Preventing preterm birth in Chinese women with a short cervix in singleton pregnancies

ISRCTN ISRCTN18185477
DOI https://doi.org/10.1186/ISRCTN18185477
Secondary identifying numbers CRE-2008.375-T
Submission date
10/04/2012
Registration date
16/04/2012
Last edited
19/09/2014
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Pregnancy and Childbirth
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
The chance that a woman will go into labour and deliver before 34 weeks is about 1%, but in women with a short cervix the chance of premature birth before 34 weeks increases to 4 to 40%. The majority of babies born prematurely survive and develop normally. However, babies born before 34 weeks have a higher chance of dying soon after birth or becoming disabled than babies born at term. There is some evidence that in singleton pregnancies with a previous premature birth or a short cervix, the chance of premature birth may be reduced by using progesterone or performing cervical cerclage. However, there is no single best effective intervention that has been proven to prolong pregnancy in women at risk, and some forms of treatment like cervical cerclage may even impose risk to the mother and fetus. There is some evidence that in women at risk of preterm delivery, the use of a vaginal pessary reduces the chance of premature birth, but the evidence is weak and therefore this issue needs further investigation. The aim of this study is to determine the effect of a vaginal pessary on the incidence of preterm delivery in women with a short cervix.

Who can participate?
Chinese women found to have a short cervix (less than 25 mm) with a singleton pregnancy.

What does the study involve?
You will be randomly allocated to one of two groups, either the expectant management group or the pessary group. Irrespective to which group you are allocated to, we will see you in our clinic every four weeks and carry out ultrasound scans to examine the baby and measure the length of your cervix.

What are the possible benefits and risks of participating?
Previous studies using the pessary have shown no adverse effects on the baby. A few women may experience increased vaginal discharge but the pessary does not cause a vaginal infection. During your visits to the hospital we will ask you if you have developed any vaginal discharge. If you have such a discharge we will examine you to find out if you have an infection and treat you with the necessary antibiotics.

Where is the study run from?
The study is conducted by Department of Obstetrics and Gynaecology at the Chinese University of Hong Kong.

When is the study starting and how long is it expected to run for?
The study ran from October 2008 to February 2011.

Who is funding the study?
The primary study site is at Prince of Wales Hospital, Hong Kong.

Who is the main contact?
Dr Annie Hui
Tel: 2632 2211

Contact information

Dr Shuk Yi Annie Hui
Scientific

1E, Department of OG
Prince of Wales Hospital
Shatin, N.T.
-
-
Hong Kong

Study information

Study designRandomized controlled single-centre trial
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typePrevention
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titleCerclage pessary for preventing preterm birth in Chinese women with a short cervix in singleton pregnancies: a randomized controlled trial
Study objectivesDetermine the effect of cerclage pessary on the incidence of spontaneous delivery between randomization and 34 weeks in women with a short cervix less than 25 mm in a singleton pregnancy
Ethics approval(s)Joint Chinese University of Hong Kong - New Territories East Cluster (CUHK-NTEC) Clinical Research Ethics Committee (Hong Kong)
Health condition(s) or problem(s) studiedCervical insufficiency
InterventionWomen invited to participate were randomized into two arms: control group or pessary group. Randomization was performed using a computer-generated sequence and the allocation results were concealed in sequentially numbered, identical, opaque, sealed envelopes and kept away from the clinic where patients were being assessed. The treatment allocation would only be revealed to the obstetrician in charge after the patient was assessed to be eligible and consented to the trial.

Follow-up visits for ultrasound assessment of fetal growth and cervical length were carried out every four weeks till 34 weeks of gestation. If after 26 weeks the cervical length was less than 10 mm, steroids (four doses of intramuscular injections of dexamethasone 6 mg 12 hours apart) were given. High vaginal swabs were repeated during each follow-up visit to look for any infection.
Intervention typeOther
Primary outcome measurePreterm rate before 34 weeks
Secondary outcome measuresPerinatal morbidities and mortality
Overall study start date01/10/2008
Completion date28/02/2011

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexFemale
Target number of participants4000
Key inclusion criteriaWomen with singleton viable pregnancy undergoing routine morphology ultrasonography at 18 – 24 weeks found to have a cervix less than 25 mm
Key exclusion criteria1. Multiple pregnancies
2. Major fetal abnormalities defined as those that are lethal or require prenatal or postnatal surgery
3. Severe intra-uterine growth restriction (IUGR)
4. Cervical dilatation, painful uterine contractions, history of ruptured membranes, or prophylactic surgical cerclage before randomization
5. Patients who are unconscious, severely ill, mentally handicapped or under the age of 16 years
Date of first enrolment01/10/2008
Date of final enrolment28/02/2011

Locations

Countries of recruitment

  • Hong Kong

Study participating centre

1E, Department of OG
-
-
Hong Kong

Sponsor information

Prince of Wales Hospital (Hong Kong)
Hospital/treatment centre

Shatin, N.T.
-
-
Hong Kong

ROR logo "ROR" https://ror.org/02827ca86

Funders

Funder type

University/education

Chinese University of Hong Kong (Hong Kong)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan