Bed Rest With a Short Cervix on Preterm Birth (BEWISE)

BEWISE - Bed Rest With a Short Cervix on Preterm Birth

Maternal AR has long been used to prevent PTB. However, definitions of AR vary widely, ranging from complete bed rest to partial limitation of physical activity for one or more hours daily.

The use of maternal AR to prevent preterm birth is largely based on observational evidence linking strenuous physical activity to an increased risk of preterm birth, and the assumption that reduced activity may decrease myometrial activity. However, the existing evidence on the clinical effects of AR remains limited and has not demonstrated a reduction in preterm birth or a delay in deliv-ery. In contrast, some studies suggest a potential increase in preterm birth following AR and instead significant adverse maternal and fetal effects.

The overall aim of this study is to compare gestational age at birth in women with a short cervix who are prescribed AR compared with women with a short cervix who are not prescribed AR (NAR).

The primary hypothesis is that NAR is non-inferior to AR in prolonging pregnancy in women with a short cervix.

Secondary hypotheses are that, compared with AR, NAR is associated with higher level of physical activity, lower risk of maternal depression, and reduced risk of loss of maternal bone mineral density.

Through the BEWISE study, we wish to implement a change in the Danish national clinical practice regarding AR from recommending AR in risk groups (current practice) to no longer recommending AR as part as routine care (new practice). We will evaluate this change in clinical practice by prospectively collecting data from women both before and after implementation of the new recommendation. The transition from AR to NAR will be implemented sequentially in each Danish region using a randomised stepped-wedge (SW) cluster design, with each region constituting a cluster. The order in which regions transition is determined by randomisation. Each region will adopt the new recommendation at 3-month intervals, resulting in full national transition from AR to NAR within 12 months Eligible participants are pregnant women in gestational age 20+0 to 33+6 and cervical length < 25 mm in singleton pregnancies and < 30 mm in multiple pregnancies. Participants must be above 18 years of age and be able to read and understand Danish or English. There are no exclusion criteria.

The primary outcome is gestational age in days (continuous).

Study Overview

• Status: Not yet recruiting
• Conditions: Physical Activity; Premature Birth; Pregnancy Complications; Depression, Postpartum; Preterm Birth; Obstetric Labor, Premature; Pregnancy Outcome; Cervical Insufficiency; Uterine Cervical Incompetence; Immobilization; Bone Density; Infant, Premature; Bed Rest
• Intervention / Treatment: Behavioral: Activity Restriction; Behavioral: No Activity Restriction

• Study Type: Interventional
• Enrollment (Estimated): 6000
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Kirsten Bünemann, Medical Doctor, PhD-student; Phone Number: +45 40329849; Email: kirsten.bunemann@clin.au.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Pregnant women with gestational age 20+0 to 33+6

• Cervical length < 25 mm in singleton pregnancies and < 30 mm in multiple pregnancies
• Above 18 years of age
• Reads and understands Danish or English

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Sequential Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Activity Restriction; The comparison arm reflects current Danish clinical practice in each participating region. According to national recommendations, AR is indicated before GA 28+0, with the level of restriction determined by cervical length and clinical context. In singleton pregnancies with a cervix <10 mm in singleton/<15 mm in twins, strict AR is prescribed, defined as bed rest with only toilet allowance. In addition, thrombosis prophylaxis (Low Molecular Weight Heparin and compression stockings) is initiated in cases of strict AR. In women with a cervix of 10-14 mm in singletons/15-20 mm in twins, or in cases of PPROM with a cervix <25 mm, moderate AR is prescribed, defined as 2-8 hours of daily bed rest. The regimen is continued until 28 weeks of gestation.	Behavioral: Activity Restriction; Recommendation to restrict physical activity in pregnant women with a short cervix. This may include increased rest or bed rest according to local clinical practice.; Other Names: AR; Bed Rest
Experimental: No Activity Restriction; The intervention consists of a recommendation of NAR during pregnancy. No general or graded restrictions on daily activities are advised, and cervical length is not an indication for activity limitation, in line with current evidence. The NAR recommendation is supported by a pragmatic clinical guidance. Women are advised to avoid activities that provoke pain, increase uterine contractions, or worsen pelvic pressure. Decisions regarding hospital admission or sick leave are based on individual clinical assessment rather than cervical length. Specific advice may be provided when clinically indicated. Women are generally advised to avoid heavy weight-bearing exercise and lifting of objects exceeding approximately 10 kg. Otherwise, no specific restrictions on physical activity are imposed, provided that activities do not provoke symptoms such as pain, increased uterine contractions, or pelvic pressure. Sexual activity may be ad-dressed on an individual basis following clinical assessment.	Behavioral: No Activity Restriction; Recommendation to continue normal daily activity in pregnant women with a short cervix, without restricting physical activity.; Other Names: Activity; No Bed Rest; NAR

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gestational age at birth	Gestational age at birth measured in completed days of pregnancy. This is calculated based on the estimated due date from ultrasound (crown-rump lenght <14weeks).	At birth (from inclusion until delivery)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Birth before 37 weeks of gestation		At birth
Gestational age at birth, pooled	14+0-21+6 weeks; 22+0-27+6 weeks; 28+0-31+6 weeks; 32+0-36+6 weeks; Birth after 37+0 weeks of gestation	At birth (from inclusion until delivery)
Latency from inclusion to birth (days)		At birth (from inclusion until delivery)
Onset of birth	Spontaneous; Induction; Caesarean section	At birth (from inclusion until delivery)
Mode of birth	Vaginal; Assisted vaginal; Planned caesarean section; Non planned caesarean section	At birth (from inclusion until delivery)
- Non-occipital presentation		At birth (from inclusion until delivery)
Interventions during birth	Oxytocin-infusion; Epidural anaesthesia	At birth (from inclusion until delivery)
Degree of birth tear	No tear; 1. or 2. degree tear; 3. or 4. degree tear	At birth (from inclusion until delivery)
Maternal serious morbidity	Admission to an intensive care unit or a unit providing 24-hour medical supervision, mechanical ventilation, or continuous vasoactive drug support at any time during pregnancy and postpartum due to pregnancy- or childbirth-related complications	From inclusion to 42 days after delivery
Umbilical cord arterial pH		At birth (from inclusion until delivery)
EPDS depression score		From inclusion to 8 weeks after due date
Bone turnover marker level	Procollagen type 1 N-propeptide (PINP); Carboxy-terminal telopeptide of type I collagen (CTX)	At inclusion and after 4 and 8 weeks.
Lumbar spine Z-score		12 months after stopped breastfeeding
Data from SENS activity tracker	Step count Time in supine position	At birth (from inclusion until delivery)
Neonatal mortality		At birth (from inclusion until delivery)
Fetal loss		At birth (from inclusion until delivery)
Birth weight		At birth (from inclusion until delivery)
Neonatal admission, days		From inclusion until discharge or 44 postmenstrual weeks
CNS morbidity	Intraventricular haemorrhage grade III or IV, Periventricular leukomalacia	From inclusion until discharge or 44 postmenstrual weeks
Gastrointestinal morbidity	Necrotizing enterocolitis (NEC) requiring surgery (Bell's stage 3), Spontaneous intestinal perfo-ration (SIP) requiring surgical treatment	From inclusion until discharge or 44 postmenstrual weeks
Respiratory support	Mechanical ventilation or non-invasive ventilation (NIV)	From inclusion until discharge or 44 postmenstrual weeks
Respiratory distress syndrome (RDS)		From inclusion until discharge or 44 postmenstrual weeks
Early onset infection	Definition: >5 days of i.v. antibiotics where the treatment starts within the first week after delivery.	From inclusion to 5 days after birth
Apgar score at 5 minutes		At birth (from inclusion until delivery)

Collaborators and Investigators

• Sponsor: Julie Glavind
• Collaborators: Odense University Hospital; Zealand University Hospital; Aarhus University Hospital; Rigshospitalet, Denmark; Aalborg University Hospital; University of Aberdeen
• Investigators: Principal Investigator: Julie Glavind, Senior Consultant, MD, PhD, Aarhus Univeristy Hospital, Department of Obstetrics and Gynecology

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): February 1, 2029
• Study Completion (Estimated): May 1, 2029

Study Registration Dates

• First Submitted: May 3, 2026
• First Submitted That Met QC Criteria: May 3, 2026
• First Posted (Actual): May 11, 2026

Study Record Updates

• Last Update Posted (Actual): May 11, 2026
• Last Update Submitted That Met QC Criteria: May 3, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Mental Disorders; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Obstetric Labor Complications; Uterine Diseases; Genital Diseases, Female; Mood Disorders; Uterine Cervical Diseases; Puerperal Disorders; Depressive Disorder; Abortion, Habitual; Abortion, Spontaneous; Behavior; Premature Birth; Pregnancy Complications; Depression, Postpartum; Obstetric Labor, Premature; Uterine Cervical Incompetence; Motor Activity; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Therapeutics; Exercise; Bed Rest
• Other Study ID Numbers: 16-0500-15; 4308-00216B (Other Grant/Funding Number: Independent Research Fund Denmark); 1-10-72-96-25 (Other Identifier: De Videnskabsetiske Komitéer For Region Midtjylland)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: IPD will be shared if possible according to GDPR and Danish legislation

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No