www.AJOG.org Ultrasound, Fetus, Genetics Poster Session I

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Low lying placenta diagnosed at the time of fetalanatomical survey: are follow up scans needed?Kelley Conroy1, Michael House11Tufts Medical Center, Obstetrics and Gynecology, Boston, MA

OBJECTIVE: The significance of a low lying placenta at the time of thefetal anatomical survey is not well established. The aim of this studywas to assess the rate of resolution and delivery outcomes for cases oflow lying placenta detected at the anatomy survey.STUDY DESIGN: This was a retrospective cohort study of singletonpregnancies with a low lying placenta diagnosed between 14 and 22weeks gestation at a tertiary care center between January 2009 andMay 2013. We collected data on patient demographics, placentallocation, and frequency of resolution. A trial of labor was offered ifthe placenta was > 1 cm from the internal os. For patients thatdelivered at our institution, we reviewed mode of delivery, gesta-tional age, newborn weight, and estimated blood loss.RESULTS: 309 patients were diagnosed with a low lying placentaduring the study period. There were 162 nulliparous women(52.4%). Posterior placentas were more common (62.8%, p¼0.002).The mean distance from the os was 13.4 (+/- 4.0) mm. Of 172patients with follow up scans, 143 (83.1%) demonstrated completeresolution, defined as located > 2 cm from the os. The placenta waslocated 1-2 cm from the os for the remaining 29 cases (16.9%).Thus, all 172 patients were eligible for a trial of labor, resulting in aresolution rate of 100%. Of 128 patients who delivered at ourinstitution, there were 89 (69.5%) vaginal deliveries and 39 (30.5%)cesarean deliveries. The mean gestational age at delivery was 38.4(+/- 2.2) weeks, with only 10 (7.8%) deliveries prior to 37 weeks.One patient required cesarean delivery for bleeding during labor.The remaining cesarean deliveries were performed for indicationsunrelated to vaginal bleeding. Postpartum hemorrhage occurred in13 (14.6%) vaginal deliveries and 4 (10.3%) cesarean deliveries(p¼0.72).CONCLUSION: Among women with a low lying placenta in the secondtrimester, all were eligible for a trial of labor. Follow up scans todocument resolution of a low lying placenta were not necessary inour patient population.

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Ultrasound indicated cerclage in twin pregnancyAmanda Roman1, Vincenzo Berghella1, Ilia Calluzzo2,Adiel Fleischer3, Burton Rochelson31Thomas Jefferson University, Division of Maternal-Fetal Medicine,Department of Obstetrics and Gynecology, Philadelphia, PA, 2Hofstra NorthShore-LIJ School of Medicine, Department Obstetrics and Gynecology,Manhasset, NY, 3Hofstra North Shore-LIJ School of Medicine, Division ofMaternal-Fetal Medicine, Department of Obstetrics and Gynecology,Manhasset, NY

OBJECTIVE: To compare the perinatal outcome in twin pregnancywith short cervical length after ultrasound indicated cerclage (UIC)versus expectant management (EM).STUDY DESIGN: Retrospective cohort study of twin pregnancies withshort cervical length (CL) �25 mm between 16-24 weeks at NorthShore-LIJ Health System and Thomas Jefferson University Hospitalbetween 1995-2012. Exclusion criteria: genetic or major fetalanomaly, multifetal reduction >14 weeks, monochorionic-mono-amniotic, medically indicated preterm birth, intrauterine growthrestriction in at least one twin. Primary outcome: spontaneouspreterm birth (SPTB) �34 weeks. Secondary outcome: SPTB �28,�32 weeks.RESULTS: Forty six women with twin pregnancy and short CL un-derwent UIC and 38 were managed expectantly. Demographic

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characteristics are presented in Table. UIC group presented withshorter CL at earlier GA at diagnosis. After adjusting for CL and GAat presentation, there were no differences in SPTB �28, �32, �34weeks (Figure). Interval from time at diagnosis of short CL to de-livery was not significantly different.CONCLUSION: Ultrasound indicated cerclage in twin pregnancy withCL �25mm before 24 weeks did not decrease SPTB.

SPTB: spontaneous preterm birth; GA: Gestational age; CL: cervical length.

Data shown in mean�SD or percentage. Analysis with t test or Fisher exact

test. Considered significant P value: <0.05.

ent to JANUARY 2014 American Journal of Obstetrics & Gynecology S61