of Delivery [Time frame: From onset of labor to time of birth]