Sequential Screen for Cervical Insufficiency (TVUS Trial)

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. OBJECTIVE To determine the best strategy for cervical length screening in uncomplicated singleton gestations between the gestational ages of 18-28 weeks. Primary outcome: 1) Time required to obtain adequate views of the cervical length. Secondary outcomes: Patient satisfaction with ultrasound experience as measured by patient questionnaire Number of adequate views of the cervix obtained with each approach STUDY DESIGN 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 Patient satisfaction 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.