Can Cervical Stiffness in the Second Trimester Predict Preterm Birth in High-Risk Singleton Pregnancies?

Study Overview
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Brief Summary
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Preterm birth (PTB), defined as delivery before 37 weeks gestation, is a common complication of pregnancy and affects up to 1 in 10 women in the UK. PTB is the leading cause of neonatal mortality and morbidity with babies born earliest being at the greatest risk. Identifying women at high risk of having a PTB and offering treatments and intervention to try and prevent this outcome is a huge priority in clinical practice and in government policy. The PRECISION study will explore the use of a new antenatal test of cervical stiffness to try and improve the recognition of women who may deliver early. Current clinical practice involves measurement of cervical length (CL) and fetal fibronectin in women known to be high risk for PTB. However recent research suggests these methods could be improved upon and we may be able to recognise women at risk more reliably and at an earlier stage in the pregnancy if we use cervical stiffness assessments. A licensed, CE-marked, vacuum-aspiration device called the Pregnolia system has been developed to give quantitative cervical stiffness index scores during pregnancy. This study will directly compare cervical length measurements and fetal fibronectin results with cervical stiffness, using the Pregnolia system, during the second trimester in women known to be high risk for preterm birth. The investigators will aim to explore the best possible predictive tool kit bundle for PTB using any combination of these assessments.

Detailed Description
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PRECISION is a single site prospective, exploratory, cohort study of 60 women with a singleton pregnancy who are high risk for preterm birth. Participants will have study assessments at 3 time points in second trimester as part of their routine care in high risk pre-term birth clinic. The study assessments will include transvaginal cervical length scanning, fetal fibronectin swabs and cervical stiffness assessment using the Pregnolia device. Once recruited, participants will remain in the study until delivery and discharge from hospital. The investigators will collect routine clinical data from all participants' notes and electronic hospital records for maternal and neonatal outcomes. All study visits will coincide with routine care and all participating women will receive routine antenatal care throughout their pregnancy as per Saving Babies Lives Care Bundle V2, NICE Preterm Labour and Birth guideline and the North West Regional network preterm birth guideline.

Official Title
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Can Cervical Stiffness in the Second Trimester Predict Preterm Birth in High-Risk Singleton Pregnancies?

Conditions
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Preterm Birth

Intervention / Treatment
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* Device: Cervical stiffness assessment
* Other: Cervical length measurement
* Other: Fetal fibronectin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥ 18 years Singleton pregnancy Able to provide informed consent Meets criteria for high-risk pre-term birth clinic; Previous PPROM <34+0 weeks Previous sPTB <34+0 weeks Previous spontaneous mid trimester miscarriage >16 weeks Exclusion Criteria: Previous cervical surgery including previous trachelectomy, cone biopsy, loop excision or previous cerclage Existing cervical cerclage (vaginal or abdominal) Any cervical pathology at 12 o'clock position on cervix Vaginal bleeding evident on examination Visible, symptomatic cervical or vaginal infections Symptomatic of preterm birth (SROM, cervical dilatation) Known congenital uterine anomalies Known or suspected structural/chromosomal fetal abnormality Known HIV Cervical carcinoma Previous fully dilated emergency caesarean section Non-English speaking if unable to provide suitable verbal translation services (language line) at the time of recruitment or subsequent study visits.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| High risk singleton pregnancy for preterm birth<br> | Device: Cervical stiffness assessment<br>* The cervical stiffness is assessed by using the licensed, CE-marked Pregnolia System, during a sterile speculum examination. The single-use, sterile Pregnolia Probe is placed on the anterior lip of the cervix at 12 o'clock position and a recording of cervical stiffness is generated over maximum 60 seconds (typically ̴15 seconds) and displayed as Cervical Stiffness Index (CSI) in mbar. The measurement is repeated 3 consecutive times without any time lag.<br>Other: Cervical length measurement<br>* Cervical length measurement will be obtained via transvaginal ultrasound using a GE Voluson E10 ultrasound machine and 7.5MHz transvaginal probe. All measurements will be performed with the woman in a supine position with an empty bladder in the sagittal plane measuring from the internal to external cervical OS. The full length of the cervical canal will be visualized with the closed portion of cervix remaining being measured. Three measurements are taken with the shortest being documented as the final assessment.<br>Other: Fetal fibronectin<br>* Vaginal swab collection. The specimen will be obtained from the posterior fornix over 10 seconds using the polyester tipped swab provided in the Hologic specimen collection kit. This sample will be then be stored frozen and processed using the Rapid fFN 10Q System (HOLOGIC, Marlborough, MA, USA) within 3 months.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with Spontaneous preterm birth <34 weeks gestation | We will define sPTB as labour having occurred prior to 34+0 weeks of gestation in patients with either intact membranes or PPROM (<37 weeks). This excludes iatrogenic causes for preterm delivery including induction of labour (in the absence of PPROM) or elective caesarean section. | Gestation at delivery. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Preterm birth, Cervical stiffness, cervical integrity