Official Proceedings - AIUM

American Institute of Ultrasound in Medicine Proceedings J Ultrasound Med 32(suppl):S1–S134, 2013pict the fetus in the same midsagittal plane required for nuchal translucencymeasurement. Subsequently, to ensure uniformity in the approach,standardization, a prerequisite for automation, had to be completed in 2 ofthe 3 orthogonal planes prior to navigating through the volume to commencethe navigation from the plane of the transverse abdominal circumference.This was accomplished by placing the reference dot in the fetalspine at the level of the diaphragm in plane A, generating a transverseplane of the fetal abdomen with the fetal stomach visible in plane B. PlaneB was then chosen as the designated reference plane 0 from which to navigatewithin the volume. We coined this standardized approach the midsagittalvolume technique, and it was carried out on all the volume data setsprior to navigating through each volume. Parallel shift was used startingfrom plane 0, and the spatial relationships to 7 planes (5 cephalad and 2caudad) were established. The median and range were calculated for eachof the planes, and they were evaluated as a function of the fetal crownrump length. P < .05 was considered statistically significant.Results—A total of 63 volume data sets were analyzed. The 8anatomic planes were found to adhere to normal distribution curves, andmost of the planes were in a definable relationship to each other with statisticallysignificant correlations.Conclusions—To our knowledge, this is the first study to describethe possible spatial relationships between eight 2D anatomic planesin the 11 + 6- to 13 + 6-week fetus, using a standardized approach. Definingthese spatial relationships may serve as the first step for the potentialfuture development of automation software for fetal anatomic assessmentat 11 + 6 to 13 + 6 weeks.1537670 Does Cervical Cerclage Placement Prolong Gestation inTwin Pregnancies With a Sonographically Short Cervix?Sara Brubaker,* Samantha Do, Noelia Zork, Cara Pessel,Joy Vink, Annette Perez-Delboy, Sreedhar GaddipatiObstetrics and Gynecology, Columbia University Medical Center,New York, New York USAObjectives—There are limited data to support the use of cervicalcerclage in twin pregnancies. The practice has become less commonsince the 2005 publication of a meta-analysis that revealed an increasedrisk of adverse pregnancy outcomes among twin pregnancies in which acerclage was placed. The practice continues, however, likely driven in partby patient request. Our objective was to compare gestational age at deliveryamong patients with twins and a short cervix who underwent cerclageplacement with those who did not.Methods—We created a retrospective database of twin gestationsthat were diagnosed with a short cervix (cervical length ≤2.5 cm)between 2004 and 2012 at our institution. Mean gestational age (GA) atdelivery was compared in women who did and did not undergo cerclageplacement using a 2-sample t test. The relative risk (RR) of delivery priorto 32 and 34 weeks’ gestation was compared using a 2-sided χ 2 test.Results—Of the 158 women that met the inclusion criteria, 25underwent cerclage placement. The mean GA at delivery in the cerclagegroup was 32.6 weeks vs 33.8 weeks for the no-cerclage group (P = 0.77).The RRs of delivery at