Patient Attitudes Toward Ultrasound Measurement of Cervical Length (TVUS)
Recruitment status was: Recruiting
The investigators propose a prospective evaluation of methods to assess cervical length for uncomplicated singleton gestations between 18-28 weeks presenting to the MFM office for routine mid pregnancy ultrasound. The investigators hypothesize that a sequential approach to screening of the cervix (which consists of initial transabdominal evaluation first with transvaginal ultrasound reserved only for those patients in whom the cervix appears short on transabdominal exam or when adequate views cannot be obtained with the transabdominal approach alone) will take less time, will result in the same number of adequate views of the cervix and will have higher patient satisfaction that a universal transvaginal screening approach.
To determine the best strategy for cervical length screening in uncomplicated singleton gestations between the gestational ages of 18-28 weeks.
1) Time required to obtain adequate views of the cervical length.
- Patient satisfaction with ultrasound experience as measured by patient questionnaire
- Number of adequate views of the cervix obtained with each approach
This is a prospective study to compare strategies for cervical length measurements in uncomplicated singleton gestations seen in the MFM office for routine mid pregnancy fetal well being ultrasound between 18-28 weeks gestation. The different strategies include 1) Transabdominal assessment of the cervix (current standard), 2) Sequential evaluation of the cervical length (transabdominal followed by transvaginal if necessary due to short cervix or inadequate transabdominal views), and 3) Transvaginal cervical length assessment. Patients with an uncomplicated singleton gestation presenting for a routine mid pregnancy ultrasound between 18-28 weeks will be randomized into one of the three groups noted above after consent is obtained. Ultrasound examination will then take place and data collected. The various strategies listed above will be compared for the following:
Time required to obtain views of the cervix
- Time from initiation of exam to completion of cervical assessment
- Time for completion of entire exam
- Comfort/Discomfort of exam procedure
- Overall impression of exam process
- Number of adequate views of the cervix obtained
Maternal demographics including age, parity, weight, height and due date/gestational age will also be obtained for all consenting patients.
Procedure: Sequential ultrasound
Procedure: Transvaginal ultrasound
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Screening
|Official Title:||Patient Attitudes Regarding Abdominal Versus Transvaginal Ultrasonography for Assessment of the Cervical Length in Low Risk Patients: a Randomized Trial|
- Time [ Time Frame: Assessed on the day of ultrasound (one single visit) ]The time it takes to perform the assessment of the cervix will be recorded, as well as the time it takes to perform the entire exam.
- Patient satisfaction [ Time Frame: Assessed the day of the ultrasound (one single visit) ]Participants will complete a survey indicating their opinions about the ultrasound experience.
- Ultrasound adequacy [ Time Frame: Assessed on the day of the ultrasound (one single visit) ]Assess the frequency with which adequate views of the cervix can be obtained using transabdominal vs transvaginal ultrasonography
|Study Start Date:||November 2011|
|Estimated Study Completion Date:||December 2012|
|Estimated Primary Completion Date:||December 2012 (Final data collection date for primary outcome measure)|
No Intervention: Standard Ultrasound
Current standard of care - one abdominal view of the cervix to rule out placenta previa
Experimental: Sequential Screen
Start with 3 abdominal views of the cervix with measurement. If 3 adequate views cannot be obtained, or if measurement is less than 3cm, then will perform transvaginal scan for measurement.
Procedure: Sequential ultrasound
Abdominal ultrasound first; obtain 3 adequate measurements. If 3 adequate views not obtained or if measurement less than 3 cm, perform transvaginal ultrasound for measurement.
Experimental: Screening Transvaginal Ultrasound
Obtain 3 adequate cervical length measurements using transvaginal ultrasound
Procedure: Transvaginal ultrasound
Obtain 3 transvaginal ultrasound cervical length measurements
BACKGROUND AND SIGNIFICANCE
Preterm birth is a significant problem in the United States and worldwide. Approximately twelve percent of births in the US occur before 37 weeks and are considered preterm. Of these, 80% are considered "spontaneous preterm deliveries" (as opposed to iatrogenic) and are related to preterm labor or preterm rupture of membranes (Arias, 2003). Certain pregnancy characteristics have been identified to determine those patients at risk for preterm delivery. These include a history of preterm birth (Esplin, 2008), uterine anomalies, multiple gestation, among other things, both modifiable and not (Gardosi, 2000; Ananth, 2006). However, an important risk factor that can be identified is the presence of specific changes in the cervix, such as cervical shortening, and in fact, studies indicate that the risk of spontaneous preterm birth increases as cervical length decreases (Iams, 1996; Hibbard, 2000).
Some authors now advocate the universal screening of all pregnant women for cervical shortening at the time of the ultrasound that is performed at 18-28 weeks in most women. However, the best approach to evaluate the cervix in low risk patients (those without an identifiable risk factor) remains controversial.
- Patients will be identified in the Maternal Fetal Medicine office and consented for randomization at the time of presentation for previously scheduled mid-trimester ultrasound
- Patients will be given randomly generated treatment allocations within sealed opaque envelopes. Once a patient has consented to enter the trial, the envelope will be opened by the ultrasonographer to determine the assigned treatment regimen.
Patients will be randomized into one of three groups:
- Standard US evaluation
- Sequential US evaluation
- Transvaginal cervical length screening
Maternal demographics including maternal age, height, weight, parity, and gestational age will be collected from the patient as part of the patient questionnaire. Ultrasound exam data including measurements of the fetal biometry, presence of fetal anomalies, placental location and amniotic fluid volume will be collected from the official ultrasound report.
- Patients will be assigned a unique study ID number at the time of enrollment and all information including time of ultrasound procedures, clinical data and adequacy of cervical measurement will be linked by the ID number
- All data will be entered into an electronic data base in a de-identified fashion and kept in a secure, encrypted web-based database management program (RedCap).
Please refer to this study by its ClinicalTrials.gov identifier: NCT01482039
|United States, Utah|
|Intermountain Medical Center|
|Salt Lake City, Utah, United States, 84177|
|Principal Investigator:||Stephanie T Romero, MD||Intermountain Medical Center|