Transvaginal Ultrasound Cervical Length Measurements in Twin Gestations

Study Overview
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Brief Summary
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The purpose of this study is to determine if the use of routine transvaginal cervical length ultrasound can be used to prevent preterm deliveries in twin gestations.

Detailed Description
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This is a randomized controlled trial to determine whether there is a difference in the rate of preterm birth among women with twin pregnancies whose clinicians are aware of transvaginal ultrasound cervical length measurements compared to those managed without this information. The study group had transvaginal cervical length ultrasound monthly from 16-28 weeks and were managed with a standard algorithm for activity restriction and cerclage depending on the cervical length. The control group had digital cervical exams and routine transvaginal cervical length ultrasound was not utilized. The primary outcome was the mean length of gestation. Secondary outcomes included percentage of deliveries < 35 weeks, maternal and neonatal outcomes.

Official Title
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Use of Transvaginal Ultrasound Cervical Length Measurements in Twin Gestations

Conditions
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Pregnancy

Intervention / Treatment
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* Other: Transvaginal ultrasound determination of cervical length
* Other: Routine care


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Twin pregnancy Gestational age < 20 weeks Exclusion Criteria: History of incompetent cervix with plans to place a cerclage History of possible cervical incompetence with preexisting plans to monitor cervical length Prior preterm birth at < 28 weeks gestational age Plans to leave the area before delivery Known major fetal anomaly Known diagnosis of twin-twin transfusion syndrome Age < 18 Monoamniotic twins

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Transvaginal Cervical Length Group<br>Clinicians managing the patients were aware of the transvaginal cervical length ultrasound measurements. | Other: Transvaginal ultrasound determination of cervical length<br>* Transvaginal ultrasound was used to measure the length of the cervix from the internal to external os relying on a standard approach and clinicians caring for the patients were made aware of the results.<br>|
| Other: Routine Care<br>Clinicians managing the patients were not aware of any transvaginal cervical length ultrasound measurements. | Other: Routine care<br>* Routine prenatal care of twins. Digital exams were permitted, but transvaginal ultrasound assessment of cervical length was not.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gestational age at delivery | Gestational age reported as completed weeks of gestation | Immediately at the time of delivery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Preterm birth at < 35 completed weeks of gestation | The proportion of women delivering preterm at less than 35 completed weeks of gestation. | Immediately at the time of delivery | 
| Number of days of maternal bed rest | The number of days a woman was instructed to remain at bed rest or home rest before delivery | Immediately at the time of delivery | 
| Number of maternal days in the hospital | The number of antenatal hospital days not including the postpartum stay | Immediately at the time of delivery | 
| Use of tocolytic medications | Any use of tocolytic medications prior to delivery | Immediately at the time of delivery | 
| Administration of steroids | Any use of steroids for the promotion of fetal lung maturity | Immediately at the time of delivery | 
| Birth weight | Newborn birth weight | Immediately at the time of delivery | 
| Length of stay in the neonatal intensive care unit | Total days spent in the neonatal intensive care unit | Newborns will be followed throughout their hospital stay for an anticipated average of 2 weeks | 
| Severe neonatal morbidity | Composite outcome defined as one or more of the following: neonatal death, mechanical ventilation after 72 hours of life, chronic lung disease, grade 3 or 4 intraventricular hemorrhage or periventricular leukomalacia, necrotizing enterocolitis, stage 3 or higher retinopathy of prematurity, culture proven sepsis, or hemodynamic instability requiring pressor medications after 72 hours of life | Newborns will be followed throughout their hospital stay for an anticipated average of 2 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Twins, Twin gestation, Preterm birth, Prevention