Patient Attitudes Toward Ultrasound Measurement of Cervical Length

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. PROTOCOL 1. 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 2. 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. 3. Patients will be randomized into one of three groups: 1. Standard US evaluation 2. Sequential US evaluation 3. Transvaginal cervical length screening 4. 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. 1. 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 2. 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).